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

Effects of Optimal Load Strength Training on Muscle Power Output and Neuromuscular Adaptation During Takeoff Among China University Long Jump Athletes

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.

Study Overview

• Status: Completed
• Conditions: Physical Dependence
• Intervention / Treatment: Other: Lower limb power output training; Other: Force Combined Speed training

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 Type: Interventional
• Enrollment (Actual): 38
• Phase: Not Applicable

Contacts and Locations

Study Locations

• China
  • HeiBei
    • QinHuangdao, HeiBei, China, 066004
      • YanShan university
    • Qinhuangdao, HeiBei, China, 066400
      • Rong Wenchao

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

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 Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Sequential Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Experimental Group：power output; by identifying the optimal load at which the athlete achieves the highest power output. The training program is then tailored based on these measurements, ensuring that the athlete trains at the load that maximizes their power output. This approach allows for more efficient and effective strength training, potentially leading to improved athletic performance. Throughout the training period, the VBT equipment continuously monitors the athlete's performance, providing real-time feedback and allowing for adjustments to the load as the athlete's strength and power improve. The goal is to enhance neuromuscular adaptations and optimize the athlete's power development, particularly during explosive movements like the vertical jump and long jump.	Other: Lower limb power output training; Lower limb power output training content: Half squat up squat: 70%1R (6 repetitions × 5sets) + 5 knees jumps × 5 sets with an interval of 90 seconds；
Experimental: Control Group:speed combined force; Speed combined with strength training is designed to enhance the explosive power of long jumpers' lower limbs. This involves using maximum strength barbell squats and knee jumps to develop athletes' maximum strength and improve the speed of their neural contractions. Additionally, plyometric exercises and sprint drills are incorporated to further boost explosive power and coordination. This comprehensive training approach aims to optimize both the force and velocity aspects of power, leading to better overall performance in explosive movements critical for long jump success. Regular assessments and adjustments ensure that training loads are appropriate and effective for each athlete's progress.	Other: Force Combined Speed training; Lower limb Force Combined Speed training content: Rapid half squat : Optimal load (6 sets × 7 repetitions). Rest intervals between sets range from 2 to 5 minutes.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Indicators of Neurological Adaptation（Number of nerve impulses）	This includes the number of nerve impulses. Using wireless electromyography signal collection system	From enrollment to the end of treatment at 8 weeks
Muscle adaptation indicators (Muscle cross-sectional area)	Muscle cross-sectional area assessment uses ultrasound to measure the cross-sectional area of the rectus femoris muscle fibers to assess muscle adaptation	From enrollment to the end of treatment at 8 weeks
Sports performance indicators (Vertical jump speed )	This study used three-dimensional motion capture equipment and a test bench to test the vertical jump speed of athletes.	From enrollment to the end of treatment at 8 weeks
Sports performance indicators (Power output)	This study used three-dimensional motion capture equipment and a test bench to test the power output of athletes' lower limbs.	From enrollment to the end of treatment at 8 weeks
Sports performance indicators (Take-off height)	This study used three-dimensional motion capture equipment and a test bench to test the athletes' take-off height before and after the experiment.	From enrollment to the end of treatment at 8 weeks
Indicators of Neurological Adaptation ( Nerve impulse frequency)	This includes nerve impulse frequency，Using wireless electromyography signal collection system	From enrollment to the end of treatment at 8 weeks
Indicators of Neurological Adaptation (M wave amplitude)	This includes the M wave amplitude，The test was performed using a potential evoked instrument.	From enrollment to the end of treatment at 8 weeks
Indicators of Neurological Adaptation (H-max/ M-max)	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.	From enrollment to the end of treatment at 8 weeks
Indicators of Neurological Adaptation （Nerve conduction velocity）	Nerve conduction velocity. The test was performed using a potential evoked instrument.	From enrollment to the end of treatment at 8 weeks
Indicators of Neurological Adaptation （Latency of the H reflex）	Latency of the H reflex. The test was performed using a potential evoked instrument.	From enrollment to the end of treatment at 8 weeks
Indicators of Neurological Adaptation （presynaptic inhibition）	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.	From enrollment to the end of treatment at 8 weeks

Collaborators and Investigators

• Sponsor: Rong Wenchao
• Investigators: Principal Investigator: wenchao rong, Ph.D, University Putra Malaysia

Publications and helpful links

General Publications

• Sabido R, Hernandez-Davo JL, Botella J, Moya M. Effects of 4-Week Training Intervention with Unknown Loads on Power Output Performance and Throwing Velocity in Junior Team Handball Players. PLoS One. 2016 Jun 16;11(6):e0157648. doi: 10.1371/journal.pone.0157648. eCollection 2016.

Helpful Links

• Related Info

Study record dates

Study Major Dates

• Study Start (Actual): March 5, 2024
• Primary Completion (Actual): September 27, 2024
• Study Completion (Actual): October 5, 2024

Study Registration Dates

• First Submitted: June 3, 2024
• First Submitted That Met QC Criteria: June 15, 2024
• First Posted (Actual): June 21, 2024

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: March 2, 2025
• Last Verified: March 1, 2025

More Information

Terms related to this study

• Keywords: power output; Optimal load strength training;; neuromuscular adaptation;; long jumper
• Other Study ID Numbers: 2024Y004

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Since this is my doctoral thesis experiment, I won't share it until I graduate.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No