International Journal of Sports Physiology and Performance. The validity of session-rpe method for quantifying training load in water polo.

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1 International Journal of Sports Physiology and Performance The validity of session-rpe method for quantifying training load in water polo. Journal: International Journal of Sports Physiology and Performance Manuscript ID: IJSPP_2013_0297.R1 Manuscript Type: Original Investigation Keywords: coaching, training

2 Page 1 of 23 International Journal of Sports Physiology and Performance Università degli Studi di Torino DIPARTIMENTO DI SCIENZE MEDICHE Direttore: Prof. Franco Veglio Vice-Direttore alla Ricerca e Vicario: Vice-Direttore alla Didattica: Coordinatore EP Prof.ssa Anna Sapino Prof. Francesco Giuseppe De Rosa Dott.ssa Maria Grazia Santoiemma Responsabile Servizi Amm.vo/Contabili: Sig.ra Mariella Pautasso Corrado Lupo, Ph.D. Department of Medical Sciences; University of Turin, Turin, Italy. Tel. (Int.+3906) Fax. (Int.+3906) corrado.lupo@unito.it Prof. Carl Foster, PhD Editor of the International Journal of Sport Physiology and Performance Department of Exercise and Sport Science 133 Mitchell Hall University of Wisconsin La Crosse La Crosse, WI Phone: cfoster@uwlax.edu Turin, Italy, July 8, 2013 To the Editor of the International Journal of Sports Physiology and Performance Dear Editor, The undersigned authors transfer the ownership of copyright to the journal International Journal of Sports Physiology and Performance should their work be published in this journal. They state that the article The validity of session-rpe method for quantifying training load in water polo is original, has not been submitted for publication in other journals and has not yet been published either wholly or in part. They state that they are responsible for the research that they have designed and carried out; that they have participated in drafting and revising the manuscript submitted, whose contents they approve. In the case of studies carried out on human beings, the authors confirm that the study was approved by the ethics committee and that the subjects gave their informed consent. They also state that the research reported in the paper was undertaken in compliance with the Helsinki Declaration. Best regards, Corrado Lupo Human Kinetics, Corso 1607 Dogliotti N Market St, Champaign, Torino IL Segreteria: Tel: , Fax: segr.dsm@unito.it P.I C.F

3 International Journal of Sports Physiology and Performance Page 2 of 23 Università degli Studi di Torino DIPARTIMENTO DI SCIENZE MEDICHE Direttore: Prof. Franco Veglio Vice-Direttore alla Ricerca e Vicario: Vice-Direttore alla Didattica: Coordinatore EP Prof.ssa Anna Sapino Prof. Francesco Giuseppe De Rosa Dott.ssa Maria Grazia Santoiemma Responsabile Servizi Amm.vo/Contabili: Sig.ra Mariella Pautasso Laura Capranica Antonio Tessitore DECLARATION OF CONFLICTS OF INTEREST The authors state: they have no conflicts of interest o they have conflicts of interest (see below and in the MS file). Corrado Lupo Laura Capranica Antonio Tessitore Human Kinetics, Corso 1607 Dogliotti N Market St, Champaign, Torino IL Segreteria: Tel: , Fax: segr.dsm@unito.it P.I C.F

4 Page 3 of 23 International Journal of Sports Physiology and Performance Title of the Article: The validity of session-rpe method for quantifying training load in water polo. 2. Submission Type. Original Investigation. 3. a) name: Corrado; surname: Lupo; Institutional/Corporate Affiliations: SUISM, Research Center of Motor Sciences; Department of Medical Sciences; University of Turin, Turin, Italy. b) name: Laura; surname: Capranica; Institutional/Corporate Affiliations: Department of Human Movements and Sport Sciences; University of Rome Foro Italico, Rome, Italy. 8 b) name: Antonio; surname: Tessitore; Institutional/Corporate Affiliations: Department of Human Movements and Sport Sciences; University of Rome Foro Italico, Rome, Italy. 4. Contact Details for the Corresponding Author. Corrado Lupo; SUISM, Research Center of Motor Sciences; Department of Medical Sciences; University of Turin, Piazza Bernini, 12, Turin, Italy. telephone: Fax: corrado.lupo@unito.it 5. Preferred Running Head: 6. Abstract Word Count: Text-Only Word Count: Number of Figures and Tables: 4 and

5 International Journal of Sports Physiology and Performance Page 4 of The validity of session-rpe method for quantifying training load in water polo. Abstract Purpose: The assessment of internal training load (ITL) using the session rate of perceived exertion (session-rpe) has been demonstrated to provide valuable information, also in team sports. Nevertheless, no studies investigated the use of this method during youth water polo training. Thus, the aim of this study was to evaluate youth water polo training, showing the correspondent level of reliability of the session-rpe method. Methods: Thirteen male youth water polo players 29 (age, 15.6 ± 0.5 y; stature, 1.80 ± 0.06 m; body mass, 72.7 ± 7.8 kg) were monitored during training sessions (80 individual training sessions) within 10-days. The Edwards summated heart rate zone method was used as a reference measure of internal training load; the session-rpe rating was obtained using CR-10 scale modified by Foster. The Pearson product-moment was applied to regress the Edwards heart rate zone method against CR-10 session-rpe for each training session and individual data. Results: Analyses reported overall high (r=0.88; R 2 =0.78) and significant (P<0.001) correlations between Edwards s heart rate and session-rpe methods. Significant correlations were also shown for each training session (r range: ; R 2 range: , P<0.05) and individual data (r range: ; R 2 range: , P<0.05). Discussion: The present results confirmed the session-rpe method as an easy and reliable tool to evaluate ITL in youth water polo, allowing coaches to efficiently monitor their training plans Key Words: rating of perceived exertion, heart rate, internal training load, team sports, monitoring training 43 2

6 Page 5 of 23 International Journal of Sports Physiology and Performance Introduction To evaluate the success of training, coaches need to systematically monitor the internal training load (ITL). In particular, a proper monitoring of ITL will allow the coaches to be aware about the effectiveness of the training stimuli in provision of a successive training planning. However, in team sports, the act to monitor ITL is highly complex because of the individual characteristics of athletes and the frequent organization of workout in small groups. As team sports, the situational nature of water polo makes difficult to interpret the actual 51 physiological, technical and tactical, and psychological performance game profiles. In addition, the particular environment and the frequent dueling phases of this sport limit the monitoring of ITL. Anyhow, same studies were focused on the technical and technical aspects of game 1-6, as well as performance parameters (i.e., heart rate, blood lactate, and time of swimming) during tests and training in male 7 and female 8 elite, and youth 9 players. Regularly, in water polo, training programs are planned according to the external training load parameters (i.e., type and bouts of swimming and technical activity repetitions, total duration of specific exercises or entire training sessions, swimming distances). Usually, elite water polo players train up to nine 120-min units per week, excluding strength training sessions performed in a gym, which may vary from two to five sessions per week 1, while youth players perform from a minimum of four 90-min units per week with Under13 players 4 to a maximum of six 120-min units (including two strength training sessions) with Under 20 players. Therefore, as a consequence, each player could experience an individual physiological stress, during the performance of specific training programs (potentially occurring for different playing roles) as well as during group workouts. Thus, a practical and effective method that can properly monitor the ITL emerges as necessary to optimize the athlete s performance 10, and to limit the risk of overreaching, and burnout 11. To systematically monitor training, some authors 10 used the athlete s heart rate responses expressed as a percentage of individual maximal heart rate. However, considering that heart rate 3

7 International Journal of Sports Physiology and Performance Page 6 of reductions occur when the individual is immersed in water in an upright 12, or in a supine position 13, the intensity of exercise of water players calculated by heart rate recordings could be underestimated, making the monitoring of this performance more complex than that of other team sports played on ground. Based on the understanding that athletes can naturally monitor the physiological stress that their body experiences during exercise, subjective ratings of perceived exertion (RPE) have been assessed using category-ratio 14,15. In particular, several authors successfully verified the 77 quantification of ITL by multiplying the athlete s RPE for the total duration (minutes) of the training session (session-rpe) in steady state 16 and non-steady state 15 exercises, in endurance sports 17, as well as in swimming 18, and technical sports 19, while in team sports it has been focused on male 20,21 female 22 soccer players, and male basketball 23 players. Even though RPE has been already used with male elite 24 water polo players, these studies exclusively aimed to quantify specific swimming tests and decision making tasks, respectively, supporting the HR and blood lactate values. Therefore, no study has validated the session-rpe method to quantify the ITL in water polo. In addition, considering the high complexity of youth sports 25, the use of session-rpe method to quantify the ITL appears more needful for the young than adult players. Thus, the present study aimed to evaluate whether the session-rpe measured with the modified CR-10 Borg s scale 14 is a valid methods to monitor ITLs in youth water polo. In particular, it has been hypothesized that significant correlations would emerge between Session- RPE and Edwards heart rate-based methods, considering both team and individual data. Methods Design Recognized as a valid method to evaluate exercise intensity 26, the heart rate based method suggested by Edwards 27 was used as a reference of measure 15,28,29 to test the validity of session-rpe to quantify ITL in water polo. In particular, the Edwards method identified an individual ITL score by measuring the product of the accumulated training duration (minutes) of 5 HR zones by a 4

8 Page 7 of 23 International Journal of Sports Physiology and Performance coefficient relative to each zone (50 60% of HRmax = 1, 60 70% of HRmax = 2, 70 80% of HRmax = 3, 80 90% of HRmax = 4, % of HRmax = 5) and then summating the results. The percentages of the athlete s maximal heart rate is expressed by an estimation (220-age). To establish the youth water polo players perceived exertion (RPE), the Italian translation of the CR-10 scale 14 modified by Foster et al. 29 was used. In particular, the CR-10 RPE scale is a category-ratio scale characterized by scores and verbal links (i.e. from rest to maximal ), which translates the athlete s perception of efforts into a numerical score between 0 and 10 (Figure 1) Figure 1 here To avoid any potential interference by the competition results, the experimental sessions were organized during eight consecutively training sessions (i.e., from Monday to Friday of a previous week, and from Monday to Wednesday of the following one) during the pre-season period (i.e., 1 month before the beginning of the Italian National Under 17 Water Polo Championship) Furthermore, to provide ecological conditions during the experimental sessions, the team s coach freely planned different number of bouts and category of workout (i.e., swimming, individual skills, team tactical training, friendly match) without any attempt of manipulation by the experimental staff. Subjects The institutional review board of the University of Rome Foro Italico approved the collection of heart rate and RPE data during eight youth water polo training sessions. In addition, written information of the potential risks and benefits associated with participation, as well as oral instructions, were provided to one or both parents of each player. Successively, an informed consent form has been signed by one parent of each participant to the study. Thirteen youth male water polo players (age, 15.6 ± 0.5 y; stature, 1.80 ± 0.06 m; body mass, 72.7 ± 7.8 kg) took part to the study. The athletes had to fulfill the following inclusion 5

9 International Journal of Sports Physiology and Performance Page 8 of criteria: 1) compete at the Italian National Under 17 Water Polo Championship; 2) have at least 5 years of water polo training experience (consisting in a minimum of five to a maximum of eight min training weekly sessions). In particular, all subjects involved in this study could be considered elite level athletes, having been part of a team ranked second at the previous Italian National Under 17 Water Polo Championship. Methodology Heart rate was recorded every 5 s periods using a heart rate monitor (with a transmitter belt placed 129 on the water polo players chest before each training session) with internal memory (Team System, Polar, Kempele, Finland), which did not interfere with other electromagnetic systems and provided reliable data in water 4. The time of each individual training session was recorded to successively recognize the heart rate actually corresponding to the training activity. Therefore, the data stored in the belt were downloaded onto a computer using the specific software (Polar Precision software version 4, Kempele, Finland). Finally, heart rate data were classified according to the Edwards method to establish individual ITLs. One week prior to the start of the experimental period, the athletes were familiarized with the CR-10 scale, dominating the overall rating of the subject towards the end of the training session. Water polo players were asked to rate the intensity of their training about 30 min after each experimental session. Hence the individual CR-10 session-rpe scores were recorded and multiplied for the related duration (minutes) of the training sessions 15. Statistical Analysis Data were presented as mean values, standard deviations, and ranges. Statistical significance was set at an alpha level of P<0.05. The distribution of frequency (class of intensity: <50%, 50-60%, 60-70%, 70-80%, 80-90%, % of maximal heart rate) of the heart rate data recorded during all training sessions were presented as mean values and standard deviations. The statistical package SPSS (version 17.0) was used for the analysis. 6

10 Page 9 of 23 International Journal of Sports Physiology and Performance The relationship between the two methods to evaluate ITL was considered by means of the Pearson product-moment as well as the coefficient of determination (i.e., r = coefficient and R 2 = coefficient of determination). In particular, Edwards heart rate zone method was regressed against CR-10 session RPE for each training session and for each subject. Results Data related to the Edwards summated heart rate zone and session-rpe method determined an amount of 80 individual training sessions. The 13 individual correlations were determined by a 154 minimum of 5 to a maximum 8 training sessions. The mean duration of the 8 training sessions was :47:18±0:15:26 (h:min:s). Heart rate data of all training sessions were reported in figure Figure 2 here The mean RPE score of all individual training sessions was 6.5±2.0 (range: 2-10), while the team s mean RPE score of each single training session where reported in figure 3. High (r=0.88; R 2 =0.78) and significant (P<0.001) correlations between Edwards s heart rate and session-rpe methods emerged. Furthermore, figure 4 shows that session-rpe and Edwards ITL values correspondingly portray the team ITL during the 8 training sessions Figure 3 and 4 here Significant (P<0.05) correlations were also found for individual data (r range: ; R 2 range: ; Table 1), and single training sessions (r range: ; R 2 range: ; Table 2) Table 1 and 2 here Discussion 7

11 International Journal of Sports Physiology and Performance Page 10 of To our knowledge, this is the first study that has considered the Foster s RPE based approach 15,28,29 to quantify ITL in water polo, and to report significant correlations between this method and the Edwards heart rate-based one. In particular, the individual correlations (ranging from 0.76 to 0.98) found with our water polo players resulted in line with those reported for non-steady state 15 and steady state 16 exercise, technical sports 19, and overtraining syndrome 17, and swimming 18 athletes. In addition, the water polo individual correlations of this study reported equivalent or slightly higher values with respect to other team sports like men s 20 and women s soccer players 21, and men s 180 basketball 23. Therefore, based on our findings, the session-rpe method could be confirmed as a valuable tool to monitor different types of exercises 15 also in youth water polo. In particular, our results could promote the possibility to ecologically monitor water polo players, obviating to all impediments and limitations (i.e., water environment and dueling phases) related to a direct evaluation of the athletes ITL. To this regard, Impellizzeri et al. 20 claimed that the intermittent exercise nature of team sports (aerobic and anaerobic sources), could reduce the grade of correlations between session-rpe and Edward s heart rate based methods. However, the individual correlations found in this study showed satisfactory values and seems to not be negatively influenced by the typical water polo performance profile characterized by alternate intense bursts to low intensity intervals 30. Moreover, despite in our study each training session was characterized by heterogeneous portions of swimming, technical, and tactical exercises, the correlations of team session-rpe and team Edwards heart rate based resulted satisfactory, confirming the usefulness of RPE also for a general point of view. In fact, likely for individual correlation, the team values can effectively support the monitoring of training in relation to specific plans. Even though the present data were collected before the competitive period and there were not specific requests to favorite the recovery before and after the weekly match, the session-rpe values could support the identification of heavy training sessions and potential overtraining conditions. 8

12 Page 11 of 23 International Journal of Sports Physiology and Performance Several authors 31 claimed that in presence of particular training and competitive conditions, athletes tend to report lower RPE values than their actual heart rate responses. According to Casolino et al. 32, the discrepancy could be ascribed to the practice of closed and open skills, which lead athletes to experience high level of focus on the opponents actions and to perceive their effort as less demanding 31. Likely for the same reason, our youth water polo players showed high correlations for the swimming and individual skill training and less elevated values for team tactical training and friendly matches. It could infer that, during a tactical training and friendly matches, the 205 youth water polo players experience what they really prefer from a training session, feeling pleasure from practice, and therefore, underestimating their efforts. On the other hand, swimming and individual training could potentially stimulate players to more objectively estimate their efforts, avoiding the perception of any pleasant or negative sensation. Nevertheless, the Foster s RPE and the Edwards heart rate based approaches to quantify ITL in water polo showed largely satisfactory correlations for all training sessions, tactical practices and friendly matches included. In general, youth competition and training are doubtfully projected to an early specialization 25, determining a progressively necessity to regularly monitor the young athletes ITL. Therefore, also for this purpose, the present findings could be a valuable reference to promote the Session-RPE as useful tool for monitoring ITL in youth water polo training. Finally, in consideration that the present study was only focused on training sessions, further research should be promoted for the validity, reliability, and sensitivity of this method in relation to different seasonal periods (i.e., pre-season versus in-season). Moreover, this method should be investigated for men s and women s elite and sub-elite water polo players, clarifying any eventual influence derived by the competitive level. Practical Applications and Conclusions The current study highlights the effectiveness of the session-rpe to evaluate youth water polo training. Therefore, water polo coaches could benefit by the use of this method, because it does not require expensive equipments (i.e. telemetric heart rate systems) and may be very useful and 9

13 International Journal of Sports Physiology and Performance Page 12 of practical to monitor water polo players ITL. Moreover, monitoring ITL is fundamental to examine the effects of specific periodization strategies for the team in general as well as individually, minimizing the presence of injury, monotony and strain, and overreaching condition. Finally, the present data gathered satisfactory awareness on youth water polo players training condition, leading coaches to consider that swimming and individual skills could be more objectively perceived by water polo players than team tactical training and friendly match, probably due to the presence of weak and marked emotional influences, respectively

14 Page 13 of 23 International Journal of Sports Physiology and Performance Acknowledgments The authors would like to thank the coach Cosimino Di Cecca for his precious support

15 International Journal of Sports Physiology and Performance Page 14 of References Lupo C, Condello G, Capranica L, Tessitore Women's water polo World Championships: technical and tactical aspects of winning and losing teams in close and unbalanced games. J Strength Cond Res. 2013; Apr:Epub ahead of print. 2. Lupo C, Condello G, Tessitore A. Notational analysis of elite men s water polo related to specific margins of victory. J Sports Sci Med. 2012;11: Lupo C, Minganti C, Cortis C, Perroni F, Capranica L, Tessitore A. Effects of competition level on the centre forward role of men s water polo. J Sports Sci 2012;30(9): Lupo C, Tessitore A, Cortis C, Ammendolia A, Figura F, Capranica L. A physiological, time-motion, and technical comparison of youth water polo and Acquagoal. J Sports Sci. 2009;27(8): Lupo C, Tessitore A, Minganti C, Capranica L. Notational analysis of elite and sub-elite water polo matches. J Strength Cond Res. 2010;24(1): Lupo C, Tessitore A, Minganti C, King B, Cortis C, Capranica L. Notational analysis of American women's collegiate water polo matches. J Strength Cond Res. 2011; 25(3): Platanou T. Simple in-water vertical jump testing in water polo. Kinesiology. 2006;38(1): McCluskey L, Lynskey S, Kei Leung C, Woodhouse D, Briffa K, Hopper D. Throwing velocity and jump height in female water polo players: performance predictors. J Sci Med Sport. 2010;13(2): Falk B, Lidor R, Lander Y, Lang B. Talent identification and early development of elite water-polo players: a 2-year follow-up study. J Sports Sci. 2004;22(4): Mujika I. The influence of training characteristics and tapering on the adaptations in highly trained individuals: a review. Int J Sports Med. 1998;19:

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18 Page 17 of 23 International Journal of Sports Physiology and Performance 311 Figure captions Figure 1. Borg s CR-10 rating of perceived exertion modified by Foster (Foster et al. 1996) Figure 2. Distribution of frequency of the heart rate data recorded during all training sessions Figure 3. The mean team s values of RPE in the seven training sessions Figure 4. Session-RPE and Edwards TL values referred to the whole team (n = 13) during the 8 training sessions; AU, arbitrary unit

19 International Journal of Sports Physiology and Performance Page 18 of Table 1. Individual correlations between Session RPE and Edward s methods (r, R 2, and p values) Subjects r R 2 p S1 0,76 0,58 0,048 S2 0,86 0,74 0,029 S3 0,79 0,63 0,019 S4 0,99 0,97 0,014 S5 0,82 0,68 0,012 S6 0,96 0,91 0,001 S7 0,98 0,97 <0,001 S8 0,82 0,67 0,047 S9 0,83 0,69 0,042 S10 0,99 0,99 <0,001 S11 0,81 0,66 0,049 S12 0,98 0,95 0,024 S13 0,97 0,94 0,006 16

20 Page 19 of 23 International Journal of Sports Physiology and Performance Table 2. Team training sessions in relation to main category of workout and correlation between Session RPE and Edward s methods (r, R 2, and p values) Training session Day Main category of workout r R2 p 1st Monday individual technique 0,77 0,59 0,009 2nd Tuesday individual technique/team tactical 0,72 0,52 0,018 3rd Wednesday individual technique 0,74 0,54 0,015 4th Thursday team tactical 0,69 0,48 0,025 5th Friday friendly match 0,72 0,52 0,01 Saturday rest Sunday rest 6th Monday swimming 0,92 0,85 <0,001 7th Tuesday swimming/team tactical 0,81 0,66 0,004 8th Wednesday friendly match 0,70 0,49 0,024 17

21 International Journal of Sports Physiology and Performance Page 20 of Figure 1. Borg s CR-10 rating of perceived exertion modified by Foster (Foster et al. 1996) Rest 1 Very, Very Easy 2 Easy 3 Moderate 4 Somewhat Hard 5 Hard 6 7 Very Hard Maximal 18

22 Page 21 of 23 International Journal of Sports Physiology and Performance 333 Figure 2. Distribution of frequency of the heart rate data recorded during all training sessions Frequency of Occurrence (%) <50% 50-60% 60-70% 70-80% 80-90% % Class of intensity (%HRmax) 19

23 International Journal of Sports Physiology and Performance Page 22 of Figure 3. The mean team s values of RPE in the seven training sessions. RPE (Borg, CR-10) Monday Tuesday Wednesday Thursday Friday Saturday Sunday Training Sessions (S) Monday Twensday Wednesday

24 Page 23 of 23 International Journal of Sports Physiology and Performance Figure 4. Session-RPE and Edwards TL values referred to the whole team (n = 13) during the 8 training sessions; AU, arbitrary unit. Session-RPE Edwards'TL 341 Session-RPE (AU) Training sessions Edwards'TL (AU)