EFFECTS OF TWO DIFFERENT TAPERING MODELS ON MAXIMAL STRENGTH GAINS IN RECREATIONALLY STRENGTH TRAINED MEN Stina Seppänen

Transcription

1 EFFECTS OF TWO DIFFERENT TAPERING MODELS ON MAXIMAL STRENGTH GAINS IN RECREATIONALLY STRENGTH TRAINED MEN Stina Seppänen Masters thesis in Science of Sport Coaching and Fitness Testing Faculty of Sport and Health Sciences University of Jyväskylä Spring 2018 Supervisor: professor Keijo Häkkinen

2 ABSTRACT Seppänen, S Effects of two different tapering models on maximal strength gains in recreationally strength trained men. Faculty of Sport and Health Sciences, University of Jyväskylä, Master s thesis in Science of Sport Coaching and Fitness Testing, 79p. Tapering is the last part of a periodized training program and the goal of the taper is to peak the performance. A tapering period can be performed in different ways and there are four tapering models which are often used. The purpose of this study was to compare the effects of two different tapering models on maximal strength performance and mechanisms behind the changes in performace. The study consisted a one-week control period, an eight-week training period and a two-week tapering period. The subjcts were year-old strength trained men. All subjects followed the same training protocol for the first eight weeks and therafter the subjects were divided into two tapering groups: step (group 1) and exponential (group 2). In the step tapering group the training volume was reduced by 54 % at once and was then remained at this level during the both tapering weeks. In the exponential taper group the volume was reduced by 42 % for the first week and by 66 % for the second week. The following measurements were taken before and after the training and tapering period: 1RM squat, 1RM bench press, maximal isometric bilateral leg press, blood samples (CK, testosterone, cortisol, SHBG), EMG of vastus lateralis, cross-sectional area of vastus lateralis and body composition. Both groups increased their 1RM squat (group 1: 13.3±6.94 %, p=0.002; group 2: 15.6±7.05 %, p=0.000) and 1RM bench press (group 1: 9.48±3.62 %, p=0.000; group 2: 10.40±4.63 %, p=0.001) statistically significantly during the eight-week training period. The two-week tapering period led to further statistically significant increases in 1RM squat (group 1: 3.36±2.08 %, p=0.003; group 2: 1.72±0.89 %, p=0.004). There was a positive trend towards significance in improvements of 1RM bench press (group 1: 2.02±2.03 %, p=0.099; group 2: 1.42±1.59 %, p=0.076) after the tapering period. No significant differences were observed between the groups. AEMG of vastus lateralis ( ms) increased significantly in group 1 during the taper (post 8-taper 2: 22.59±22.13 % p=0.028; taper 1-taper 2: 24.30±19.32 %, p=0.011). AEMG of VL increased significantly from taper 1 to taper 2 ( ms: p=0.046; ms: p=0.015) and there was a positive trend towards significance from post 8 to taper 2 ( ms: p=0.080) when the groups were combined. The T/SHBG ratio increased significantly in group 2 after the taper (16.09±10.84 %, p=0.022). Creatine kinase concentration decreased during the taper in both groups (group 1: ±19.56 %, p=0.080: group 2: ±20.51 % p=0.156) and the reduction was significant when the groups were combined (p=0.044). Reduced volume tapering seems to be an effective way to improve maximal strength performance. It seems that both, step and exponential tapers, can lead to improvents in maximal strength. Enhanced recovery of the neuromuscular system, an enhanced hormonal profile and reduced rate of muscle damage may explain the improved strength performance after the taper. Key words: Tapering, maximal strength, strength training

3 ACKNOWLEDGEMENTS The present study was carried out in the Neuromuscular Research Center, Biology of Physical Activity at the University of Jyväskylä. I am grateful for the financial support from the Neuromuscular Research Center that made the hormonal analyses possible. The project produced two Master s theses and one Bachelor s thesis. Only the protocols, procedures and measurements relevant to the topic of this thesis are presented here. I woud like to acknowledge the Neuromuscular Research Center, Biology of Physical Activity and especially my supervisor Professor Keijo Häkkinen who s advices, guidance and encouragement has been invaluable. I would also like to thank my friend and co-worked Minttu Virtanen, all the participants who made this study possible, the technical staff (Risto Puurtinen, Aila Ollikainen, Pirkko Puttonen, Jukka Hintikka, Markku Ruuskanen and Sirpa Roivas) and all the students who were helping us during the project.

4 LIST OF CONTESTS ABSTRACT 1 INTRODUCTION STRENGTH TRAINING Strength training variables Intensity Volume Adaptations to strength training Neural adaptations Hormonal adaptations Skeletal muscle adaptations PERIODIZATION Periodization of strength training Modelling training responses Overreaching and overtraining Detraining TAPERING Principles of tapering and manipulation of training variables Volume and intensity Duration of the taper and training frequency Mechanisms behind improved performance during and after a taper period Changes in hormone concentrations Changes in the neuromuscular system Changes in body composition Tapering strategies in powerlifting TAPERING MODELS RESEARCH QUESTIONS AND HYPOTHESES METHODS Subjects Experimental design Training program Data collection and analyses Timetable of the measurements and measurement instructions Neuromuscular performance Isometric performance... 51

5 Dynamic performance Muscle activity measurements Body composition and muscle mass measurements Blood sampling and analyses Statistics RESULTS Neuromuscular performance Hormone and creatine kinase concentrations Body weight and muscle cross-sectional area Effects of tapering on different variables Correlations DISCUSSION REFERENCES... 72

6 1 INTRODUCTION How to get the peak performance out of you in a given day? Tapering is the last part of a periodized training program and the goal of the taper is to peak the performance. Le Meur (2012) et al. and Mujika & Padilla (2003) are describing the taper as a progressive nonlinear reduction of the training load during the variable period of time, in an attempt to reduce the physiological and psychological stress of daily training and optimize sports performance. Tapering can be performed in many ways. Effects of different tapering models on maximal strength have not been investigated well yet. Some research has been done and it has been noticed that tapering might have a positive effect on maximal strength. Lowering the training volume and maintaining or increasing the intensity during the taper seem to have positive effects on maximal strength (Häkkinen et al. 1991, Gibala et al. 1994, Rhibi et al. 2016, De Lacey et al. 2014, Bosquet et al etc). In previous studies it has been noticed that a reduction of % in training volume is a more effective way to optimize the performance than decreasing the intensity. (Pritchard et al. 2015a) It has also been noticed that decreasing the duration of each training session is more effective than decreasing the training frequency (Bosquet et al. 2007). There are four different types of taper which are used to optimize sport performance. These models are step tapering, linear tapering and exponential tapering (either a slow or fast time constant of decay). Even though every of these models are widely used, there are only few studies which have compared different models directly. (Mujika & Padilla ) It has been shown that both, step and progressive tapers, can increase maximal strength, but there are no studies which have compared the effects of different tapering models on maximal strength performance directly (Pritchard et al. 2015a). The optimal length of the tapering period is unclear. It is not well known yet where is the time point which separates the benefits of the taper from the negative outcomes of reduced training Usually the length of the taper is around 4-28 days, but it has been noticed that variability between different people is large, so the duration of the taper must be individually determined. (Mujika & Padilla 2003.) 1

7 The mechanisms behind the improved maximal strength after the tapering period are also unclear. Changes in the nervous system and at hormonal level may have a role in improved performance (Häkkinen et al , Häkkinen et al. 1987, Izquierdo et al. 2007, Coutts et al , Pritchard et al. 2015a.) Also changes in muscle mass and in muscle architecture may be potential factors behind improved performance (Pritchard et al. 2015a). The purpose of the present study is to compare the effects of two different tapering models on maximal strength gains in recreationally strength trained men and to investigate possible mechanisms behind the changes in maximal strength performance during/after the tapering period. 2

8 2 STRENGTH TRAINING 2.1 Strength training variables Strength training has become one of the most popular types of exercising. The purpose of strength training is to enhance muscular strength. In many sports, strength is one of the most important factors and for sedentary people muscular strength can provide many benefits. (Fleck & Kraemer 2014 p. 1.) Systematic strength training can change the structure of the body and produce functional changes. When training progressively and continually challenges the body and enough recovery time is provided, the body adapts to training by becoming stronger. The size of the adaptations depens on individual s capability to adapt onto the stress placed on the body. (Bompa & Buzzichelli 2015 p. 29, Bird et al.2005.) The key training principles in strength training are the overload and specificity, progression and individualisation, adaptation and maintenance (Bird et al. 2005). Strength training can be altered via different program variables. Fleck & Kraemer have defined five acute program variables which are: choice of exercise, exercise order, intensity/load of exercise, exercise volume and rest periods. (Fleck & Kraemer 2014 p. 187.) American College of Sports Medicine has updated the list of program variables and acute program variables described by ACSM are muscle action, loading and volume, exercise selection and order, rest periods, repetition velocity and frequency. (Bird et al ) It is impossible to dissociate the effects of the different training variables completely; the outcome of the training is always dependent on all the variables in the training program. (Fry 2004.) Strength training program variables can be altered depending on the goal of the program. Table 1 shows basic guidelines for building the program for muscular hypertrophy and maximal strength. (Kraemer & Häkkinen 2002 p. 72.) It has been noticed that for enhancing maximal strength fewer reps and higher loads are required than for building muscular hypertrophy (Häkkinen 1994). 3

9 TABLE 1. General guidelines for hypertrophy and maximal strength types of training. (modified from Kraemer & Häkkinen 2002 p. 72.) Hypertrophy Maximal Strength Repetitions Sets Rest Periods sec 2-5 min Exercises Single- and multijoint Single- and multijoint Exercise Order Large to small muscles Large to small muscles Intensity Intensity is one of the most effective controllable training variables while the goal is to enhance muscular strength (Fisher et al. 2013). All the training variables effect on the outcome of the traning but the load used seems to be the most important one for gains in maximal strength (Fry 2004). This goes hand in hand with the principle of specificity, i.e. adaptations are training type specific (Bompa & Haff 2009 p. 9). Intensity is often defined as a percentage of maximal strength (% 1RM) and this is called relative intensity. Mean intensity for the session can be calculated from the work sets performed and it includes all the sets, reps and exercises. (Fry 2004.) Intensity can be also defined by a more subjective manner as a percentage of effort. A commonly used method to determine the percentage of effort is the rating of perceived exertion, RPE. (Fry 2004.) The original RPE scale with the rating from 6 to 20 was created by Gunnar Borg. This scale was mainly developed to match the heart rate and, therefore, it is useful for endurance training. The Borg CR10 scale uses exertion ratings from 1 to 10. For resistance training the Reps in Reserve (RIR) scale seem to be more useful than original RPE scales. With the RIR scale (table 2) athletes can estimate how many reps they have in reserve after a work set with a given load/intensity. (Helms et al ) It has been noticed that the RIR scale is more accurate when a set is closer to failure and with more experienced athletes. (Hackett et al. 2012, Zourdos et al ) 4

10 TABLE 2. Repetitions in the reserve (RIR) scale for estimating reps in reserve after the set. (Zourdos et al ) Hackett et al. (2012) used a modified version of the RPE scale and estimated-repetition-tofailure scale to estimate the effort of the squat and bench press work sets in competitive male bodybuilders. They concluded that there was a high correlation between the RPE and repetition-to-failure scale, but RPE at volitional fatigue was less than maximal. There was also a high positive correlation between estimated-repetitions-to-failure and actualrepetitions-to-failure. (Hackett et al ) Zourdos et al. (2015) obtained similar results in their study. There was a significant inverse relationship between RPE/RIR and average velocity at various percentages of 1RM in experienced and novice squatters. They concluded that RIR seems to be a valid method for assigning training load and session-to-session load progression. Different intensities can be used in strength training programs. Optimal maximal strength gains in strength-trained people seem to be achieved by using the intensities over 80 % of 1RM. This intensity level is also needed for maintaining the strength levels. When the intensity was reduced to % of 1RM for few weeks maximal muscle activation level decreased in strength athletes. (Häkkinen et al ) In untrained people the required mean intensity seems to be around 60 % of 1RM for optimal strength gains (Rhea et al. 2003). 5

11 Fry (2004) concluded in his review paper that maximal hypertrophy occurs in load ranges of % of 1RM. Relative intensity accounts approximately % of the hypertrophy response (Fry 2004). Häkkinen (1994) concluded that loads between % of 1RM lead to ultimate muscular hypertrophy when each set is performed until concentric failure. On the other hand, Schoenfeld et al. (2015) noticed that training with light loads may lead to muscular hypertrophy to about same extent than training with heavy loads in well-trained men when the sets are performed to concentric failure. However, training with heavy loads leads to higher gains in strength. (Schoenfeld et al. 2015). It has been discussed that the recruitment of motor units and muscle fibres are crucial to stimulate muscular growth. What has caused the recruitment may be secondary because the activation of the muscle fibres stimulates muscular responses and this enhances hypertrophy. (Fisher et al ) It seems that training with higher intensity is required when maximal strength is the goal of the program, but hypertrophy can be also achieved with moderate intensities Volume A total amount of work performed in a training session is known as volume. Volume can be calculated as total repetitions (sets x reps) or as a volume load (sets x reps x load). (Bird et al ) Training volume can be increased by adding sets, load, exercises or by increasing training frequency (Fleck & Kraemer 2014 p. 7). It has been noticed that higher training volumes correlates with hypertrophy and strength gains. Krieger (2009) concluded in his meta-analysis that 2-3 sets/exercise led to 46 % greater strength gains than 1 set/exercise in trained and untrained subjects. Multiple sets per exercise have also resulted in greater increases in muscle size than only a single set per exercise. Smilios et al. (2003) noticed that growth hormone response was higher after 4 sets of 10 repetitions compared to 2 and 6 sets. This higher growth hormone response may be one explanation why multiple sets enhance muscular strength and hypertrophy until to a higher extent. Schoenfeld et al. (2017b) noticed in their meta-analysis that over 10 sets/muscle/week increased muscle mass more than under 10 sets/muscle/week. However, it is not clear yet if even higher volumes per muscle would be beneficial or not for hypertrophy. (Schoenfeld et al. 2017b.) 6

12 It has been discussed whether there is a volume threshold after which performance gains will be impaired. A too high volume may lead to decreases in strength levels. However, improvements in performance may be seen when training volume is returned back to normal levels after a high-volume period. This is called a rebound effect. (Fry & Kraemer 1997.) Häkkinen et al. (1987) noticed this rebound effect in their study. After a high-volume training period the weightlifting result was decreased but after 2 weeks of normal training and a 2- week peaking period the weightlifting total improved over the pre-level. Gonzalez-Padillo et al. (2005) compared effects of low, high and moderate training volumes on strength gains in experienced junior weightlifters. They concluded that moderate training volumes were more beneficial than low or high training volumes. As seen in figure 1 training with moderate volume led to significant improvements in the snatch, clean&jerk and squat strength, whereas low and high training volume groups showed significant improvements only in squat and clean&jerk exercises. It seems that in experienced (>3 years of strength training experience, training 4-5x/week) lifters increasing training volume over a certain point does not lead to further improvements in performance during a short period of time. (Gonzalez-Padillo et al ) 7

13 FIGURE 1. Comparison of different training volumes and improvements in snatch, clean&jerk and squat exercises. (Gonzalez-Padillo et al ) The frequency of training describes the amount of training sessions performed in a given period of time, typically in one week. For previously untrained individuals 2-3 days/week seem to be effective for gaining strength. When training age increases, 3-4 days/week or 4-6 days/week may be beneficial. (Bird et al ) 8

14 2.2 Adaptations to strength training Body adapts to strength training by becoming stronger. The purpose of strength training is to provide a stimulus to the body onto which it needs to adapt via different systems and these adaptations of the different systems lead to enhanced strength. The basic principle behind progression is the overload principle. For achieving the higher strength levels, the body needs to be challenged over and over again. (Häkkinen 1994.) Strength training places mechanical and metabolic stress onto the body. High intensity (i.e. higher loads) causes higher mechanical stress and more muscle activation. Mechanical stress is sensed by skeletal muscles and it is thought that this applied tension stimulates the release of growth factors. If the tension is higher on which the muscles are generally used an inflammatory response may also occur. Strength training also produces stress for the metabolic system. Higher training volumes and shorter rest periods creates higher metabolic stress. This type of training results in high fatigue and this may stimulate greater anabolic hormone responses. Mechanical stress seems to be a more important factor for muscle strength and hypertrophy gains in well-trained individuals. (Mangine et al ) Neural adaptations Strength training results in neural adaptations. Neural adaptations can occur at all stages of strength training. Moritani & De Vries (1979) noticed that early changes in maximal strength are strongly related to neural factors. As seen in figure 2 during the first 4 weeks of training, gains in maximal strength are mostly explained by neural factors. After this time frame the role of muscular hypertrophy as a contributor of maximal strength gains increases. (Häkkinen 1994.) However, the neural adaptations occur in trained individuals also. 9

15 FIGURE 2. Factors behind improved maximal strength. (Häkkinen 1994, modified from Moritani & De Vries 1979.) Neural adaptations can be divided to disinhibition of inhibitory mechanisms and improvements in intra- and intermuscular coordination. Golgi tendon organs, Renshaw cells and supraspinal inhibitory signals are inhibitory mechanisms which effect on strength production. (Häkkinen 1994, Bompa & Buzzichelli 2015 p ) Intra- and intermuscular adaptations for strength training will increase muscle activation, increased frequency of doublet firing, enhanced motor unit synchronization, increased motor unit firing rates and alterations in agonist-antagonist co-activation ratios. (Häkkinen 1994, Gabriel et al ) Balshaw et al. (2017) noticed that changes in agonist (quadriceps) neural drive correlated with the percentage changes of MVT (maximal voluntary torque). This change in agonist neural drive was the most important predictor of the changes in MVT. The authors noticed also that along with the changes in agonist neural drive the changes in quadriceps volume and the pretraining strength status explained approximately 60 % of the variance in the strength changes after a knee extensor resistance training period. (Balshaw et al ) Training intensity seem to have a high impact on the training-induced neural adaptations as shown in figure 3. In strength trained athletes training with loads below 80 % of 1RM decreased the maximum iemg. When the training intensity was increased to % of 1RM or higher, the maximum iemg increased. (Häkkinen et al ) Increased iemg values results from improved motor unit firing frequency and/or increased number of the active motor units. It seems that in well-trained subjects the training intensity >80 % is 10

16 required for maintaining and improving voluntary neural activation of muscles. (Häkkinen 1994.) FIGURE 3. Mean maximum iemgs of vastus lateralis (VL), vastus medialis (VM) and rectus femoris (RF) muscles in the isometric contraction in male strength athletes during heavy strength training for 12 weeks. (Häkkinen et al ) Most of the adaptations of the neuromuscular system can be achieved by training with loads lower than 90 % of 1RM as seen in table 3. Intermuscular coordination can be highly achieved with loads under 80 % of 1RM but increases in intramuscular coordination requires loads over 80 %. (Bompa & Buzzihelli 2015 p. 31.) 11

17 TABLE 3. Resistance training induced neural adaptations. (Bompa & Buzzichelli 2015 p. 32.) Nordlund Ekblom (2010) noticed that a 5-week plantar flexor strength training period led to increased plantar flexor strength and voluntary activation measured by twitch interpolation technique. Knight & Kamen (2001) noticed also that a 6-week resistance training period improved isometric strength of knee extensor muscles in young and old individuals and voluntary activation of quadriceps muscles increased 2 % in both groups. (Kinght & Kamen 2001.) However, Judge et al. (2003) noticed that a sport-specific strength training period resulted to increased knee extension MVC strength and iemg values of quadriceps muscles but did not increase the level of voluntary activation measured by interpolated twitch technique in highly skilled athletes as seen in the figure 4. The authors concluded that the increased iemg values and knee extension MVC torque resulted from improved neural drive but no changes in voluntary activation were observed. (Judge et al ) Findings of Judge et al. (2003) were in line with the findings of Herbert et al. (1998). Herbert et al. (1998) noticed that an 8-week isometric strength training of elbow flexor muscles led to increased strength of elbow flexor muscles, but voluntary activation levels did not change. The rate of the voluntary activation was already high (96.2 +/- 0.5 %) prior to training. Based on the findings of these studies it seems that voluntary activation measured by interpolated twitch technique may be improved after a resistance training period, but the findings are inconclusive. 12

18 FIGURE 4. A) Changes in knee extension isometric maximal voluntary contraction (MVC) torque and B) changes in maximal voluntary activation. (Judge et al ) Hormonal adaptations Strength training can elevate the circulating concentrations of anabolic hormones, such as testosterone, growth-hormone and insulin-like growth factor-1 (IGF-1). These elevations may be related to muscle growth by initiating intracellular reactions which are related to muscle growth. (Mangine et al ) Changes in testosterone and cortisol concentrations seem to be related to resistance-training adaptations in trained athletes and subjects (Crewther et al. 2011). Testosterone is an anabolic hormone and it enhances muscle growth (Vingren et al. 2010). A higher testosterone/cortisol ratio seems to correlate positively with the gains in maximal isometric force as seen in figure 5. While the T/C ratio is decreased, a drop in maximal isometric strength can be also observed. This relationship may be related to the anabolic/catabolic state of the body. When the T/C ratio is higher, an anabolic state occurs in the body, hence is it able to repair and build muscle tissue. (Häkkinen et al ) 13

19 FIGURE 5. Correlation between the changes in maximal isometric force and testosterone/cortisol ratio at later phases of a 6-month trainig period. (Häkkinen et al. 1985) Trembley et al. (2003) noticed that after a resistance training session total and free testosterone increased and in resistance-trained subjects the levels declined below the baseline levels after the recovery. Cortisol levels increased also after a resistance training session. In resistance-trained subjects the hormonal responses after a resistance training session were higher than in endurance trained subjects. (Trembley et al ) Ahtiainen et al. (2003) noticed also increases in basal testosterone and free testosterone concentrations during the first 14 weeks of the resistance training period in male strength athletes. During the following 7 weeks the basal and free testosterone concentrations decreased. The training volume was reduced during this second phase of the training program and it may explain these findings. Häkkinen et al. (1987, 1988) have also noticed that serum testosterone concentrations differs regarding to the volume and/or intensity of the strength training period. It seems that testosterone concentrations are connected to training volume and/or intensity in well-trained men. (Häkkinen et al. 1987, Häkkinen et al. 1988, Ahtiainen et al. 2003). However, in previously non-trained subjects no changes in testosterone concentrations were observed in Ahtiainen et al. (2003) study. The authors concluded that it may be that periodical changes in hormonal concentrations are required for strength development of strength athletes but previously untrained subjects may gain strength even without these periodical changes of testosterone concentrations. (Ahtiainen et al ) Changes in the testosterone/shbg ratio have been also observed during a resistance training period. Häkkinen et al. (1987) noticed that after a 2-week stressful training period the 14

20 T/SHBG ratio decreased significantly in male athletes. During this period the T/C ratio decreased significantly as well. This stressful training period was followed by a 2-week normal training period. During this normal training period the T/SHBG ratio increased significantly and remained at the same stage during the reduced training period. Circulating testosterone levels did not change during this period but circulating cortisol and LH concentrations decreased. It seems that the T/SHBG ratio and cortisol levels are related to strength training volume. When the volume is high cortisol levels increases and the T/SHBG ratio and performance level may decrease. (Häkkinen et al ) Skeletal muscle adaptations Skeletal muscle tissue responds to strength training by becoming larger. Muscle can grow by increasing the fibre size, number of the fibres or the amount of connective tissue. Fibre crosssectional area (CSA) can be used as a measurement of hypertrophy. Muscle strength and muscle CSA are related to others. (Rhea et al ) Brachue et al. (2002) also noticed that in elite male powerlifters their powerlifting performance was significantly related to fat-free mass. There was a strong correlation between the performance and muscle thickness. (Brachue et al ) Resistance training will stimulate the growth of all three major fibre types (type I, IIa and IIb) (Bird et al. 2005). Tesch et al. (1987) noticed that a 6-month heavy resistance training period increased the mean fibre area of fast-twitch muscle fibres by 16 %, but there was no increase in slow-twitch mean fibre area. It has been noticed that in weightlifters and powerlifters type II muscle fibre hypertrophy is preferential whereas in bodybuilders both muscle fibre types seem to be equally hypertrophied. This difference may be related to different training methods used among power- and weightlifters compared to bodybuilders. (Fry 2004.) 15

21 3 PERIODIZATION 3.1 Periodization of strength training Periodized strength training seems to be more effective for building strength than nonperiodized strength training. Progressive overload leads to greater adaptations and progression of a training program can be controlled with periodization. (Rhea & Alderman 2004.) In a traditionally periodized strength training program training is divided into different phases to gain morphological adaptations (hypertrophy phase) and neural adaptations (maximal strength and strength power phases). Traditional periodization is also known as a strengthpower periodization or linear periodization. (Hartmann et al , Apel et al ) The main idea behind traditional periodization is to progressively increase the intensity and reduce the volume over the time; the intensity will peak during the peaking phase. (Hartmann et al. 2015). The alteration of program variables follows this linear trend as shown in figure 6. During the strength/hypertrophy phase, also known as an anatomical adaptation/preparation phase, the main goals are to increase short-term work capacity, build muscle, develop neuromuscular balance and build a neuromuscular and conditioning foundation. Typical for this phase is high training volume and relatively low intensity. The strength/power phase also known as a first transition phase follows the preparation phase. During this phase the intensity starts to increase to higher levels and volume starts to drop. In the competition/peaking phase the intensity reaches the highest values and simultaneously the volume is on the lowest point. (Kraemer & Häkkinen 2002 p , ) 16

22 FIGURE 6. A traditional periodization model. (Kramer & Häkkinen 2002 p. 56.) In undulating periodization training variables are rotated daily, weekly or bi-weekly. For example, in weekly undulating periodization hypertrophy and strength-power phases are alternated weekly. (Hartmann et al ) In undulating training programs, the volume and intensity are manipulated irregularly unlike in traditional strength training programs. In the undulating program one week may consist both high-volume and high-intensity sessions as seen in figure 7. (Apel et al ) It has been noticed that with the daily undulating periodization strategy subjects with low or intermediate performance level have increased their maximal strength equally or statistically significantly more than with traditional periodization (Hartmann et al ). 17

23 FIGURE 7. Example of load alteration during one week of undulating strength training program. (Bompa & Buzzichelli 2015 p. 97.) Both linear and undulating training programs seem to be effective for building strength. In the study by Buford et al. (2007) linear, daily undulating and weekly undulating periodization models were used for nine weeks with recreationally trained subjects. There were no significant differences in leg press or bench press strength gains between the groups. Prestes et al. (2009) obtained similar results in their study. They noticed that linear and daily undulating periodization enhanced muscular strength in recreationally trained men. Performance gains were higher in the DUP group but there was no statistically significant difference between the groups. However, Apel et al. (2011) observed that traditionally periodized strength training enhanced back squat, flat benchpress and lat-pull down strength more than a weekly undulating program. Both groups showed similar strength gains after 8 weeks of training, but the traditional group showed significantly greater strength gains at week 12 compared to the undulating group. It seems that both periodization models can be effective when the goal is to increase the strength levels. 3.2 Modelling training responses There are different models which are built for predicting training responses. Coaches and scientists try to predict the outcomes of the training and plan out an effective training program with these models. Hans Seley created a General Adaptation Syndrome (GAS) in The Seley s model describes how the biological system deals with the stressors it meets. (Kraemer & Häkkinen 18

24 2002 p. 143.) This model was not build directly for modelling training responses, but it is suitable for this purpose also because training can be treated as a stressor for the body. As seen in figure 8 the model consists three different phases: an alarm reaction, the stage of resistance and the stage of exhaustion. (Seley 1950.) The alarm reaction will occur after a training session if training has been hard enough to shock the homeostasis. If the training stimulus is too intensive and the stimulus is repeated too often, an exhaustion state may occur. When stressful training stimulus is provided with suitable frequency and long enough recovery time is provided to the system, the system can build resistance against the stimuli and improved performance will occur. (Kraemer & Häkkinen 2002 p ) FIGURE 8. General adaptation syndrome. (Kraemer & Häkkinen 2002 p. 143) Another way to model training responses is a fitness-fatigue model. In the Banister s (1991) fitness-fatigue model the training is thought to result in 2 after-effects: fitness and fatigue. These effects can result either positive or negative outcomes. The fitness after-effect is a positive response and the fatigue after-effect is a negative response; the changes in performance are a summation of these responses. The duration of the fitness after-effects is longer than the duration of the fatigue after-effects, thus rest/recovery periods after an intensive training period may allow fatigue to drop without impairing the fitness results. (Chiu & Barnes 2003.) As seen in figure 9 the after-effects are strongly related to changes in performance. If the fitness after-effect is higher than fatigue after-effect, the performance improves and vice versa. It is important to remember that training has always a delayed training effect, i.e. the 19

25 positive or negative outcome of the training period is not observed immediately. A stressful training period may lead to high fitness and fatigue after-effects. Fatigue may mask the real performance level during a stressful training period. When a stressful training period is followed by a deload period the fatigue after-effects are removed and the fitness after-effects and the real performance level are observed. (Chiu & Barnes 2003.) FIGURE 9. Fitness-fatigue theory. (Chiu & Barnes 2003.) Busso et al. (1990) noticed that the fitness-fatigue model, also known as the system model, was an effective method for modelling the relationship between training and performance in elite weightlifters as the predicted and actual performance levels correlated strongly. Testosterone, T/C ratio and SHBG levels were also related to the calculated performance level. Regarding to these results, this model may be suitable for predicting the outcomes of strength training. (Busso et al ) 3.3 Overreaching and overtraining Short-term overloading is generally used in training programs to cause functional overreaching. Overreaching will be shown as a short-term reduction in performance capacity. A sufficient amount of rest should be provided to the body to recover from training-induced stress and to observe the gains in performance after the overreaching period. However, nonfunctional overreaching may also occur; if training is too demanding for a too long period of time it may lead to non-functional overreaching. If an adequate amount of rest is not provided 20

26 then, non-functional overreaching may be developed into overtraining. (Fry & Kreamer 1997, Kraemer & Häkkinen 2002 p , Bompa & Haff 2009 p. 100.) The overtraining syndrome may be developed, if training and life stressors accumulate until a too high extent. As a consequence, long-term decreasement in performance is observed. Overtraining has been related to many physiological and psychological symptoms such as disturbances in neural function, hormone concentrations, motor unit recruitment, muscle glycogen stores, immune function, resting heart rate and blood pressure, immune function, excitation-contraction coupling, mood and sleep patterns. Recovery from overtraining may take several weeks or even months. (Kraemer & Häkkinen 2002 p , Bompa & Haff 2009 p ) It has been noticed that different physiological responses occur at an overtraining state depending on the factor which has caused the state (table 4). If overtraining or overreaching state is caused by the increased strength training volume, the rest and acute testosterone concentrations and the T/C ratio will decrease and cortisol levels will increase. These changes indicate that the parasympathetic regulation is in dominating role when the overtraining state is caused by high volume. However, if the increased strength training intensity is the reason for overreaching or overtraining state, the acute and rest testosterone levels will not change or will be slightly elevated and the acute and rest cortisol levels will not change or will be slightly reduced. No changes in the T/C ratio has been observed. These changes indicate that the sympathetic regulation is in dominating role when the overtraining state is caused by high intensity. (Fry & Kraemer 1997.) 21

27 TABLE 4. Neuroendocrine responses to overreaching and overtraining caused by different factors. (Fry & Kraemer 1997.) Volek et al. (2003) noticed that the 4-week overreaching period increased cortisol and SHBG levels significantly whereas total testosterone, FAI and insulin levels decreased. Häkkinen et al. (1987) noticed that after a stressful 2-week training period the testosterone concentrations, the T/SHBG ratio and the T/C ratio decreased significantly in elite male weightlifters. The individual changes in the T/SHBG ratio correlated with the changes in clean&jerk results. The higher drop in the T/SHBG ratio was related to impaired clean&jerk performance. Coutts et al. (2007) noticed similar reductions in the T/C ratio as Häkkinen et al. (1987). During the 6- week progressive overload period the 3RM squat, 3RM bench press and max chin-ups strength decreased in rugby league players compared to previous measurements. As seen in table 5 there were also hormonal changes; cortisol levels increased, testosterone, the T/C ratio 22

28 and muscle glutamate were decreased and CK levels were increased during the overload period. (Coutts et al ) It seems that the T/C ratio may be a good marker for measuring overreaching and athlete s preparedness. The T/C ratio may decrease during an overreaching period which indicates a shift toward more catabolic state. A catabolic state is often related to decreased performance level. (Kraemer & Häkkinen 2002 p. 153.) TABLE 5. Changes in testosterone and cortisol levels and T/C ratio after a 6-week overload period. (Coutts et al ) Overtraining may also cause changes in the function of the neuromuscular system. Häkkinen & Komi (1983) noticed changes in maximal iemg of quadriceps muscles during the 16-week resistance training period. As shown in figure 10 maximal iemg values of vastus medialis and vastus lateralis muscles increased during the first 12 weeks of resistance training. After 12 weeks of training the iemg values of vastus lateralis (VL) and vastus medialis (VM) muscles started to decrease. This drop may be an indicator of overreaching and training induced fatigue. (Häkkinen 1994.) FIGURE 10. Changes in quadriceps iemg values during a 16-week resistance training programme. (Häkkinen & Komi 1983) 23

29 Coaches and researchers can monitor overreaching via different markers or tools. It might be beneficial to use subjective and objective markers to determine athlete s stress and performance levels, so the training can be appropriately adjusted. (Halson 2014.) 3.4 Detraining Detraining may occur, if training is ceased or an amount of the training is decreased. As a consequence, physiological and performance capacity decreases and training-induced adaptations will be lost. The rate of maladaptations will depend on several factors. The duration of the detraining period and athlete s training status will affect on the rate of maladaptations. (Kraemer & Häkkinen 2002 p , Bompa & Haff 2009 p ) The decrease in strength and power performances during a detraining period may be related to reductions in neural drive and Type II muscle fibres atrophy. (Bompa & Haff 2009 p. 159.) It is also possible that changes in the endocrine system may be related to performance reduction (Izquierdo et al. 2007). It has been noticed that in highly trained athletes the reductions in performance followed by a detraining period are higher than in untrained or recreationally trained individuals. Häkkinen et al. (1993) noticed that detraining may cause decreased maximal force in trained individuals. As seen in figure 11 the reduction in maximal force is higher in strength athletes than in recreationally trained men and women. However, individual differences were higher among strength athletes. (Häkkinen et al ) Izquierdo et al. (2007) noticed also that 4-week detraining period after the 16-week resistance training period led to significant reductions in maximal strength and muscle power output in strength-trained athletes. Reductions in muscle power output was between 14 and 17 % and reductions in maximal strength was approximately 6 % (Izquierdo et al ) Kraemer et al. (2002) obtained similar results than Häkkinen et al. (1993) in recreationally trained men. After a 6-week detraining period there were no significant changes in squat, shoulder and bench press 1RM strength in recreationally strength trained men. It seems that recreationally trained individuals do not loose strength significantly during a short detraining period. (Kraemer et al ) These studies are in line with the idea that detraining seems to effect differently on the performance in highly trained athletes and recreationally strength trained individuals. 24

30 FIGURE 11. Changes in maximal force during strength training and detraining. (Häkkinen et al ) Reduced maximal strength during and after the detraining period may be related to the changes in the neuromuscular system. Häkkinen et al. (1993) noticed decreased iemg values during a detraining period as seen in figure 12. The highest reduction seems to happen during the first 2-4 weeks of detraining but after that the changes plateaus. These decreased iemg values may result from maladaptation of the neural system. The neural system has adapted to strength training by enhanced neural activation and during the detraining period these adaptations may disappear. This reduced voluntary neural activation may result to decreased maximal strength. (Häkkinen et al ) 25

31 FIGURE 12. Mean iemgs of the vastus medialis (VM), vastus lateralis (VL) and rectus femoris (RF) muscles in isometric contraction during the heavy resistance training and detraining periods in previously untrained subjects. (Häkkinen et al ) Changes in muscle architecture may also occur during a detraining period. In Figure 13 the effects of resistance training and detraining on muscle fibre area and maximal strength in men are shown. During the resistance training period average muscle fibre area increases as well as muscular strength. During the detraining period muscle atrophy starts to occur as well as the reduction in muscular strength. The reduction in maximal strength levels is highest during the first 2-4 weeks of detraining and after this the reduction rate slows down. It seems that the decrease in muscular strength during the first weeks of detraining is mainly a result of decrease in maximal neural activation. After this first phase the further reductions may be related to muscle atrophy. (Häkkinen et al ) FIGURE 13. Average changes in muscle fibre area (A) and maximal bilateral leg extension strength (B) in male subjects during heavy resistance training and detraining periods. (Häkkinen et al ) 26

32 Despite the negative outcomes of long detraining periods, a short-term training cessation may be beneficial for performance. A short detraining period may allow body to recover and reduce the level of training induced fatigue. Pritchard et al. (2017) noticed that both 3.5 and 5.5 days off training after the 4-week resistance training period resulted to increased CMJ height and IBP relative peak force compared to pre-training values. This study demonstrates that short term training cessation may be beneficial for strength and power performances. Similar results were obtained in the study of Weiss et al. (2003). After an 8-week resistance training period subjects rested either 2, 3, 4 or 5 days. 1RM heel raise strength was significantly higher after 4 days of training cessation compared to 2 or 5 days (figure 14) and slow and fast eccentric only isokinetic strength improved slightly after 3 and 4 days of training cessation. FIGURE 14. 1RM heel raise strength after different duration of training abstinence. (Weiss et al ) 27

33 4 TAPERING Le Meur (2012) et al. and Mujika & Padilla (2003) are describing tapering as a progressive nonlinear reduction of the training load during the variable period of time, in an attempt to reduce the physiological and psychological stress of daily training and optimize sports performance. During an optimal tapering period accumulated fatigue decreases and body continues to adapt to a training stimulus which would contribute to enhanced performance. Body recovers, restores the tolerance to training and adapts to a given stimulus. (Mujika et al ) Mujika et all. (2003) noticed in their review paper that a tapering period can improve the performance approximately %. Typical performance improvements after a tapering period are between 2-3 %. (Mujika et al ) Mujika et al. (2002) noticed that the difference between the gold medallist and 4 th place in Sydney 2000 Olympic swimming competitions was 1.6 % and the difference between 3 rd and 8 th place was 2.0 %. It seems that taper induced gains in performance can make a difference between the winner and a loser. 4.1 Principles of tapering and manipulation of training variables Taper is the last part of the periodized training programme before the competition. The purpose of the taper is to prepare the athlete for the competition and get the peak performance out in a given day. (Mujika & Padilla 2003.) The competition calendar is the most important factor when periodizing training and planning out tapering periods (Bompa & Haff 2009 p ). Interaction between tapering and a preceding training period is one of the key factors for optimal performance (Pyne et al. 2009). For achieving the peak performance, common training variables will be manipulated during a tapering period. Training load will be reduced by decreasing volume, frequency or intensity of the training. The main goal is to reduce the accumulated fatigue but at the same time the positive training-induced anatomical, performance and physiological adaptations should not decrease. If the training load is reduced too much, detraining may occur and performance will be impaired. Therefore, the most important factor while planning the taper is to find a balance 28

34 between fatigue reduction and fitness maintenance/improvements. (Mujika & Padilla 2003.) It is also important to take non-physiological factors into account during the tapering period. Psychological factors influence onto the performance hence the holistic approach is needed for optimizing the outcomes of the taper. (Pyne et al ) Most of the coaches find the best tapering strategies via trial and error (Pyne et al. 2009). This was also observed in the study done by Ritchie et al. (2017) which interviewed Olympic coaches about their tapering practices. Most of the coaches reported to make the tapering plan according to experience, trial and error, literature and discussion with other coaches. (Ritchie et al ) Volume and intensity Bosquet et al. (2007) concluded in their review paper that improvements in performance seem to be more sensitive to reductions in training volume than for manipulation of other variables. They noticed that volume reduction during the tapering caused two times larger performance improvements than modifying the intensity or frequency. (Bosquet et al ) These conclusions are in line with the review of Pritchard et al. (2015a); a reduction in training volume resulted in better improvements in performance after a tapering period than the reduction in intensity. Few studies have noticed that a volume reduction can be an effective way to improve maximal strength. Häkkinen et al. (1991) noticed that maximal isometric force and maximal iemg values increased when the training volume was reduced 50 % in strength athletes. Gibala et al. (1994) got similar results in their study. Training volume was reduced linearly by decreasing the number of sets performed and the total volume reduction was 72 % over the tapering period. Maximal force increased compared to the pre-taper values and the percentage changes in performance during the taper are presented in the figure 15. Rhibi et al. (2016) noticed also that a 2-week reduced volume taper led to performance improvements after the 5- week resistance training period in non-trained men. Training volume was reduced linearly from session to session by reducing the amount of reps performed and the intensity was increased during the taper. After the tapering period significant improvements were observed 29

35 in 1RM half squat (26 %), squat jump (1.87 %) and countermovement jump (2.00 %). (Rhibi et al ) FIGURE 15. Changes in maximal force during reduced volume and rest only tapers. (Gibala et al ) For enhancing maximal strength, an appropriate reduction in training load seems to be between %, while intensity is remained at high levels (Pritchard et al. 2015a.) Positive performance responses in highly trained athletes have been observed with a volume reduction as high as %. (Mujika & Padilla 2003.) Bompa & Haff (2009 p. 191) concluded that % reduction in training volume results in optimal performance gains. It seems that an optimal performance may be achieved with different rates of volume reduction. When deciding the rate of the volume reduction it is important to take the duration of the taper into account as well as the previous training period. It may be that a higher volume reduction and a longer taper are needed when the pre-taper training load is heavy. (Bompa & Haff 2009 p ) Mehranpour et al. (2015) found out that 75 % reduction in training load during a 1-week taper was more effective than 50 % reduction in male wrestlers. Significant reductions of cortisol and IL-6 levels were observed in both groups relative to the control group. Reductions in cortisol and IL-6 levels were significantly higher in the 75 % group than in the 50 % group. The 75 % taper group showed also significant improvements in squat and bench press strength after a 1-week tapering period compared to the control group. (Mehranpour et 30

36 al ) It seems that high pre-taper training load requires higher reduction in training load during the taper. While the training load is decreased by reducing training volume, it is important to maintain the intensity at high levels. Maintaining or even increasing the intensity during the tapering period seems to help to maintain the feelings of power and speed, aerobic power and circulating anabolic hormones. It has also been noticed that training intensity is the most important factor to maintain training-induced adaptations during the periods of reduced training. (Mujika 2009 p. 74., Bompa & Haff 2009 p ) From a fitness-fatigue theory standpoint high-intensity training during a tapering period may increase the specific fitness after-effects and maximize the magnitude of fitness after-effects while the fatigue after-effect is decreased because of reduced training volume. (Chiu & Barnes 2003.) Zaras et al. (2014) noticed that using heavy loads (85 % of 1RM) instead of light loads (30 % of 1RM) during the tapering period led to higher improvements in strength and power variables in track and field athletes, but there was no difference in sport-specific performance improvements between the two groups. De Lacey et al. (2014) noticed also that a 21-day long taper period with a step wise volume reduction and maintained intensity resulted in likely-tovery-likely increases in maximum theoretical force and maximal power. These findings support the idea that using heavy loads and maintaining the intensity during the tapering period can lead to higher improvements in strength and power variables. (Zaras et al. 2014, De Lacey et al ) Duration of the taper and training frequency Different durations of the taper have been used and it is not well known yet where is the time point which separates the benefits of the taper from the negative outcomes of reduced training. Usually the length of taper is somewhere between 4 and 28 days. (Mujika & Padilla 2003.) In swimming, cycling and strength trained individuals the typical length of the taper is 2 weeks. (Mujika et al ) During the taper maintaining the training frequency at similar levels to pretaper values seems to be beneficial for performance in high level athletes. This allow the athletes to maintain the feel better. With moderately trained subjects the training 31

37 frequency can be lowered down to % from the pretaper value without losing performance or physiological adaptations. (Mujika 2009 p. 80., Mujika & Padilla 2003.) Bompa & Buzzichelli (2015 p.320) recommends that the taper macrocycle should not last more than three weeks so the detraining of the physiological systems will be avoided. On the other hand, large variability in the time point when the peak performance occurs during the taper has been observed between people (Mujika & Padilla 2003). The length of the taper is highly dependent from the type of the training preceding the taper. Higher training volume and/or intensity before the tapering period has been shown to lead to higher performance gains than no overloading. Sanchez et al. (2013) noticed that the overload training period allowed higher performance gains in elite female gymnasts compared to the non-overload period before tapering. When taper follows an overload period the longer duration may be needed to achieve performance enhancement. (Thomas & Busso 2005.) Coutts et al. (2007) noticed that the 1-week step taper with volume and intensity reduction led only to small increases in 3RM squat and bench press compared to pretaper values. It seems that a 1-week taper after a 6-week overreaching period in competitive rugby players was not long enough for full recovery and performance enhancements. (Coutts et al ) Chtourou et al. (2012) noticed that knee extensors maximal voluntary contraction increased significantly when a 12-week strength training period was followed by a 1- or 2-week tapering period. De Lacey et al (2014) noticed that 21-days long step taper after a prolonged preseason strength and conditioning programme improved maximal power output in professional rugby players. During the tapering period the volume was reduced but the intensity remained at high levels. (De Lacey et al ) Mehranpour et al. (2016) compared 1-week and 3-week tapers in male wrestlers. The authors noticed that IL-6 levels decreased in both groups after the taper. After a 1-week taper plasma cortisol levels decreased significantly and bench press and squat 1RMs increased significantly. The authors concluded that a 1-week taper with high volume reduction seems to be more effective than a 3-week taper. (Mehranpour et al ) It seems that tapers with different durations can be succesful and it is important to consider the preceding training period and athletes training age/status while planning the taper. 32

38 4.2 Mechanisms behind improved performance during and after a taper period There are several factors which impact on performance either positively or negatively. The factors can be divided into physiological and non-physiological factors. Physiological factors consist neuromuscular, hormonal, cardiorespiratory, metabolic and biochemical variables. Psychological states and psychophysiological functions (for example pain tolerance) are known as non-physiological factors. (Mujika et al ) Mechanisms which explain the improved maximal strength performance after the tapering period are not well known yet. Changes in the nervous system and at hormonal level may have a role in improved performance (Häkkinen et al , Häkkinen et al. 1987, Izquierdo et al. 2007, Coutts et al , Pritchard et al. 2015a.) Also changes in muscle mass and in muscle architecture may be potential factors behind improved performance (Pritchard et al. 2015a) Changes in hormone concentrations In previous studies it has been noticed that blood levels of creatine-kinase are usually reduced after a tapering period. CK levels are related to muscle damage and CK seems to reflect more on training volume than on intensity. (Mujika et al ) Also changes in testosterone, SHBG and cortisol levels have been observed after a tapering period. Increased testosterone and decreased cortisol levels can be signs of a sift towards to more anabolic environment inside the body. Häkkinen et al. (1987) noticed that during a normal 2-week and reduced 2-week training periods serum cortisol decreased significantly compared to the values after a stressful training period. The concentration of serum testosterone did not change but the T/SHBG ratio increased during these training phases as seen in figure 16. The individual changes in the T/SHBG ratio correlated significantly with the individual changes in clean&jerk result. A higher T/SHBG ratio was related to higher improvements in clean&jerk. These results suggest that improved hormonal profile can enhance the maximal strength and power performance. (Häkkinen et al ) 33

39 FIGURE 16. Relationships between total training volume, T/SHBG ratio and weightlifting result in male strength athletes. (Häkkinen et al ) Izquierdo et al. (2007) did a study with Basque ball players and noticed also positive changes in hormonal profile. The players performed the 16-week resistance training period followed by 4 weeks of tapering. In the tapering group (n=11) the training volume was reduced and intensity increased by a progressive manner. In this group the players trained with % of 1RM for 2-3 sets of 2-4 repetitions. The tapering group results were compared to the complete rest (n=14) and control groups (n=21). The taper group increased their 1RM bench press (2 %) and parallel squat (3 %) statistically significantly after a tapering period. Based on the results of this study it seems that a longer duration (4 weeks) progressive taper with lowered volume and increased intensity might improve performance in dynamic multijoint exercises. There were also changes at a hormonal level along with the improvements in performance. After the tapering period elevation in IGFBP-3 resting serum level was observed, while in the detraining group IGF-1 concentration was elevated. This finding seems to support the hypothesis that changes in the endocrine system may be related to taper induced strength improvements. (Izquierdo et al ) However, Coutts et al. (2007) noticed that the T/C ratio decreased significantly during the 6- week overload period in rugby players and it did not change after the tapering period. CK 34

40 levels were significantly increased after the training period and during the 7-day taper the levels decreased significantly. Based on the findings of this study it seems that enhanced muscle recovery was achieved during the taper, but hormonal profile did not change towards anabolic direction during a 7-day taper. It may be that for observing the changes at a hormonal level a longer duration of the taper is needed Changes in the neuromuscular system Changes in the function of the nervous system may also explain the enhanced maximal strength after a tapering period. Improved voluntary activation may be one factor behind improved strength performance. (Häkkinen et al ) Häkkinen et al. (1991) noticed that in strength athletes maximal isometric force and maximal iemg values increased during the tapering period as seen in figure 17. Increased quadriceps muscles iemg values may result from enhanced voluntary neural activation of the muscles. It seems that the tapering period can lead to increased level of muscle activation. (Häkkinen et al ) FIGURE 17. Relationship between maximal force, training volume and maximal iemg values in strength athletes. (Häkkinen et al ) Gibala et al. (1994) noticed that a 2-week tapering period after 3-week elbow flexor training led to improved performance. During the tapering period volume was decreased progressively from session to session and intensity was maintained at the same level. Total volume 35

41 reduction during the taper was 72 %. Isometric elbow flexor strength increased significantly in the taper group but there were no changes in the rest only group. The authors did not notice changes in motor unit activation rates measured by electrical stimulation. They concluded that this method may not be sensitive enough to capture the changes in the neural system. (Gibala et al ) Changes in body composition Zaras et al. (2014) did not observe any changes in vastus lateralis muscle architecture after the 2-week taper. However, they noticed that lean body mass gained during the training period was maintained during both, light and heavy load, tapers. It seems that gained muscle mass can be maintained during the taper, but further gains are not taking place. It may be that during a longer taper period gains in muscle mass and changes in muscle architecture could occur, but this has not been shown in scientific articles yet. 4.3 Tapering strategies in powerlifting Two studies based on interviews about powerlifters tapering strategies have been done. Pritchard et al. (2015b) interviewed 11 elite raw powerlifters from New-Zealand about their tapering strategies and Grgic & Mikulic (2017) investigated tapering strategies of Croatian open-class powerlifting champions. Pritchard et al. (2015b) noticed that the highest training volume was reached approximately 5.2 weeks before the competition and average training intensity peaked approximately 2 weeks before the competition. During the tapering period the reduction in training volume was about 58.9±8.4 % and intensity was maintained or slightly reduced. In Grgic and Mikulic (2017) study the mean volume reduction during the taper was 50.5±11.7 % and the intensity was maintained or increased during the tapering period. Taper length was approximately 2.4±0.9 weeks and the last training session was performed approximately 3.7±1.6 days before the competition. (Pritchard et al. 2015b.) Grgic & Mikulic (2017) did similar conclusions; taper length was 18±8 days and the last session was performed 3±1 day before the competition. In Pritchard s et al. (2015b) study the lifters reported that the volume reduction during the tapering period was mostly done by removing 36

42 the accessory work. Squat and deadlift accessory work was removed 2.0±0.7 weeks before the competition and bench accessory 1.9±07 weeks before the competition. 70 % of the lifters in Grgic & Mikulic (2017) study had removed the accessory exercises from their programme during the taper. Removing the accessory work allows more recovery for the body and training becomes competition focused and specific. (Pritchard et al. 2015b.) Pritchard et al. (2015b) reported that deadlift, squat and bench press followed different tapering strategies but 70 % of the lifters in the study of Grgic and Mikulic (2017) reported that all three lifts followed the same strategy. In the final week before the competition the training frequency was reduced approximately 47.9 ±17.5 % in Grgic and Mikulic (2017) study and approximately to 34.7±14.2 % in Pritchard s et al. (2015b) study. In table 6 the time points of last heavy training and last training sessions for each lift are shown. Grgic & Mikulic (2017) reported that the volume reduction followed either a step or fast decay exponential model. Pritchard et al. (2015b) did not ask which tapering model the lifters in their study followed. TABLE 6. Time points of last heavy and last training sessions performed. (modified from Pritchard et al. 2015b and Grgic & Mikulic 2017.) Final training session type Days out of competition Top set(s) % of 1RM (%) Final heavy squat session (>85 % of 1RM) Pritchard et al Grgic & Mikulic 2017 Pritchard et al Grgic & Mikulic ±2.9 7±1 90.0± ±3.2 Final squat session 4.0±1.8 4±2 66.0± ±19.9 Final heavy bench press session (>85 % of 1RM) Final bench press session Final heavy deadlift session (>85 % of 1RM) 7.3±2.7 6±2 92.2± ± ±1.8 3±1 67.3± ± ±4.0 8±2 88.9± ±3.6 Final deadlift session 7.4±4.1 4±3 72.6± ±

43 As a conclusion from these studies it seems that a typical volume reduction in powerlifting type training program during the tapering period is approximately 50 % while the intensity is maintained. The length of the taper varies between 2-3 weeks. (Pritchard et al. 2015b, Grgic & Mikulic 2017.) 38

44 5 TAPERING MODELS There are four different tapering models which are widely used. These models are step tapering, linear tapering and exponential tapering. In the exponential tapering the reduction in training load may follow either a slow or fast time constant of decay. (Mujika & Padilla 2003.) Schematic representation of all four tapering models is shown in figure 18. Linear and exponential tapers are known as progressive tapering strategies. In step tapering the volume reduction will be done once and then this reduced volume is maintained at the same level during the whole tapering period. The total training load used is the lowest in the step taper model when comparing to other tapering models. (Bompa & Buzzchelli 2015 p.321) In linear taper the training load is reduced progressively with a linear fashion. In exponential tapers the reduction in training load occurs either with a fast or slow time constant of decay. In slow decay model, the training load remains higher than in fast decay. (Pritchard et al. 2015a.) Usually while using these progressive tapering strategies the reduction in training load is smaller over a longer duration of time than in step taper. (Mujika 2009 p.7-9.) FIGURE 18. Tapering models. (Mujika & Padilla 2003.) 39

45 Thomas et al. (2008) assessed performance responses to different types of tapering models with computer simulation in elite swimmers. The authors noticed that both styles of tapers, step and progressive, can enhance performance. When an overload period was used before the taper a longer tapering period was needed for improved performance as shown in table 7. However, the performance peaked to a higher level when an overload period was used before the tapering period. The authors noticed also that when using a step taper the reduction in training load needed to be higher while comparing to linear and exponential tapers. (Thomas et al ) TABLE 7. Comparison of different tapering models for enhancing swimming performance with and without an overload training (OT). (Thomas et al ) Thomas & Busso (2005) did also mathematical modelling of different types of tapers. In their model high-intensity cycle ergometer training programme was followed by a taper. The authors noticed that a progressive reduction in training load allowed higher improvements in performance than a step-wise reduction when an overload period was used before a tapering period. (Thomas & Busso 2005.) Banister et al. (1999) did also a simulated comparison of different tapering models by using a systems model in triathlon athletes. In simulated situations exponential taper was superior compared to step-reduction taper and furthermore a fast-decay exponential was better than a slow-decay exponential. These results were tested experimentally after the simulation and the results from the experiment were in line with the results from the simulations. During the experiment the exponential taper group improved significantly more above the pre-taper standard than the step-taper group in cycle ergometry. 40

46 A fast-decay exponential taper group also improved more above the pre-taper value than a slow-decay exponential taper group. (Banister et al ) In table 8 studies using different tapering models to enhance maximal strength and/or power are presented. Based on the findings of these studies it seems that both step and progressive tapers seem to be beneficial while aiming to peak maximal strength and/or power. However, there is no research yet in which use of different tapering models for enhancing maximal strength would have been compared directly. TABLE 8. Effects of different types of tapers on maximal strength and power. STUDY SUBJECTS TAPER TYPE Häkkinen et al male powerlifters VOLUME REDUCTION LENGTH OF THE TAPER RESULTS step 50 % 1-week increased maximal force increased iemg values Gibala et al Coutts et al Izquierdo et al Chtourou et al De Lacey et al Rhibi et al recreationally strentgh trained men 7 male rugby players 11 male basque ball players 31 untrained men 7 professional male rugby players 28 untrained men progressive: linear 72 % 10-days increased elbow flexor MVIC step 55 % 1-week minimum clinically important improvements in 3RM squat, 3RM bench press and max chin-ups progressive? 4-weeks increased maximal strength (bench press, squat) step appr. 50 % 2-weeks improved squat jump, CMJ, MVC knee extension step 74 % 3-weeks improved maximal power ouput and jump height performance progressive: linear app. 30 % 2-weeks increased 1RM half squat, squat jump and CMJ Bazyler et al male throwers progressive: exponential? 3-weeks improved throwing performance, CMJFP 0 kg and CMJPP 0kg 41

47 6 RESEARCH QUESTIONS AND HYPOTHESES Purpose of the study: The purpose of this study was to find out how two different 2-week reduced volume tapering periods effects on maximal strength, hormonal concentrations and neuromuscular variables in recreationally strength trained men after an 8-week strength training period. Another purpose was to find out the mechanisms behind the changes in maximal strength during and after the taper. Research questions and hypotheses: 1. Will maximal strength increase during/after a tapering period? Hypothesis: Maximal strength will increase after a tapering period. It has been noticed that tapering or even training cessation for short period of time has led to improved maximal strength. (Häkkinen et al. 1991, Gibala et al. 1994, De Lacey et al , Zaras et al. 2014, Rhibi et al. 2016, Mujika & Padilla 2003.) 2. When is maximal strength at the highest level during the tapering period? Hypothesis: Maximal strength is at the highest level in the end of the taper. Training induced fatigue will decrease during the tapering period (Chiu & Barnes 2003, Mujika 2009 p.74, Bomba & Haff 2009 p ). However, it is not well known yet where is the time point which separates the benefits of the taper from the negative outcomes of reduced training (Mujika & Padilla 2003). The goal is to reach the peak at the end of the taper. 3. Is there a difference when the peak performance occurs between two differently performed reduced volume tapering periods? 42

48 Hypothesis: When the training volume is reduced differently the peak in performance may occur at different time points. The needed reduction in training volume and length of the taper are dependant of the state of fatigue and fitness and the volume used in the previous training cycles. It has been noticed that if an overreaching period is used before the taper, the length of the taper may need to be longer. (Thomas & Busso 2005, Mujika & Padilla 2003, Coutts et al. 2006, Sanchez et al ) 4. Will differently performed tapers cause different responses/changes in the neuromuscular and endocrine system? Hypothesis: When the volume reduction is performed in different ways, the neuromuscular and endocrine systems may respond differently. It has been noticed that body adapts to strength training at the neuromuscular, muscular and endocrine level (Häkkinen & Kraemer 2002, Bompa & Buzzichelli 2015, Bird et al. 2005). These adaptations and changes are related to the stimulus and it has been noticed that training volume and intensity affect onto the adaptations (Häkkinen & Kraemer, Häkkinen 1987, Häkkinen 1994). Regarding to these findings, it may be that when training volume is reduced in different ways the responses will be different. 5. What are the mechanisms behind changes in maximal strength during/after a tapering period? Hypothesis: The purpose of the taper is to reduce training induced fatigue and allow body to recover, so the real fitness level can be observed. Mechanisms behind improved performance are related to the changes in the neuromuscular and endocrine systems. There will be changes in the function of the neuromuscular system and endocrine responses when body is in a more recovered state. It is not well known yet why maximal strength increases during/after a tapering period. In previous studies it has been noticed that improvements may stem from changes in hormonal 43

49 concentrations and the nervous system (Häkkinen et al. 1987, Izquierdo et al. 2007, Coutts et al. 2007, Häkkinen et al. 1991). The improvements might be related to better recovery of the different systems and more anabolic environment inside the body (Mujika et al. 2004, Pritchard et al. 2015a). 44

50 7 METHODS 7.1 Subjects 21 recreationally resistance trained (at least 1-year of resistance training experience) men voluntarily participated in this study. Subjects were 25.9±2.6 years old, mean height and weight were 181.5±4.7 cm and 83.0±10.4 kg respectively. 14 subjects finished the study, 2 subjects dropped out because of injuries and 5 because of personal reasons. All 14 subjects followed the same strength training protocol for 8-weeks and after that they were divided into two groups (N=7) which both followed different tapering methods for two weeks. The subjects were 26.1±2.8 years old, mean height was 183.1±5.5 cm and mean weight was 84.2±11.2 kg in group 1 and 25.6±2.6 years old, 180.0±3.5 cm tall and 81.7±9.4 kg heavy in group 2. The study was approved by the Ethics Committees of the University of Jyväskylä. 7.2 Experimental design The study consisted a 1-week control period and an 8-week strength training period which was followed by the 2-week tapering period. The measurements were performed before the control period (control measurements) after the control period (pre measurements), after 5 weeks of strength training (mid measurements), after 8 weeks of strength training (post measurements), after 1 week of tapering (taper 1) and after 2 weeks of tapering (taper 2). Control period: During the control period subjects were informed to maintain their normal physical activity level and training schedule. The control measurements were performed before the control period. Training period: The training period started after the pre measurements. All the subjects trained with a similar manner 3x/week for the first 8 weeks. After 5 weeks of training the mid measurements were performed. After 8 weeks of training the post-measurements were performed. 45

51 Tapering period: After the post measurements subjects were randomly divided into 2 different tapering groups. Both groups trained 2x/week during the taper, but the reduction in the training volume differed as follows: group 1 followed a step-wise taper model and the plan was to reduce the volume by about 50 % from the pre taper value and train the two taper weeks with the same volume. The actual volume reduction in group 1 was precisely 54 %. Group 2 followed an exponential taper model. During the 1 st taper week the plan was to reduce the training volume about 25 % from the pre taper value. The actual reduction in the training volume was 42 % in group 2 during the 1 st tapering week. For the 2 nd tapering week the plan was to reduce the training load by about 75 % and the actual reduction was 66 % from the pre taper value. In both groups training intensity was remained at the pre taper level and the overall final reduction in the training volume was the same (54 %) in both groups. 7.3 Training program Subjects did strength training 3 times/week during the 8-week training period. The exercises used during the 1 st phase of the training program are presented in table % of the training sessions were supervised. Subjects were allowed to do training sessions by themselves when they were not able to come to the supervised sessions because of personal reasons. TABLE 9. Exercised used during the phase 1 (weeks 1-5). DAY 1 DAY 2 DAY 3 squat leg press squat bench press overhead press bench press row knee extension row side plank leg curl back extension lat pull-down plank Reps and sets are presented in figure 19. During the 1st training phase sets and reps in squat and bench press were 5x5. The load was increased from week to week and the week mean intensity is presented in figure 19. In the first training session 5 RMs were determined for the squat and bench press and these numbers were used to determine the loads for the following sessions. In the other exercises the load was determined with the RPE/RIR (reps in reserve) scale. 46

52 Week 1 Day 1: measurements Day 2: measurements Day 3: 1st training session, detemining 5 RMs in squat and bench press Day 4: 2nd training session (day 2 exercises): : leg press 8, knee extension 8, overhead press RPE 8 Week 2 Day 1: 5x5 constant load Day 2: leg press 8, knee extension 8, overhead press RPE 8 Day 3: 5x5 progressive load Mean intensity: % Week 3 Day 1: 5x5 constant load Day 2: leg press 9, knee extension 8, overhead press RPE 9 Day 3: 5x5 progressive load Mean intensity: % Week 4 Day 1: 5x5 constant load Day 2: leg press 9, knee extension 8, overhead press 8 Day 3: 5x5 progressive load Mean intensity: % Week 5 Day 1: 5x5 constant load (appr. 86 %) Day 2: leg press 9, knee extension 8, overhead press 8 Day 3: light session, 3x5 progressive load, mean int. 60 % FIGURE 19. The 1st training phase (weeks 1-5). After the 1 st training phase the mid measurements were performed. After the measurements subjects started the 2 nd training phase (weeks 6-8). The exercises of the 2 nd phase are presented in table 10. TABLE 10. Exercises during the phase 2 (weeks 6-8). DAY 1 DAY 2 DAY 3 squat squat squat bench press bench press bench press row knee extension leg press back extension leg curl row plank overhead press side plank lat pull-down Training protocol during the 2 nd phase is presented in figure 20. During the 1 st training session 5RMs in squat and bench press were determined and these numbers were used for determining the loads for the first and last sets for the following sessions. In other exercises loads were determined with the RPE/RIR scale. The RPE/RIR scale was also used to adjust 47

53 the loads in those squat and bench press sessions in which subjects performed triples and doubles. Week 6 Day 1: measurements Day 2: measurements Day 3: training, determining 5 RMs Day 4: 4x3 (75 %, 80 %, 82.5 %, 87.5 %) Week 7 Day 1: 5x3: goal was to do one set with 3RM load (RPE 9 or over) Day 2: 3x5 (70 %, 75 %, 80 %) Day 3: 5x2 : goal was to do one set with 2 RM load (RPE 9 or over) Week 8 Day 1: 6x3: goal was to do one set with 3RM load (RPE 9 or over) Day 2: 3x5 (70 %, 75 %, 80 %) Day 3: 6x2: goal was to do one set with 3RM load (RPE 9 or over) FIGURE 20. Training protocol during the 2 nd training phase (weeks 6-8). The post measurements were performed after the 2 nd training phase and after these subjects were divided into two groups which followed different tapering protocols. The reduction in the training volume was based on repetitions and sets performed on the last training week (week 8). Group 1 followed the step-wise reduction in their training volume and trained both taper weeks with the 46 % volume of the pre taper value. Group 2 followed an exponential reduction in their training volume and trained the 1st week with the 58 % volume of the pre taper value and the 2nd week with the 34 % of the pre taper value. The highest loads during the tapering were 2.5 kg below the highest load used for three repetitions in squat and bench press during the last training session performed in week 8. This 2.5 kg under the highest triple load was determined to be 90 % of 1RM. 1RMs for squat and bench press were determined from this number and the loads for other sets were calculated from this 1RM. The other loads used in work sets were 85 % and 87,5 %. Mean intensity was calculated from the percentages above and was 87 % in both groups in both weeks. Weight used in leg press was the average weight of the last two sets performed in week 8. Weight was 48

54 the same in every set and workout during tapering. The tapering protocols for week 1 and week 2 are presented in tables 11 and 12 respectively. TABLE 11. Taper week 1 DAY 1 DAY 2 Group 1 Group 2 DAY 3 Group 1 Group 2 measurements: squat 4x3 (85 %, 5x3 (85 %, 87.5 squat 4x2 (85 %, 87.5%, 90 %, 87.5%) %, 90 %, 87.5 %, 85 %) 87.5%, 90 %, 87.5%) leg press MVIC bench press 4x3 (85 %, 87.5%, 90 %, 87.5%) 5x3 (85 %, 87.5 %, 90 %, 87.5 %, 85 %) squat 1RM leg press 2x6 3x6 back extension bench press 1RM plank 2x3x20/10s 2x3x20/10s squat power bench press power bench press 4x2 (85 %, 87.5%, 90 %, 87.5%) 2x10 5x2 (85 %, 87.5 %, 90 %, 87.5 %, 85 %) 5x2(85 %, 87.5 %, 90 %, 87.5 %, 85 %) 2x10 TABLE 12. Taper week 2 DAY 1 DAY 2 Group 1 Group 2 DAY 3 Group 1 Group 2 measurements: squat 4x3 (85 %, 3x3 (85 %, 90 squat 4x2 (85 %, 87.5%, 90 %, 87.5%) %, 85 %) 87.5%, 90 %, 87.5%) leg press MVIC bench press 4x3 (85 %, 87.5%, 90 %, 87.5%) 3x3 (85 %, 90 %, 85 %) squat power leg press 2x6 1x6 back extension bench press power plank 2x3x20/10s 2x3x20/10s bench press 4x2 (85 %, 87.5%, 90 %, 87.5%) 2x10 3x2 (85 %, 90 %, 85 %) 3x2 (85 %, 90 %, 85 %) 2x10 The relative training volume, reduction in training volume and reps performed during both tapering weeks are presented in table 13. Volume calculations were based on the training volume of week 8. 49

55 TABLE 13. Training volume manipulation during the tapering period. Variable Taper wk 1 Taper wk 2 Overall Squat Bench Leg Lower Upper Squat Bench Leg Lower Upper Squat Press Press Body Body Press Press Body Body Training volume Group 1 46 % 46 % 51 % 45 % 38 % 46 % 46 % 51 % 45 % 38 % 46 % 46 % 51 % 45 % 38 % (%) Group 2 58 % 56 % 77 % 61 % 48 % 34 % 34 % 26 % 28 % 29 % 46 % 45 % 52 % 45 % 38 % Reduction (%) Group 1 54 % 54 % 49 % 55 % 62 % 54 % 54 % 49 % 55 % 62 % 54 % 54 % 49 % 55 % 62 % Group 2 42 % 44 % 23 % 38 % 52 % 66 % 66 % 74 % 72 % 71 % 54 % 55 % 48 % 55 % 62 % Reps performed Group Group Bench Press Leg Press Lower Body Upper Body 50

56 7.4 Data collection and analyses Timetable of the measurements and measurement instructions The control tests were performed in the beginning of the control period (week -1), pre measurements in the beginning of the training period (week 0), mid measurements after 5 weeks of training (week 5), post measurements after 8 weeks of training (week 8), taper 1 measurements after 1 week of tapering (taper week 1) and taper 2 measurements after 2 weeks of tapering (taper week 2). Maximal isometric leg press and hormonal concentrations were measured six times during the research period (control, pre, mid, post, taper 1, taper 2). Squat and bench press 1RMs were measured five times during the experimental period (control, pre, mid, post, taper 2). Body composition and cross-sectional area of vastus lateralis muscle were measured four times during the research (control, pre, post and taper 2). Squat and bench press 1 RMs, leg press MVIC, CSA of vastus lateralis and hormonal concentrations were measured in the same day. Blood samples were taken in the morning of day 1 between 6:30 and 10:00. After the blood samples the body composition was measured. In the afternoon/evening between 12:00 and 21:00 of day 1 the strength measurements (leg press MVIC, squat and bench press 1RMs, squat and bench press power) were performed. The strength measurements were always performed in the following order: leg press MVIC, squat 1RM, bench press 1RM, squat power and bench press power. Subjects were informed to follow their regular diet during the control, training and tapering periods. All the testing sessions were performed 2 days after the last training session of a given period. Subjects were informed to avoid caffeine before the measurements. Body composition and blood samples were measured after a 12-hour fast Neuromuscular performance Isometric performance Bilateral leg extension. Maximal isometric bilateral horizontal leg extension force was measured on an electromechanical dynamometer (Department of Biology of Physical 51

57 Activity, University of Jyväskylä Finland, figure 21) with a knee angle of 107. Subjects were instructed to push as fast and hard as possible and maintain the maximum force as long as they were asked to relax (approximately 3-5 seconds). At least 3 maximal contractions were performed with a 1-minute rest between contractions. If the force increased more than 5 % on the last attempt an extra attempt was performed. All the contractions were sampled at 2000 Hz and filtered by a 10 Hz low-pass (4th order Butterworth) filter. Force data was analyzed with a customized script (Signal 4.04, CED, UK). FIGURE 21. Isometric leg press device Dynamic performance Squat 1-repetition maximum (1RM). Back squat 1RM was measured in the Smith-machine (figure 22). The subjects selected the stance width and bar placement by themselves during the control measurements. The chosen stance width was written down and this width was used in the following measurement sessions. Subjects were instructed to descend until their femur was parallel to the floor. An elastic band was set to the requested height to control the 52

58 depth. One of the researchers supervised that the desired depth was achieved and gave an up command when the subject had reached the correct depth. The repetition was successful when the subject was able fully extend the hips and knees. 1RMs were found within 3-5 attempts in every testing session and 3-minute rest was provided between each attempt. FIGURE 22. Smith-machine. Bench press 1-repetition maximum (1RM). Bench press 1RM was measured with free weights (figure 23). The subjects self-selected the grip width during the control measurements and this same width was used in the following measurement sessions. Subjects were instructed to lay supine on the bench and keep their head, buttocks and feet on the bench. Subjects were instructed to pause the bar on the chest and when the bar was paused on the chest one of the researchers gave the up command. The lift was successful if the subject was able to fully extend his arms. All 1RMs were found within 3-5 attempts in every testing session and a 3- minute rest was provided between each attempt. 53

59 FIGURE 23. Bench press setup Muscle activity measurements Surface electromyography. Bipolar electrodes were positioned on the vastus lateralis (VL) and vastus medialis (VM) of the right leg after shaving and abrasion of skin. The placement of the electrodes followed the SENIAM guidelines. Before the control measurements the correct spots were tattooed onto the skin with black ink. EMG was measured during the isometric bilateral leg press. Signal 4.04 software (Cambridge Electronic Design, UK) was used for recording. Telemyo 2400R, Noraxon, Scottsdale, USA and Model 16-2, EISA, Freiburg, Germany were used as signal receivers. The sampling frequency was 2000 Hz. EMG data was analysed with customised script (Signal 4.04, CED, UK). Average EMG (aemg) during ms and ms were analysed from both muscles Body composition and muscle mass measurements Bioelectrical impedance. Weight, fat free muscle mass, skeletal muscle mass, fat mass and body fat percentage were measured by an eight-polar bioelectrical impedance device (InBody 54