Strength Training on Muscle Power Output and Neuromuscular Adaptation Among China University Long Jump Athletes

Not Applicable

Completed

• Conditions: Physical Dependence

• Registration Number: NCT06468449
• Lead Sponsor: Rong Wenchao

Brief Summary

The purpose of this study is to investigate the effects of optimal load strength training on the lower limb neuromuscular adaptation of athletes. An anatomical analysis of the vertical jump reveals three phases: the propulsion phase, the flight phase, and the landing phase.

This study is an 8-week randomized controlled trial. After selecting the participants, basic information such as height, weight, age, and years of training experience is collected. Subsequently, a maximal output power test for lower limb squatting is conducted. Participants are then randomly assigned to the speed group, power group, and strength group. The optimal power load for the power group is determined based on the participant maximal output power. Training plans are developed for the traditional group, power group, and strength group. Each training session is organized and supervised by a designated person. Surface electromyography, three-dimensional motion capture systems, and force platforms are used to collect electromyographic and kinetic data of participants during pre-test and post-test vertical jump actions. Electromyography evoked potential instruments and myotonometer are used to collect nerve signals of the tibial nerve (posterior calf) and muscle fiber dimension data of the rectus femoris before and after the experiment. Additionally, static full-range-of-motion vertical jump kinematics and kinetics data are collected before and after the experiment. To ensure the quality and validity of the intervention, the following controls are implemented during the experiment: first, communication with the participants to inform them of the purpose of the study and ensure adherence to the correct movement standards during testing; second, having a designated person responsible for resistance training during the experiment; third, using the same equipment and team for testing to maximize the controllability of the experiment process; fourth, providing verbal encouragement to participants during testing to maximize effort and minimize experimental errors. The aim is to determine the effects of optimal load strength training on improving the lower limb output power during the propulsion phase of the take-off stage in long jump athletes and the underlying neuromuscular adaptation mechanisms.

Detailed Description

In this study, the experimental group conducted 8 weeks of maximum output power strength training, and the control group also conducted 8 weeks of explosive power training (strength combined with speed). The subjects trained twice a week, and each training was not based on time, but on the number of times multiplied by the number of groups. The training load in the 8-week strength training of the experimental group was the load weight corresponding to the maximum output power of the subjects, and the training load in the control group was between 70% and 85% of the maximum strength. In the control group, the entire cycle was divided into three stages, 1-2 weeks: Adaptation period; 3-5 weeks: Enhancement period; 6-8 weeks: Stabilization period; the experimental group had no period division. The equipment for strength training in both the experimental and control groups was the Smith rack. The experimental group used weighted half squat jumps, and the control group used weighted half squat jumps plus knee hug jumps.

Study Timeline

• Study Start: 2024-03-05
• Study First Submitted: 2024-06-03
• Study First Submitted QC: 2024-06-15
• Study First Posted: 2024-06-21
• Primary Completion: 2024-09-27
• Study Completion: 2024-10-05
• Status Verified: 2025-03
• Last Update Submitted: 2025-03-02
• Last Update Posted: 2025-03-05

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Male
• Target Recruitment: 38

Inclusion Criteria

1. Aim for uniformity in various indicators to minimize errors caused by height, weight, and training experience differences.
2. Aim for a 1RM/body weight ratio of around 2.
3. Maintain normal diet and sleep patterns during the training period, and refrain from using supplements such as creatine and protein powder.
4. Male university long jump athletes should be aged ≥18, and they should not have engaged in strength training 48 hours before the baseline testing.

Exclusion Criteria

1. Participants with various visceral diseases and abnormal liver or kidney function are excluded.
2. Those with unhealthy habits are excluded.
3. Participants with caffeine intake within 3 hours before testing are excluded.
4. Individuals who have engaged in high-intensity resistance exercises within the past 24 hours are excluded.
5. Those with lower limb joint injuries (open and closed) in the last 3 months are excluded.
6. Participants with contraindications such as cardiovascular diseases, skin allergies, and hernia are excluded.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SEQUENTIAL

Primary Outcome Measures

Name	Time	Method
Muscle adaptation indicators (Muscle cross-sectional area)	From enrollment to the end of treatment at 8 weeks	Muscle cross-sectional area assessment uses ultrasound to measure the cross-sectional area of the rectus femoris muscle fibers to assess muscle adaptation
Indicators of Neurological Adaptation (H-max/ M-max)	From enrollment to the end of treatment at 8 weeks	This includes the H-max/ M-max. The test was performed using a potential evoked instrument. Among them, M-max refers to the average value of the first ten M-wave amplitude peaks. H-max refers to the maximum value of the H wave observed when the sensory nerve is stimulated at a frequency of 1Hz.
Sports performance indicators (Take-off height)	From enrollment to the end of treatment at 8 weeks	This study used three-dimensional motion capture equipment and a test bench to test the athletes' take-off height before and after the experiment.
Indicators of Neurological Adaptation (M wave amplitude)	From enrollment to the end of treatment at 8 weeks	This includes the M wave amplitude，The test was performed using a potential evoked instrument.
Indicators of Neurological Adaptation （Nerve conduction velocity）	From enrollment to the end of treatment at 8 weeks	Nerve conduction velocity. The test was performed using a potential evoked instrument.
Indicators of Neurological Adaptation （Latency of the H reflex）	From enrollment to the end of treatment at 8 weeks	Latency of the H reflex. The test was performed using a potential evoked instrument.
Sports performance indicators (Vertical jump speed )	From enrollment to the end of treatment at 8 weeks	This study used three-dimensional motion capture equipment and a test bench to test the vertical jump speed of athletes.
Indicators of Neurological Adaptation ( Nerve impulse frequency)	From enrollment to the end of treatment at 8 weeks	This includes nerve impulse frequency，Using wireless electromyography signal collection system
Indicators of Neurological Adaptation（Number of nerve impulses）	From enrollment to the end of treatment at 8 weeks	This includes the number of nerve impulses. Using wireless electromyography signal collection system
Sports performance indicators (Power output)	From enrollment to the end of treatment at 8 weeks	This study used three-dimensional motion capture equipment and a test bench to test the power output of athletes' lower limbs.
Indicators of Neurological Adaptation （presynaptic inhibition）	From enrollment to the end of treatment at 8 weeks	This includes presynaptic inhibition. This value can only be obtained by processing the H reflex amplitude and the M wave amplitude. The presynaptic inhibition calculation formula is: Hmax1Hz = (Ave. H1:H10) / H1 PSI = Hmax1Hz / Mmax.

Trial Locations

Locations (2)

YanShan university; 🇨🇳 QinHuangdao, HeiBei, China

Rong Wenchao; 🇨🇳 Qinhuangdao, HeiBei, China