CORRELATION BETWEEN TIMED SIT UP TEST AND SIT UP TEST WITH NO TIME LIMIT WU SHING AN HONOURS PROJECT SUBMITTED IN PARTIAL FULFILMENT OF THE

Transcription

1 CORRELTION BETWEEN TIMED SIT UP TEST ND SIT UP TEST WITH NO TIME LIMIT BY WU SHING N HONOURS PROJECT SUBMITTED IN PRTIL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF BCHELOR OF RTS IN PHYSICL EDUCTION ND RECRETION MNGEMENT (HONOURS) HONG KONG BPTIST UNIVERSITY PRIL 2008

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3 2 HONG KONG BPTIST UNIVERSITY 25 th pril, 2008 We hereby recommend that the Honours Project by Mr. WU SHING entitled Correlation Between the Timed Sit-up Test and the Sit-up Test With No Time Limit be accepted in partial fulfillment of the requirements for the Bachelor of rts Honours Degree in Physical Education nd Recreation Management. Dr. Tong Kwok Keung Dr. Lau Wing Chung Chief dviser Second Reader

4 3 CKNOWLEDGEMENTS First of all, I would like to express my deepest gratitude to my chief advisor, Dr. Tong Kwok Keung, for his valuable advices and professional suggestions and guidance on the study. In addition, I would also like to express my gratitude to my second reader, Dr. Lau Wing Chung, to his effort on this study. On the other hand, I would also like to give thanks to P.E. teacher of Tai Po Government Secondary School, Ms. Siu Oi Yee, for her arrangement of the field tests. By the way, I would also like to express my appreciation to the students of Tai Po Government Secondary School for their participation in this study. Wu Shing Department of Physical Education Hong Kong Baptist University Date: 23 rd pril, 2008

5 4 BSTRCT Timed Sit-up Test is a very popular test for examining one s abdominal muscular endurance. However, according to the definition of muscular endurance, it is wondered if the limitation of time will affect the performance of the sit-up test. This study was designed to examine the validity of 1-minute sit-up test by assessing the correlation between the 1-minute sit-up result with that having no time limit. Seventy male and forty-five female students of Tai Po Government Secondary School were participated in the study (age, 14.8 ± 0.7 years; height, ± 8.2 cm; weight, 52.3 ± 8.2 kg). Subjects were asked to perform Timed Sit-up Test (Test 1) and Sit-up Test with no time limit (Test 2) respectively. Both tests performance were defined as repetition of sit-up performed. In this study, the mean of Test 1 and Test 2 was 38.1 ± 9.5 rep and 50.6 ± 17.1 rep respectively. It was found that there was a significant positive relationship between both tests (r = 0.709, p < 0.05), and the coefficient of

6 5 determination was 50.3% (r 2 = 0.503). ccording to the findings, it was suggested that the timed sit-up test was valid for examining one s abdominal muscle endurance.

7 6 TBLE OF CONTENTS CHPTER PGE 1. INTRODUCTION... 9 Statement of Problem Purpose of the Study Significance of the Study REVIEW OF LITERTURE Benefits of having good abdominal muscular endurance Timed Sit-up Test Various alternatives of abdominal exercises Factors affecting abdominal muscular endurance Summary of literature review Definition of Terms Research Hypothesis METHOD... 32

8 7 Subjects Procedures Delimitations Data nalysis Statistical Hypothesis Statistical nalysis Limitations RESULTS Discussion SUMMRY ND CONCLUSIONS Summary of Results Conclusion Recommendations of Further Study REFERENCES PPENDIX Data Collection Form B. Parental Consent Form... 55

9 8 LIST OF TBLES TBLE PGE 1. Physical characteristics of the subjects Descriptive statistics of the subjects performance in the Timed Sit-up Test and the Sit-up Test with no time limit Pearson s correlation test between the subjects performance in the Timed Sit-up Test and the Sit-up Test with no time limit... 40

10 9 Chapter 1 INTRODUCTION Muscular strength and endurance are one of the health-related physical fitness components (CSM, 2003). Franks (1989) also pointed out that certain amount of muscular strength and endurance was necessary to perform numerous daily tasks. In order to measure one s physical fitness level, many physical fitness tests were developed. Individual s physical fitness level would be interested for different bodies with different purposes. In Hong Kong, physical education of primary and secondary schools used School Physical Fitness ward Scheme as their protocols to determine students physical fitness levels; Security forces servants were necessary to pass a series of physical test before they were employed. In the above physical fitness tests batteries, timed sit-ups test had been included. The merican lliance for Health, Physical Education, Recreation and Dance (HPERD)

11 10 also put timed sit-ups into a four items test battery which evaluated physical fitness related to lifelong health (HPERD, 1976). They suggested that muscular strength and endurance was one of the important factors when considering one s physical fitness level. William, Stuart, ndre and William (1999) pointed out that abdominal muscle strengthening would contribute to performance enhancement, postural improvement and lowering the risk of low back pain. Timed Sit-up Test was one of the widely used methods which was developed to determine one s abdominal muscular strength and endurance. The test required subjects to perform maximal repetitions of sit-up in one minute. The more repetitions the subject has done, the higher marks he will get. Statement of problem Many longitudinal studies showed that abdominal muscles were recruited while sit-up was performed. Most studies of sit-up used electromyogram (EMG) to describe the movement dynamics. lthough hip flexor might be involved in performing

12 11 sit-ups of different styles, abdominal muscle recruitment must be involved (William et al., 1999; Carlos, Marco, Maria & Ricardo, 1991). For most previous EMG investigation, hip flexor s activity was not taken into consideration. Docherty (1996) defined that muscular endurance as the ability of a muscle, or muscle group, to generate force repeatedly or for an extended period of time. By looked at the definition briefly, limited time shall not be existed in a muscular endurance test. Once limited time was given in timed sit-ups test, speed of repetition of sit-ups would become an important factor with respect to his abdominal muscular endurance. It was wondered if the validity of 1 minute sit-up test was affected by the time limit. Purpose of Study The purpose of this study was to examine the validity of 1 minute sit-up test by assessing the correlation between the 1 minute sit-up result with that having no time limit.

13 12 Significance of the Study Similar to William et al. (1999), Gloria, Jorge, Danny, Matthew & Freddie (1997) stated that strong abdominal muscles played a very important role in both postural control and prevention of low back injury. In other words, abdominal muscular strength and endurance is important to human s health. Since individual s abdominal muscular strength and endurance is such important, relevant test protocols was developed to find out individual s abdominal muscular strength and endurance. Since timed sit-ups test was widely used, the test must be valid to measure individual s abdominal muscular strength and endurance. s muscular endurance means the ability of muscle to perform a muscle contraction repeatedly over a period of time, time shall not be taken into consideration. s a result, the validity of timed sit-ups test was queried. s aforesaid, abdominal muscular strength and endurance was vital to individuals. Physical educators needed to assess

14 13 students physical fitness levels in order to give them grades; Security forces servants needed to pass in the physical fitness test in order to prove their abilities to serve society. While the widely-used test protocol was not testing what it supposed to measure, all results from the test were said to be meaningless. In such case, individual s actual abdominal muscular strength and endurance would be hidden. This study is proposed to determine the correlation between the performance of timed sit-ups test and that of sit-ups with no time limit, to investigate whether one-minute sit-up test was valid to examine the one s abdominal muscular endurance.

15 14 Chapter 2 REVIEW OF LITERTURE Muscular endurance is important to our health. s described by Docherty (1996), muscular endurance is the ability of a muscle, or muscle group, to generate force repeatedly or for an extended period of time. Many sports and daily life body movement required certain level of muscular endurance. bdominal muscular endurance is especially important to maintain healthy body. Demont, Lephart, Giraldo, Giannantonio, Yuktanandana & Fu (1999) stated that strong abdominal musculature are considered important in both prevention and rehabilitation of lumbar pathologies. They also pointed out that several authors suggested that back pain was associated with weak abdominal muscles, and strengthening of abdominal muscles might be beneficial in reducing pain. The present study was to determine the correlation between the performance of timed sit-ups test and that of sit-ups with no time limit, to investigate whether one-minute sit-up test

16 15 was valid to examine the one s abdominal muscular endurance. The review of literature for the present study focused on the following aspects: (a) Benefits of having good abdominal muscular endurance; (b) Timed Sit-up Test; (c) Various alternatives of abdominal exercises; (d) Factors affecting abdominal muscular endurance; and (e) Summary of literature review. Benefits of having good abdominal muscular endurance bdominal muscular endurance is important to human s physical fitness. Demont et. l.(1999) pointed out that strong abdominal muscles are vital in both prevention and rehabilitation of lumbar pathologies. They added that low back pain is associated with weak abdominal muscles. Therefore, strengthening of abdominal muscles can be beneficial in reducing low back pain. In addition, Kasee and Larry (2004) stated that a minimal amount of abdominal endurance was necessary for maintaining proper alignment of the axial skeleton and supporting movements of both the lower and upprt

17 16 extremities in activities of daily living, work, and athletic performance. Similarly, Behm, Leonard, Young, Bonsey and MacKinnon (2005) also suggested that the strengthening of trunk muscles is an important consideration for activities of daily living, sports performance, and the rehabilitation of low back pain. mie and Mahyar (2007) had similar finding in their clinical research. They found that clinical trunk muscle endurance tests showed a relatively good sensitivity and specificity and predictive value in low back pain. Luoto et al. (1996) also suggested that psychomotor reaction time was faster in those subjects without back pain. part from above benefits, Tadashi, Noriyuki, Naotaka, Tomoyuki and Paul (1996) added that abdominal muscles had significant respiratory activity in humans. They pointed that the four abdominal muscle layers played an important role in compression of the abdominal contents, resulting in displacement of the diaphragm into the thorax and decrease

18 17 in lung volume. Timed Sit-up Test ccording to Teacher s Handbook of Physical Education School Physical Fitness ward Scheme (2007), the objective of the timed sit-up test was to measure the abdominal muscular strength and endurance by performing as many sit-ups as possible in one minute. The procedures of timed sit-up test were described as follow: The student lies on the mat with knees bent and the feet are held flat down firmly by a partner. The heels should be 30 to 45 cm from the buttocks, such that the angle between the thigh and the floor is about 45 degrees. rms are crossed in front of the chest with hands on the opposite shoulders. The chin is tucked to the chest. The student lies in supine position. In response to the starting signal, he/she curls up until the elbows touch the thighs, and then uncurls until the mid-back contacts the mat. This is counted as one time. The teacher should encourage the

19 18 student to repeat as many sit-ups as possible within one minute. The student may rest in a lying or sitting position during the test. Gail et al. (1992) stated that sit-up tests have been used in most youth and adult fitness test batteries because low back pain was always associated with abdominal strength. They suggested that timed sit-up tests had not been validated against a criterion measure to determine if they actually measure abdominal strength. Rather, power, average force, or torque was used to estimate strength. fter comparing the results of using Isokinetic dynamometer and that of performing timed sit-up tests, they found that there were significant differences. Various alternatives of abdominal exercises There were various alternatives of abdominal exercises other than sit-up. Some of them needed specific devices to help, such as b-roller ; some of them did not need, for example, curl-up. Many longitudinal studies had been done in

20 19 order to compare which abdominal exercise would recruit more muscle fibers and hence train the abdominal muscles more effectively. Carlos et al. (1991) had done a research to find out the contribution of the rectus abdominis and rectus femoris in twelve selected abdominal exercises. The abdominal exercises they chose were listed: (1) sit-up: long lying position without feet support, (2) sit-up: long lying position with feet supported, (3) sit-up: hook lying position with feet supported, (4) sit-up: hook lying position without feet supported, (5) curl-up, (6) elevation of lower limbs: forearm supported position, (7) elevation of lower limbs: long lying position, (8) V-sit, (9) conventional sit-up, (10) inclined sit-up: long lying position with feet supported and extended knee and hip (11) inclined sit-up: long lying position without feet supported flexed knee and hip, and (12) elevation of lower limbs: suspended position. fter electromyographic analysis, they discovered that V-sit was the most effective abdominal

21 20 exercise with respect to train upper rectus abdominis and lower rectus abdominis. Comparing with V-sit, sit-up: hook lying position with feet supported and flexed knee and hip had not significant difference with respect to upper rectus abdominis. However, they found that sit-up with feet supported was significantly lower muscle action potentials than V-sit with respect to lower rectus abdominis. Similar research finding was done by Walters and Partridge (1957). They generalized that sit-ups, curl-ups and V-sit were the most efficient exercises for abdominal muscles. In addition, they reported that less activity of abdominal muscles in sit-up exercises when feet were supported than when feet were unsupported. Some abdominal exercises could be helped by using devices. Manufacturers of the devices usually suggested that by using those devices there would be improvements in muscle strength while simultaneously protecting the back and neck. Demont et al. (1999) had done a study to compare the training effects

22 21 of the b-flex, b-roller and standard crunch on electromyogram production, isometric maximum voluntary contraction and Isokinetic average peak torque at 30 /sec of the abdominal muscles. They found that using those devices did not add significantly to overall abdominal strength development or reduction of body fat. Similar results were suggested by Kasee and Larry (2004). In their study, the suface electromyographic activity of the abdominal musculature and rectus femoris muscle during trunk-flexion, the traditional trunk curl and exercises using b-roller, b-slide and Fit Ball were compared. Similarly, they found that those devices did not elicit greater activity of the upper rectus abdominis and lower rectus abdominis than performing traditional trunk curls. On the other hand, they found that use of the b-slide elicited greater external oblique activity and significantly less upper rectus abdominis activity than the other 3 modes. Bird, Fletcher and Koch (2006) also compared the b-slide with crunch abdominal exercises for electromyographic activity for

23 22 abdominal muscles. They found that the external oblique and lower rectus abdominis had significantly higher integrated activation amplitudes for the crunch exercise during concentric movement. In contrary, the upper rectus abdominis, lower rectus abdominis and external oblique had significantly higher average integrated amplitudes for the b-slide exercise during eccentric movement. Factors affecting abdominal muscular endurance Other muscles involved during abdominal endurance test While an abdominal muscular endurance test was performed, muscles other than abdominal wall might help as synergetic functioning. Carlos et al. (1991) stated that the rectus femoris participated to a great degree when sit-up was performing. In their study, they suggested that the sit-ups performed with extended knees and supported feet required more activity of the rectus femoris than the sit-ups performed with extended knees and unsupported feet. On the other hand, Chong, Lee, Will, shley and Nicole (2006) added that lower

24 23 paraspinal, latissimus dorsi and upper trapezius showed action potential while a full sit-up was performing. Localized muscle fatigue Bryan, Stephen and Lee (2006) defined skeletal muscle fatigue as a reduction in force- and/or velocity-generating capacity of a muscle that has been under load and is relieved with rest. Bryan et al. (2006) added that abdominal muscle fatigue was caused by a reduction in calcium ion release from the sarcoplasmic reticulum and/or damage to the structure of the muscle fiber and the excitation-contraction coupling mechanism. s abdominal muscles were fatigue quickly, the performance of muscular endurance test would be affected. Maestu et al. (2006) stated that the metabolic state of the active muscles played an important role in regulating the recruitment of high threshold motor units, because a close link existed between the state of energy supply and types of muscle fibers being recruited. They pointed out that anaerobic threshold could therefore be considered to be an important

25 24 assessment of the ability of the cardiovascular system to supply oxygen at a rate adequate to prevent muscle anaerobiosis during the exercise, and failure of this mechanism to produce enough oxygen for muscles results in the recruitment of type II muscle fibers that are less oxygen dependent, but less effective, leading to quick fatigue. Different abdominal muscular endurance tests s many abdominal exercises were available, many different types of abdominal muscular endurance tests were developed. Macfarlane (1993) stated that the timed sit up test was commonly used in fitness testing batteries, including the HPERD Physical Best. Liemohn (1991) criticized that modified 1-minute timed sit-up test which was specifically adopted as a test that isolated the abdominal muscles and was assumed to be a safer test than the straight-legged sit-up. On the other hand, Gloria et al. (1997) pointed out that sit-up exercise should be avoided for patients with acute or subacute low back pain. They added that due to concern about

26 25 the safety of executing a sit-up, the abdominal crunch came into favor. Other than abdominal crunch, curl-up test was an alternative of abdominal muscular endurance test. Philip, Mindy and Teresa (1997) developed a cadence curl-up test for college students, which was valid to measure the abdominal muscular endurance. fter experiments, they found that the cadence curl-up test activated the abdominal muscles with less reliance on hip flexor musculature when compared with HPERD sit-up test (1-minute sit-up test). Tony, Harold, Robert and Brett (2001) suggested that the half sit-up was reliable and should be considered as an alternative to the full sit-up for fitness testing in middle school physical education programs as well. They stated that using full sit-up as a measurement of abdominal strength and endurance because studies had shown that the abdominals were not isolated and measurements were confounded by other muscle activity. In other words, the hip flexors became involved with a full sit-up, especially if the feet were held down.

27 26 Motivation Motivation to perform abdominal muscular endurance test was also an important factor, which would affect the test result to certain degree. Leger and Gadoury (1989) pointed out that lack of motivation might result in test ceasing, before participants have reached their physiological limits. On the other hand, they added that maximum effort tests require well-motivated subjects. Setting of the test Setting of the test would affect the performance of the test as well. In timed sit-up test, time limited was a factor that might affect the test result. Docherty (1996) defined that muscular endurance as the ability of a muscle, or muscle group, to generate force repeatedly or for an extended period of time. Hence, limited time shall not be existed in a muscular endurance test. Once limited time was given in timed sit-ups test, speed of repetition of sit-ups would become an important factor with respect to his abdominal muscular endurance.

28 27 Carlos et al. (1991) found that control of the speed of execution of exercises was one of the factors that affected the result of abdominal test. YMC (1989) also pointed out that slow curl-up test was more preferable because timed sit-up test was emphasized the speed all tend to involve muscle groups other than the abdominals. Summary of literature review Strong abdominal muscles was an important consideration for activities of daily living, sports performance, and the rehabilitation of low back pain (David et al., 2005). The 1 minute sit-up test had been widely used as a test of abdominal muscular strength and endurance (HPERD, 1980). There were many factors affecting the individual s performance of the test, such as other muscles involved during the test, localized muscle fatigue, motivation or setting of the test. YMC (1989) pointed out that timed sit-up was emphasized speed all tend to involved muscle groups other than the abdominals. This study was designed to examine the validity of 1 minute

29 28 sit-up test by assessing the correlation between the 1 minute sit-up result with that having fixed frequency and no time limit. Definition of Terms The following terms were defined operationally: Health-related physical fitness ccording to merican College of Sport Medicine (2003), health-related physical fitness actually has four components: aerobic fitness, muscular fitness, flexibility and body composition. Muscular fitness is the strength and endurance of individual s muscles. Muscular Strength Docherty (1996) stated that the International System of Units (SI) defined strength as the maximal force or torque developed by a muscle, or muscle group, during one maximal voluntary action of unlimited duration at a specified velocity of movement. Muscular Endurance

30 29 Docherty (1996) defined that muscular endurance is the ability of a muscle, or muscle group, to generate force repeatedly or for an extended period of time. bdominal Wall The muscles of anterior abdominal wall consist of rectus abdominis, external abdominal oblique, internal abdominal oblique and transverses abdominis. These muscles responsible to flex and rotate vertebral column, compress abdomen and depress thorax (Rod, Trent & Philip, 2006). Sit-up William ed al. (1999) defined the term of sit-up as the specific movement from a supine position of hip flexion without lumbar flexion. It is the body movement which involves abdominal muscular contraction. Timed Sit-up Test Timed sit-up test is widely described as a test of abdominal muscular strength and endurance (Gail, Ronald, David & rthur, 1992). It is a test which individual is asked to perform as

31 30 many sit-ups as possible in one minute. ccording to Teacher s Handbook of Physical Education School Physical Fitness ward Scheme (2007), the objective of the timed sit-up test was supposed to measure the abdominal muscular strength and endurance. Fatigue ccording to Rod et al. (2006), fatigue is defined as the decreased capacity to do work and the reduced efficiency of performance that normally follows a period of activity. ction Potential ction potential is defined as the change in membrane potential in an excitable tissue that acts as an electric signal and is propagated in an all-or-none fashion (Rod et al., 2006). Motivation Motivation refers to what energizes human behavior, or what directs or channels such behavior and to how this behavior is maintained or sustained over an extended period of time

32 31 (Tisgilis, 2005). Intrinsic Motivation Tisgilis (2005) stated that intrinsic motivation refers to performing an activity purely for the enjoyment and satisfaction derived from participation. n intrinsically motivated individual performs the behavior voluntarily, in the absence of material rewards or external constraints. Research Hypothesis ccording to the above literatures reviewed, it was hypothesized that: 1. There would be no significant correlation between the performance of the timed sit-ups and that of sit-ups with no time limit in participants.

33 32 Chapter 3 METHOD The purpose of this study was to examine the validity of 1-min sit-up test by assessing the correlation between the 1-min sit-up result with that having fixed frequency and no time limit. This chapter was divided into the following parts: (a) subjects; (b) procedures; (c) method of analysis; and (d) statistical hypothesis. Subjects One hundred and fifteen secondary schools students, who studied in Tai Po Government Secondary School and aged between 14 and 17 years old, were invited to participate in the timed sit-up test (test 1) and the sit-up test with no time limit (test 2). Before the study, subjects and their guardians were asked to sign on the consent forms after knowing the purpose, benefits and risks of the study. Procedures In this study, subjects were invited to perform test 1 and

34 33 test 2 in randomly sequences on two separate days within a week. Both tests were conducted in the covered playground of the Tai Po Government Secondary School. Timed sit-up test (test 1) The subjects were strongly advised not to have a heavy meal 2 hours before the sit-up tests. The subjects were invited to do warm up exercises. Warm up exercises included 5 minutes jogging around the covered playground and then 5 minutes related stretching exercises. fter the warm up exercises, subjects were invited to perform the test 1. The description of the test 1 was described by the Teacher s Handbook of Physical Education School Physical Fitness ward Scheme (2007): The student lies on the mat with knees bent and the feet are held flat down firmly by a partner. The heels should be 30 to 45 cm from the buttocks, such that the angle between the thigh and the floor is about 45 degrees. rms are crossed in front of the chest with hands on the opposite shoulders.

35 34 The chin is tucked to the chest. The student lies in supine position. In response to the starting signal, he/she curls up until the elbows touch the thighs, and then uncurls until the mid-back contacts the mat. This is counted as one time. The teacher should encourage the student to repeat as many sit-ups as possible within one minute. The student may rest in a lying or sitting position during the test. HPERD (1976) added that no resting was permitted between sit-ups, and only correct sit-ups could be counted. Figure 1 showed the setting of the sit-up test: Figure 1. The setting of the timed sit-up test.

36 35 In this study, the above procedures were followed. However, the partner was changed to a test assistant, who was found in the secondary school and learnt how to be the test assistant prior to the test. fter subjects performed the test, localized stretching exercises were advised to do. Sit-up test with no time limit (test 2) Test 2 was similar to the test 1. ll the testing procedures were remained the same as the test 1, except one minute limitation. Subjects were asked to perform as many sit-ups as they could continuously until volitional exhaustion. Subjects were said to be volitional exhaustion when they were not able to perform an entire sit-up motion. Similarly, as HPERD (1976) added, no resting was permitted between sit-ups, and only correct sit-ups could be counted. If obvious resting was detected, the test was said to be finished. Delimitations The following delimitations were included in this study: 1. The subjects of the study were delimited to the male and

37 36 female students who studied in Tai Po Government Secondary School and aged between 14 to 17 years old. 2. Total of 115 subjects were involved in this study. 3. The Timed Sit-up Test was carried at the covered playground of the Tai Po Government Secondary School. 4. The Sit-up Test with no time limit was carried at the covered playground of the Tai Po Government Secondary School. 5. The Timed Sit-up Test and the Sit-up Test with no time limit were tested on two separate days within a week. Data nalysis Statistical hypothesis The following null hypothesis was examined: 1. There would be a significant correlation between the performance of the timed sit-ups and that of sit-ups with no time limit in participants. Statistical nalysis Data were reported as mean and standard deviation. Minimum

38 37 and maximum values of variables were analyzed by the Statistical Package for Social Science (SPSS). Pearson Production Moment Coefficient of Correlation (r) was used to examine the correlation between the 1-min sit-up result with that having fixed frequency and no time limit. n alpha level of p<0.05 indicated statistical significance. Limitations The following limitations were included in this study: 1. The motivation of the subjects in performing the sit up tests, especially sit up test with no time limit, were uncontrollable. It might affect the results of the study. 2. The performance of the subjects might affected because of their physical lifestyle and the physical activity level. 3. The performance of the subjects might affected due to their different physical characteristics. 4. Study findings are applicable only to the subjects included in this study.

39 38 Chapter 4 RESULTS Seventy male and forty-five female students of Tai Po Government Secondary School were invited to participate in this study. The purpose of this study was to examine the validity of 1 minute sit-up test by assessing the correlation between the 1 minute sit-up result with that having no time limit. ll subjects engaged in 1 minute sit-up test and sit-up test with no time limit. The physical characteristics of the subjects were shown in the table 1: Table 1 Physical characteristics of the subjects (N=115) Range Mean ±SD ge (yr) Height(cm) Weight(kg)

40 39 The descriptive statistics of the subjects performance in the Timed Sit-up Test (Test 1) and the Sit-up Test with no time limit (Test 2) were shown in table 2: Table 2 Descriptive statistics of the subjects performance in the test 1 and test 2 (N=115) Range Mean ±SD Test 1 (rep) Test 2 (rep) Test 1: Timed Sit-up Test Test 2: Sit-up Test with no time limit The Pearson correlation between the subjects performance in the Timed Sit-up Test (Test 1) and the Sit-up Test with no time limit (Test 2) was computed. The Pearson correlation coefficient and the coefficient of determination were shown as the following Table:

41 40 Table 3 Pearson s correlation test between the subjects performance in the Timed Sit-up Test (Test 1) and the Sit-up Test with no time limit (Test 2) (N=115) r r 2 p Correlation between.709** Test 1 and Test 2 ** Correlation is significant at the 0.05 level (2-tailed) The relationship between the subjects performance of the Timed Sit-up Test (Test 1) and that of the Sit-up Test with no time limit (Test 2) showed the positive relationship roughly. Using the Pearson product-moment correlation coefficient, the finding showed that the correlation between the two tests was significant. The following figure showed the relationship between the subjects performance of Test 1 and that of Test 2:

42 41 Figure 2 Scatter plotted graph showing the relationship between the subjects performance of the Timed Sit-up Test (Test 1) and that of the Sit-up Test with no time limit (Test 2) Sit-up Test with no time limit min Timed Sit-up Test s aforesaid, the correlation between the subjects performance of Test 1 and Test 2 was significant. Hence, the null hypothesis there will be significant correlation between the performance of the timed sit-ups and that of

43 42 sit-ups with no time limit in participants was accepted. Discussion The purpose of this study was to examine the validity of 1-minute sit-up test by assessing the correlation between the 1-minute sit-up result with that having no time limit. In the following discussion part, three parts would be divided: (1) Relationship between the performance of Timed Sit-up Test and that of Sit-up Test with no time limit, (2) factors affected the performance of both sit-up test, and (3) review of the settings of both tests. Relationship between the performance of Timed Sit-up Test and that of Sit-up Test with no time limit Timed Sit-up Test had always been included in many physical fitness tests batteries. The merican lliance for Health, Physical Education, Recreation and Dance (HPERD) put timed sit-ups into a four items test battery that evaluated physical fitness related to lifelong health (HPERD, 1976). In addition, schools and security forces used timed sit-up test

44 43 to assess candidates abdominal muscular endurance as well. However, there were few longitudinal researches to investigate the factor of time in the sit-up test. ccording to the present study, it was found that there was significant correlation between the performance of timed sit-up test and that of sit-up test with no time limit (r = 0.709, p < 0.05). However, only 50.3% (r 2 = 0.503) of the variance was shared. In other words, the coefficient of nondetermination was 49.7%, which was attributed to factors other than abdominal muscle endurance, such as the difference between the settings of both tests and subjects motivation to perform the tests. Factors affected the performance of both sit-up tests Since both tests involved in this study were sit-up tests, the factor of different abdominal muscular endurance tests was eliminated. s subjects were asked to perform the same motion in the both tests, the factor of other muscles involved during abdominal endurance test was also cancelled mutually.

45 44 The main difference of the both tests was the setting. For timed sit-up test, one minute was limited; for the alternative test, no time was limited. The setting would affect subjects performance directly, especially from the view of motivation. Subjects would have be more motivated to perform sit-ups in the timed sit-up test, as they would not fall into the exhaustion phase. For the sit-up test with no time limit, when subjects did their best in the test, localized muscle fatigue would probably be created and they would feel painful. Because of those negative reinforcements, their motivation of performing sit-up test would be reduced. Leger and Gadoury (1989) pointed out that lack of motivation might result in test ceasing, before participants have reached their physiological limits. Review of the settings of both sit-up tests The only difference of the both sit-up tests was the time limitation. For timed sit-up test, one minute was given to candidates to perform as many repetitions of sit-up as they

46 45 can. For sit-up test with no time limit, candidates were only asked to perform as many repetitions of sit-up as they can, no time limitation was given. lthough the present study found that both test results were correlated, The coefficient of determination was only In other words, the variance shared by or common to the variables is only 50.3%. In contrary, the coefficient of nondetermination was 49.7%. It meant that there were still nearly 50% of the variance was not shared and was attributed to other factors. s a result, it was proved that time factor might induce other factors that would affect the validity of the sit-up test. Docherty (1996) defined that muscular endurance is the ability of a muscle, or muscle group, to generate force repeatedly or for an extended period of time. Based on the definition, sit-up with no time limit was a standard to measure abdominal muscular endurance because extended period of time was given. Since statistic in the present study proved that

47 46 both tests were correlated, it was proved that the timed sit-up test also had high validity to measure abdominal muscle endurance. Based on the above conclusion, for the consideration of time control, time limitation seems to be a better system in realistic life. For school curriculum, the physical test will be always carried out in P.E. lessons. It is rushed to test all students in an uncontrolled time. On the other hand, for the other physical tests such as security forces physical tests, large amount of candidates will be invited to perform physical tests. From the view of administration and management, it is better to give time limitation when the validity of the timed sit-up test was proved by previous researches.

48 47 Chapter 5 SUMMRY ND CONCLUSIONS Summary of Results The present study was designed to examine the validity of 1-minute sit-up test by assessing the correlation between the 1-minute sit-up result with that having no time limit. Seventy male and forty-five female students of Tai Po Government Secondary School were participated in this study. They performed timed sit-up test and sit-up test with no time limit respectively in the covered playground of the Tai Po Government Secondary School. The repetitions of both sit-up tests were recorded, and the test results data were analyzed by Statistical Package of Social Science (SPSS). Pearson Product Moment Coefficient of Correlation (r) was used, and 0.05 level of significance was set. The results of this study were summarized as follows: 1. There was significant positive relationship between subjects performance of the timed sit-up test and that

49 48 of the sit-up test with no time limit (r = 0.709, p < 0.05, N = 115). 2. The common variance of the two tests was 50.3% (coefficient of determination = 0.503). 49.3% of the variance was not shared and was attributed to factors other than abdominal muscle endurance. Conclusion From the findings, it was found that there was significant positive relationship between subjects performance of the timed sit-up test and that of the sit-up test with no time limit. Since statistic in the present study proved that both tests were correlated, it was concluded that the timed sit-up test was valid for examining one s abdominal muscle endurance. Recommendation of Further Study 1. The age group, the sex group should be extended, since there might have differences in abdominal muscle endurance. 2. Body fat percentage of the subjects should be considered as well, since there might have difficulty in performing

50 sit-up when individual s body fat percentage is high. 49

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55 54 PPENDIX Data Collection Form Name: Subject No.: ge: Gender: Height: cm Weight: kg 1 st Test: (Date) T / N 2 nd Test: (Date) T / N T = Timed Sit-up Test N = Sit-up Test with no time limit Data Collection Form Name: Subject No.: ge: Gender: Height: cm Weight: kg 1 st Test: (Date) T / N 2 nd Test: (Date) T / N T = Timed Sit-up Test N = Sit-up Test with no time limit

56 PPENDIX B 仰臥起坐測試內容及家長同意書 本人是香港浸會大學體育及康樂管理學系三年級學生, 現正進行一項有關仰臥起坐測試的研究 本人希望邀請貴子弟參加是次仰臥起坐測試, 唯貴子弟必須得到閣下批准, 方可進行測試 請閣下詳閱下列細則 : 1. 測試目的及內容貴子弟將會進行兩項測試, 分別為一分鐘仰臥起坐測試及無時限仰臥起坐測試 參加者會被安排仰臥在墊子上, 並由測試助理協助固定腳部 在一分鐘仰臥起坐測試進行時, 參加者需在一分鐘內, 完成最多仰臥起坐次數 ; 在無限時仰臥起坐測試進行時, 參加者需盡力不間斷地完成最多仰臥起坐次數 是次測試目的, 是希望透過實驗, 找出時間限制在仰臥起坐測試中的重要性 2. 存在風險及不適感覺是次測試需要貴子弟盡力做到最多仰臥起坐次數 因涉及肌力及肌耐力, 參加者在完成測試後, 可能會感到腹肌部位有少許痛楚 所有不合理的動作將會立即被停止, 把受傷風險盡量降到最底 急救用品及有急救牌照的工作人員亦會從旁協助, 如有任何意外亦可即時處理 3. 參加者的責任如參加者本身有任何肌肉受傷或其他不尋常的不適感覺, 參加者有責任於測試前向測試工作人員報告有關資料 如有任何其他藥物背景, 參加者亦需於測試前向工作人員報告 4. 參加測試將會得到的好處參加是次測試, 可以幫助參加者認識自己的腹肌耐力 5. 詢問如有任何關於測試項目內容的疑問, 隨時歡迎提出 6. 測試結果的運用參加者所有個人資料及測試結果, 只用於是次研究作統計及科學分析用途 為了保護參加者個人私隱, 如沒有參加者的書面同意, 所有資料一概不會向任何人公開 7. 參加者的意願參加者參加是次測試, 是出於自願性質的 如果參加者在測試前或測試期間感到不適, 或不願意進行測試, 可在任何時候選擇退出測試, 並不會有任何後果

57 56 參加者責任聲明及家長同意聲明 : 本人 身體健康狀況良好, 適宜參加上述的仰臥起坐測試 本人並未有任何疾病, 適合參與是次測試, 包括一分鐘仰臥起坐測試及無限時仰臥起坐測試 如有疑問, 本人會向醫生尋求指示 在測試期間, 如發生意外而導致任何事故, 本人願承擔全部責任, 主辦或協機構並不需要負上任何法律責任 此外, 本人亦明白必須遵守是次測試的工作人員之安排 確認日期 : 參加者簽名 : * 未滿 18 歲的參加者, 必須填妥以下部份 : 家長 / 監護人姓名 : 家長 / 監護人簽名 : 與參加者之關係 : 日期 :