The aims of a pre-exercise warm up are to optimize the performance of competitive and non-competitive participants by increase total body and physiological response (Bishop, 2003). The nature of basketball world was complex and consisted of a lot of ability, techniques and skills. The fitness components for a basketball player must include power and anaerobic ability. Vertical jump was one of the important and essential elements of basketball players. Vertical jump was performed by knee extension, hip extension and ankle plantar flexion and carried out with several lower limb muscles such as quadriceps, hamstrings and gastronemius (Maarten F. Bobbert, Karin G. M. Gerritsen, Maria C. A. Litjens, and Arthur J. Van Soest, 1996)Basketball, a competitive sport that consisted different physical ability, simple or difficult techniques, single and complex skills. Cardiovascular Endurance, speed and anaerobic capacity were essential elements for a basketball player   Statement of ProblemThe effect of static stretching and dynamic stretching on sprinting, jumping and agility of basketball player are discussed among the majority of published literatures. However, the stretching effect on high-intensity aerobic work was not well studied. In fact, static stretching is generally recommended for pre-exercise warm-up. On the other hand, there are some literatures demonstrating that static stretching would impair repeated-sprint performance due to increase of muscle and tendon compliance. Meanwhile, there are some literatures suggested that dynamic stretching would not affect the repeated-sprint performance but only affect the fastest sprint time during the test.Hypothesis1.        There would be significant difference between the performance of the Yo-Yo intermittent recovery test (level 1) among static stretching, dynamic stretching and without stretching. Significance of the StudyThe purpose of the study is to investigate the effects of different stretching exercises on Yo-Yo intermittent recovery test (level 1). Yo-Yo intermittent recovery test is the most relevant single field performance to estimate basketball players’ cardiorespiratory fitness level, while cardiorespiratory fitness level of the basketball player is vital to their performance of the game. Therefore, the result of this research could suggest the appropriate choice for players with corresponding stretching method for players to warm up.Chapter 2 REVIEW OF LITETATURESummaryChapter 3 METHODSample of SelectionTwelve male basketball players from HKFYG Lee Shau Kee College were invited in terms of volunteer basis, who aged between 14-17. All of the participants were physically available to take part in this test by completing the Physical Activity Readiness Questionnaire (PAR-Q). Also all participants were understand the who testing procedures and the aim of this study by signed a consent form and involved in a information session one week prior to the testing session. In addition, all of the participants are under 18 years old, thus their parents were signed a consent form and agree their children to participate in this test. There were 6 pretest instruction stated in ACSM’s Guideline for Exercise Testing and Prescription (ACSM, 2006,//ACSM, (2006).ACSM’s Guidelines for Exercise Testing and Prescription, 7th ed. USA: Lippincott Williams & Wilkins) that were informed to all participants before the test.Wear loose-fitting, comfortable clothes that will easily allow participant to exercise during the test.Food, alcohol, and caffeine are not recommended for at least 3 hours before the test.Drink great amount of fluids within 24 hours before the test.Avoid vigorous exercises on the day of the test.Get enough sleep ( > 6-8 hours) on the night that before the date of testAll of the instruction with the test would be provided to the participants before their arrival to the testing venue.Participants were performed all three warm-up method in three separate testing date and separated at least 48 hours in between. So as to minimize order effects, three method were allocated to participants in random on each testing day(see Table 1).In order to minimize the effect of sneakers that might brought to the testing performance, all participants were required to wear the same pair of sneaker in all three testing days. After the performance test, a cool down procedure led by the instructor was followed up. All personal data in data collection form (see appendix C) were completed before the tests and kept confidentially.Table 1.Allocated order of stretching method to each participantSubject Day 1 Day 2 Day 31 NS DS SS2 SS NS DS3 SS DS NS4 DS NS SS5 NS SS DS6 DS SS NS7 DS NS SS8 SS DS NS9 NS SS DS10 SS NS DS11 NS DS SS12 DS SS NS*NS: No Stretching; SS: Static Stretching; DS: Dynamic StretchingTesting ProceduresAll performance tests were processed in the basketball court in HKFYG Lee Shau Kee College. One trained instructor was involved in whole testing period. The trained instructor demonstrated the procedure of static stretching, dynamic stretching and the technique. The trained instructor also described and explained the key points during the familiar session and performance test.Three warm-up methods were different and differentiated based on their stretching content, that included dynamic stretching, static stretching and no stretch. All participants were processed these 3 warm-up methods in 3 separate days in random. With the procedures in stretching, each stretching exercise was followed the exact same steps (see table 2 and 3).Standardized three minutes jogging was applied to all participants, followed up by the assigned stretching method. There were three different stretching method as described in below.No Stretching ( Method A), there would be no stretching exercise after three minutes jogging session.Static Stretching ( Method B), there would be  ….. after three minutes jogging session. ( taDynamic Stretching ( Method C), there would be ….. after three minutes jogging session.The procedures of testingYoYo testDefinition of TermsLimitationsThe attitude of the participants toward to the performance test might affect the result of the test.The motivation of the participants toward to the performance test might affect the result of the test.The living style of participants between each testing session might affect the result of the test.Learning effect might exist and differ from every participants. Participant’s experience was not treated as one of the factors in this study.The weather and humidity of testing date might affect the result of the testDelimitations The participants were delimited to 12 male secondary school basketball players who received regular basketball training.The participants were aged from 14 to 17 years old during the data collection period. All 12 participants were selected from HKFYG Lee Shau Kee College Male Basketball team.The participants were undergo a information session one week before the testing session, which included the procedure of the test and stretching method.All data were collected in February 2018All participants were confirmed themselves in good health status before the testing.All participant’s parents were signed a parent consent form and agree their kids to participant in this testall participants were required to wear the same pair of sneaker in all three testing days for minimizing the effect of sneakers that might brought to the testing performance, .Yo-Yo intermittent recovery test (level 1) were conducted 3 times in total with at least 48 hours apart.All participants were informed not to involved in vigorous exercise 24 hours before the test.Method of AnalysisAll data collected from the test was transferred into the Statistical Package for Social Science(SPSS) for  statistical calculations. The significance level was set at p? 0.05. The descriptive statistics of every variable included standard deviation, mean, subject’s age, subject’s body height and the testing result of Yo-Yo intermittent recovery test (level 1) were calculated in SPSS. One-Way ANOVA test was used to compare the mean differences among of the three different warm-up protocol in the Yo-Yo intermittent recovery test (level 1). When a significant F value achieved, post-hoc comparisons accomplished via a least significant difference (LSD) test to identify specific difference between three different method .