The goal of this randomized crossover study is to investigate the effects of plyometric training, functional training, and whole-body electrical muscle stimulation (WB-EMS) on athletic performance and health in university basketball and volleyball players. The main questions it aims to answer are: 1. Which training modality (plyometric, functional, or WB-EMS) leads to the greatest improvements in athletic performance measures such as power, speed, and agility? 2. How do these training modalities compare in terms of their effects on overall health, injury risk reduction, and psychological well-being? Researchers will use a crossover design, where each participant experiences multiple training modalities in a sequential manner, to provide a more rigorous and comprehensive evaluation of the interventions' effectiveness. Participants will: 1. Be randomly assigned to one of four training sequences, each consisting of two 8-week intervention periods separated by a 4-week washout phase; 2. Experience at least two of the three training modalities (plyometric, functional, or WB-EMS) during the intervention periods; 3. Maintain their regular training routines if assigned to the control group; 4. Undergo assessments, including anthropometric measurements, physical fitness tests, and questionnaires, at baseline, after each intervention period, and during a follow-up session. The findings of this study will provide valuable insights into the optimal sequencing and combination of training modalities to maximize athletic performance and promote health among university basketball and volleyball players.
Background: Enhancing athletic performance and reducing injury risk require effective training techniques. University athletes, often practicing only 2-3 times a week, need support to reach optimal fitness. This study examines the effects of plyometric, functional, and WB-EMS training on the health and performance of collegiate basketball and volleyball players. Objective: The primary aim is to evaluate the effectiveness of these training modalities in improving athletic performance metrics such as strength, speed, agility, and endurance. Secondary aims include determining their influence on recovery and injury prevention and exploring potential differences in response among athletes from different sports disciplines. Study Design: This is a randomized crossover study. Participants will be randomly allocated to one of four groups: plyometric training, WB-EMS training, functional training, or control group. The intervention will consist of two 8-week training periods separated by a 4-week washout period. Participants: 120 male and female basketball and volleyball players aged 18-30 from University teams in Macau will be recruited. They should have at least 3-4 years of competitive experience in their respective sports. Interventions: The plyometric group will focus on explosive movements and jumps. The WB-EMS group will perform exercises while receiving electrical stimulation. The functional training group will engage in sport-specific exercises. The control group will maintain their regular training. Each session will include a warm-up, specific exercises, and a cool-down. Outcome Measures: Participants will undergo assessments at baseline, post-intervention, and follow-up. These include anthropometric measurements, physical fitness tests (e.g., Y-Balance Test, FMS, 1RM half-squat, leg muscle volume, vertical jump, agility, sprint), and questionnaires (e.g., ERQ, PSQI, SES, SWLS). Statistical Analysis: Mixed-design ANOVA or ANCOVA will compare the effects across time points. Post-hoc tests will determine specific differences between groups and time points. Significance will be set at p value smaller than 0.05.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
NONE
Enrollment
120
Whole-Body Electrical Muscle Stimulation (WB-EMS) Training is a novel training modality that involves the simultaneous electrical stimulation of multiple muscle groups while performing dynamic exercises. Participants in the WB-EMS Training Group will use the miha bodytec device (Augsburg, Germany), which consists of a special suit with integrated electrodes covering major muscle groups. The device generates electrical impulses (85 Hz, 350 μs) that cause involuntary muscle contractions during exercises like squats, lunges, and trunk rotations.Each 20-25-minute WB-EMS session will be conducted twice a week during the two 8-week intervention periods. Sessions will include a warm-up followed by 4-6 WB-EMS exercises performed for 4-6 seconds each, with 4 seconds of rest between exercises. The intensity of the stimulation and exercises will be progressively increased based on individual adaptation and tolerance, with the stimulation intensity set at 70-85% of the maximal tolerable level.
Plyometric Training is a high-intensity, explosive strength training modality that involves quick, powerful movements designed to increase muscle power, speed, and agility. Participants in the Plyometric Training Group will engage in a progressive plyometric training program that emphasizes eccentric muscle loading followed by rapid concentric contractions. The plyometric exercises will include various types of jumps, hops, and bounds, such as box jumps, depth jumps, split squat jumps, and single-leg hops. Each training session will begin with a dynamic warm-up, followed by 4-6 plyometric drills performed for 3-5 sets of 8-12 repetitions, with 60-90 seconds of rest between sets. The intensity and volume of the exercises will be gradually increased over the two 8-week intervention periods.
Functional Training is a training approach that focuses on exercises that simulate the demands of specific sports or daily activities, targeting multiple muscle groups and movement patterns simultaneously. Participants in the Functional Training Group will engage in a tailored functional training program designed to enhance their performance in basketball or volleyball. The functional training exercises will incorporate multi-joint, multi-planar movements that mimic game-specific actions, such as multidirectional lunges, rotational medicine ball throws, and single-leg balance drills. Each session will start with a dynamic warm-up, followed by 6-8 functional exercises performed for 3-4 sets of 8-12 repetitions, with 60 seconds of rest between sets. The program will also include core stability and injury prevention exercises.
UM Sports Complex (N8) , Avenida da Universidade Taipa, Macau, China
Macao, Macau
RECRUITINGUniversity of Macau
Taipa, Macau
NOT_YET_RECRUITINGSquat Jump (SJ) Test
The squat jump is a performance test used to measure the explosive power of an athlete's lower extremities, particularly focusing on the ability to generate force from a static position. Participants begin by standing with their feet shoulder-width apart, then descend into a squat position until their thighs are parallel to the ground. From this static squat position, they explosively jump as high as possible without the assistance of arm movement. This test typically involves performing two jumps, with a 45-second rest interval between jumps. The highest jump (cm) from the two attempts is recorded. A three-dimensional force platform, the Just Jump system NO101 (Probotics Inc.), is commonly used to measure and collect height data during the jumping process. The test is significantly correlated with explosive power and athletic performance, demonstrating excellent reliability with an intra-session ICC of 0.97 and an inter-session ICC of 0.94.
Time frame: From enrollment to the end of intervention at 20 weeks（8 weeks for phase 1,4 weeks for wash out and 8 weeks for phase 2）
Countermovement Jump（CMJ）
Participants are required to stand with their feet shoulder-width apart, toes slightly pointing outwards, and hands placed on their hips to prevent arm movement, allowing for an accurate assessment of lower extremity explosive power. At the start of the test, participants rapidly bend their knees, lowering their center of gravity until their knees reach approximately a 90-degree angle, then quickly extend their knee, hip, and ankle joints, jumping upwards with maximum effort. Each movement is performed twice, with a 45-second rest interval between jumps. The best jump height data (cm) is recorded. Jump height data during the jumping process is collected using a three-dimensional force platform NO101 (Just Jump, Probotics Inc.). The CMJ is a widely used and validated method for assessing jumping ability and explosive power, demonstrating good reliability and validity with an intra-session ICC of 0.95 and an inter-session ICC of 0.93.
Time frame: From enrollment to the end of intervention at 20 weeks（8 weeks for phase 1,4 weeks for wash out and 8 weeks for phase 2）
Running Jump Off Test
The running jump off test requires participants to first stand directly beneath the apparatus, with their feet flat on the ground and one arm extended upwards to measure their standing reach height. The subject then stands approximately 15 feet (about 5 meters) from the base of the apparatus. In preparation for the jump, they take 3 to 5 steps, then take off from both legs (or a single leg, depending on the specific requirements of the test), using their arms to help propel their body upwards. The goal is to have the body positioned directly beneath the apparatus at the peak of the jump, with arms fully extended, which may require some practice to perfect the timing and takeoff point. The difference between the standing reach height and the highest point touched during the jump is recorded, with the best result (cm) from three attempts being noted. The vertical jump apparatus is used, demonstrating good reliability with an ICC ranging from 0.90 to 0.96.
Time frame: From enrollment to the end of intervention at 20 weeks（8 weeks for phase 1,4 weeks for wash out and 8 weeks for phase 2）
Modified 505 Change of Direction Test
The 505 Change of Direction (COD) test, performed from a stationary start, evaluates an athlete's ability to execute a rapid 180° turn within a 5-meter distance. The athlete begins the test from a standing position, placing their preferred foot half a meter behind the starting line and using this foot as the turning pivot. Each athlete performs three attempts, with the fastest completion time (s) recorded using precise timing equipment. A two-minute rest period is provided between each trial. According to the definition by Nimphius et al., the change of direction deficit (CODDEF) for the 505 test is determined using the following formula: CODDEF = (Modified 505 test time - 10-meter sprint time). This test demonstrates good reliability with an ICC of 0.87 and is highly correlated with the standard 505 test, with a correlation coefficient (r) of 0.87.
Time frame: From enrollment to the end of intervention at 20 weeks（8 weeks for phase 1,4 weeks for wash out and 8 weeks for phase 2）
Sprint 4 × 5 m Test
The setup requires 5 cones placed 5m apart. The subject stands with feet apart, straddling a cone between their legs. Upon hearing an auditory signal, they run 5 meters to point A; then turn 90° to the right and run 5 meters to point B. After the second 90° turn, they run to point C, where they make a 180° turn and run to the finish line. Each athlete performs three attempts, with the fastest completion time (s) recorded using precise timing equipment. A two-minute rest period is provided between each trial. This test demonstrates good reliability with an ICC ranging from 0.88 to 0.91.
Time frame: From enrollment to the end of intervention at 20 weeks（8 weeks for phase 1,4 weeks for wash out and 8 weeks for phase 2）
Modified Agility T-Test (MAT)
The Modified Agility T-Test (MAT), developed by Radhouane et al., is based on the traditional T-test and aims to assess an athlete's ability to quickly change direction, including forward sprinting, lateral shuffling, and backward movement. MAT adjusts the spatial layout of the original T-test, reducing the total running distance from 36.56 meters to 20 meters while maintaining the same types of movements and number of direction changes, adapting to space-constrained environments. Each athlete performs three attempts, with the fastest completion time (s) recorded using precise timing equipment. A two-minute rest period is provided between each trial. The test has high reliability with an ICC ranging from 0.82 to 0.96 and is highly correlated with the standard T-test, with a correlation coefficient (r) of 0.92, effectively differentiating athletes' agility performance.
Time frame: From enrollment to the end of intervention at 20 weeks（8 weeks for phase 1,4 weeks for wash out and 8 weeks for phase 2）
Functional Movement Screening (FMS)
The FMS Functional Movement Screening Test Tool (FMS, Perform Better, USA) is a system that assesses an individual's motor control stability, body balance, flexibility, and proprioception when completing basic movement patterns. As shown in Table 3, the following is a brief operation process and scoring standard for the seven basic movements of the FMS test. Each item is scored from 0 to 3 points, with a total score of 0 to 21 points. 0 points: Pain occurs during the test; 1 point: Unable to complete. The movement may not be able to maintain the starting posture; 2 points: Able to complete the movement, but the quality of the movement is not high; 3 points: The movement is completed with high quality. Functional movement screening is completed using the FMS test kit. The FMS is a widely used and validated method for measuring human dynamic balance and assessing injuries, demonstrating good reliability and validity with an ICC ranging from 0.87 to 0.98.
Time frame: From enrollment to the end of intervention at 20 weeks（8 weeks for phase 1,4 weeks for wash out and 8 weeks for phase 2）
Y balance test (YBT)
The subjects stood barefoot on one leg using a test instrument (Y-balance, Performance Health, USA). The non-supporting leg was stably extended to the farthest distance in three directions: forward, backward inward, and backward outward, and held for 3 seconds. Practice 3 times on each side before the test, rest for 5 minutes before officially starting the test, and test 3 times in each direction. The test index is the relative value of the legs on each side. Relative value of each leg (%) = (anterior + posteromedial + posterolateral) / (3\*leg length in lateral lying position). The higher the relative value of each leg means better lower limb dynamic balance ability, and more Optimum lower limb mobility and flexibility, and potentially lower risk of lower limb injury.The Y balance test is a widely used and validated method for measuring human dynamic balance and assessing injuries, demonstrating good reliability and validity with an ICC ranging from 0.91 to 0.99.
Time frame: From enrollment to the end of intervention at 20 weeks（8 weeks for phase 1,4 weeks for wash out and 8 weeks for phase 2）
Pittsburgh Sleep Quality Index (PSQI)
The Pittsburgh Sleep Quality Index (PSQI) is a widely used self-report measure of sleep quality, containing 18 self-rated items across seven components: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction. Each item is scored on a scale of 0-3, with a total score range of 0-21 for the seven components. Higher scores indicate poorer sleep quality. The scale has demonstrated good internal consistency reliability, with a Cronbach's α ranging from 0.80 to 0.83, and a test-retest reliability ranging from 0.85 to 0.87. Liu Xianchen et al. conducted a Chinese revision and validation of the PSQI, confirming that the Chinese version is an effective tool for assessing sleep quality.
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Time frame: From enrollment to the end of intervention at 20 weeks（8 weeks for phase 1,4 weeks for wash out and 8 weeks for phase 2）
Self-Efficacy Scale (SES)
The Self-Efficacy Scale (SES) is a 13-item self-report scale designed to assess an individual's beliefs about their own capabilities. Each item is scored on a scale ranging from 1 (strongly disagree) to 7 (strongly agree), with a total score range of 13-91 for the 13 items. Higher scores indicate stronger self-efficacy. The scale has an internal consistency reliability (Cronbach's α) of 0.91. The SES was originally developed by Schwarzer and Jerusalem and has been widely applied across different cultural contexts.
Time frame: From enrollment to the end of intervention at 20 weeks（8 weeks for phase 1,4 weeks for wash out and 8 weeks for phase 2）
Satisfaction With Life Scale (SWLS)
The Satisfaction With Life Scale (SWLS) is a brief 5-item self-report scale used to assess an individual's overall satisfaction with their life. Each item is scored on a scale ranging from 1 (strongly disagree) to 7 (strongly agree), with a total score range of 5-35 for the 5 items. Higher scores indicate greater life satisfaction. The SWLS has an internal consistency reliability (Cronbach's α) of 0.87 and is positively correlated with multiple indicators of well-being, supporting its validity. Wu Minglong conducted a Chinese revision and cross-cultural validation of the SWLS, and the results demonstrated that the Chinese version of the SWLS also has good reliability and validity.
Time frame: From enrollment to the end of intervention at 20 weeks（8 weeks for phase 1,4 weeks for wash out and 8weeks for phase 2）
Emotion Regulation Questionnaire (ERQ)
The Emotion Regulation Questionnaire (ERQ) is a 10-item self-report scale used to assess an individual's habitual use of two emotion regulation strategies: expressive suppression and cognitive reappraisal. Each item is scored on a scale ranging from 1 (strongly disagree) to 7 (strongly agree), with a total score range of 10-70 for the 10 items. Higher scores indicate a greater tendency to use the corresponding emotion regulation strategy. The scale contains two subscales: expressive suppression (4 items) and cognitive reappraisal (6 items). The internal consistency reliability for these subscales is strong, with Cronbach's α values ranging from 0.73 to 0.79 for expressive suppression and from 0.75 to 0.82 for cognitive reappraisal. Wang Dandan et al. conducted a Chinese revision of the ERQ, also demonstrated good psychometric properties. In this study, the questionnaire is primarily distributed to subjects in paper form, to be completed within one hour after testing and training.
Time frame: From enrollment to the end of intervention at 20 weeks（8 weeks for phase 1,4 weeks for wash out and 8 weeks for phase 2）