The goal of this clinical trial is to compare two ways of scheduling plyometric training in rope-skipping athletes. The study will examine whether short and frequent training sessions have different effects on lower-limb muscle function, rope-skipping performance, and perceived fatigue compared with longer training sessions performed less often. Approximately 60 rope-skipping athletes will be randomly assigned to one of two groups. Both groups will continue their regular rope-skipping training and complete an additional 8-week plyometric training program. One group will perform short plyometric training sessions five days per week. The other group will perform concentrated plyometric training sessions twice per week. The exercise content, weekly training volume, and training progression will be kept as similar as possible between the two groups. Researchers will assess lower-limb muscle function and rope-skipping-specific performance before and after the intervention. Training attendance, completion, perceived exertion, muscle soreness, and adverse events will also be recorded. The study aims to determine whether distributing plyometric training across more frequent and shorter sessions produces different training effects from concentrating the training into fewer sessions.
This study is an 8-week, two-arm, parallel-group randomized controlled trial designed to compare microdosed plyometric training with traditional concentrated plyometric training in rope-skipping athletes. Approximately 60 eligible participants will be randomly allocated to the microdosed plyometric training group or the traditional concentrated plyometric training group, with approximately 30 participants in each group. Participants in both groups will maintain their regular rope-skipping-specific training throughout the study. The microdosed plyometric training group will perform high-frequency, short-duration plyometric training sessions five days per week. The traditional concentrated plyometric training group will perform plyometric training twice per week using a more concentrated training schedule. The exercise content, total weekly training duration, weekly jump contacts, and progression principles will be kept as consistent as possible between the groups. The main difference will be the frequency and amount of training completed during each session. Lower-limb neuromuscular function and rope-skipping-specific performance will be assessed before and after the 8-week intervention. Assessments will include measures related to lower-limb muscle strength, explosive performance, and sport-specific performance. Researchers will also record training attendance, training completion, perceived exertion, muscle soreness, and adverse events during the intervention. The study will evaluate whether the distribution of plyometric training across the week influences physical performance, sport-specific performance, fatigue responses, and training tolerance in rope-skipping athletes.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
OTHER
Masking
NONE
Enrollment
60
Participants assigned to this intervention will continue their regular rope-skipping-specific training and complete an 8-week microdosed plyometric training program. Plyometric training will be distributed across five sessions per week using a high-frequency, short-duration format. The exercise content, total weekly training duration, total weekly jump contacts, and progression principles will be matched as closely as possible to the traditional concentrated plyometric training intervention. The primary difference between the interventions will be training frequency and the amount of training completed in each session.
Participants assigned to this intervention will continue their regular rope-skipping-specific training and complete an 8-week traditional concentrated plyometric training program. Plyometric training will be performed in two concentrated sessions per week. The exercise content, total weekly training duration, total weekly jump contacts, and progression principles will be matched as closely as possible to the microdosed plyometric training intervention. The primary difference between the interventions will be training frequency and the amount of training completed in each session.
Chengdu College of Arts and Sciences
Chongqing, Chongqing Municipality, China
Change From Baseline in Isokinetic Knee Extensor Total Work at Week 8
Lower-limb muscular endurance will be assessed using an isokinetic dynamometer. Following a standardized warm-up and familiarization procedure, participants will perform 30 consecutive maximal concentric knee-extension contractions with the dominant lower limb at an angular velocity of 180 degrees per second. The total work performed by the knee extensors across all valid repetitions will be recorded and reported in joules (J). Change from baseline will be calculated as the Week 8 value minus the baseline value. Higher values indicate greater lower-limb muscular endurance.
Time frame: Baseline and post-intervention at Week 8
Change From Baseline in Isokinetic Knee Extensor Peak Torque at Week 8
Lower-limb muscle strength will be assessed using an isokinetic dynamometer. Following a standardized warm-up and familiarization procedure, participants will perform maximal concentric knee-extension contractions with the dominant lower limb at an angular velocity of 60 degrees per second. The highest peak torque obtained from the valid repetitions will be recorded and reported in newton-metres (N·m). Change from baseline will be calculated as the Week 8 value minus the baseline value. Higher values indicate greater lower-limb muscle strength.
Time frame: Baseline and post-intervention at Week 8
Change From Baseline in Standing Broad Jump Distance at Week 8
Lower-limb explosive performance will be assessed using the standing broad jump test. Following a standardized warm-up, participants will stand behind the take-off line with both feet parallel and jump forward as far as possible using a simultaneous two-foot take-off and landing. Each participant will complete three valid trials, with an adequate recovery interval between trials. The longest valid horizontal distance from the take-off line to the nearest point of contact on landing will be recorded in metres (m). Change from baseline will be calculated as the Week 8 value minus the baseline value. Higher values indicate better lower-limb explosive performance.
Time frame: Baseline and immediately after the 8-week intervention
Change From Baseline in the Number of Valid Repetitions Completed During the 30-Second Single-Rope Speed Test at Week 8
Rope-skipping-specific performance will be assessed using the 30-second single-rope speed test. Following a standardized warm-up, participants will perform as many valid single-rope skipping repetitions as possible within 30 seconds. One valid repetition will be counted when the rope passes completely under both feet during a successfully completed jump. Repetitions involving rope entanglement, interruption, or unsuccessful rope passage will not be counted. The total number of valid repetitions completed within 30 seconds will be recorded. Change from baseline will be calculated as the Week 8 value minus the baseline value. Higher values indicate better rope-skipping-specific performance.
Time frame: Baseline and immediately after the 8-week intervention
Change From Baseline in Isokinetic Knee Extensor Fatigue Index at Week 8
Lower-limb muscular fatigue will be assessed during the repeated isokinetic knee-extension test performed at an angular velocity of 180 degrees per second. The fatigue index will be calculated using the mean work of the first three and final three valid repetitions according to the following formula: \[(mean work of the first three repetitions - mean work of the final three repetitions) / mean work of the first three repetitions\] × 100. The fatigue index will be reported as a percentage (%). Change from baseline will be calculated as the Week 8 value minus the baseline value. Lower values indicate less muscular fatigue and better muscular endurance.
Time frame: Baseline and immediately after the 8-week intervention
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