Eccentric Training Effects on Hamstrings Structure, Strength, and Sprint Performance

Not Applicable

Completed

• Conditions: Running; Elastography; Healthy; Exercise Training; Sport; Ultrasound Imaging
• Interventions: Diagnostic Test: Ultrasound imaging; Other: Hamstring Eccentric Strength Testing; Other: Maximal 60 m Sprint; Other: Romanian Deadlift; Other: Nordic hamstring exercise

• Registration Number: NCT05455346
• Lead Sponsor: University of Wisconsin, Madison

Brief Summary

The overall goal of this study is to investigate the effects of a 6-week training program between two hamstring exercises-the Romanian deadlift (RDL) and the Nordic hamstring exercise (NHE)-on hamstring strain injury risk factors and sprint performance.

Detailed Description

Prior to the intervention, participants will report to the lab on one occasion for baseline assessments. During the baseline visit, a) regional measures of biceps femoris long head fascicle length, pennation angle, muscle thickness, and anatomical cross-sectional area will be determined using ultrasound, b) baseline NHE strength and 3RM for the RDL will be determined, and c) maximal 60 m sprint performance will be measured.

Participants will be randomly assigned to either the RDL or NHE. After randomization, each participant will undergo the 6 week intervention program based upon their group allocation. Exercises will be performed using a 6 second eccentric (i.e., lowering) contraction.

Following the 6 week intervention, participants would return to the lab for post-intervention assessments of regional hamstring morphology and architecture and sprint testing, which would be carried out in the same manner as baseline assessments. Since fascicle length changes are known to return to baseline values within 2 weeks after the cessation of eccentric training, participants will be asked to return to the lab following a 2 week detraining period where final imaging, strength, and sprint performance assessments will be determined.

Study Timeline

• Study First Submitted: 2022-07-07
• Study First Submitted QC: 2022-07-07
• Study First Posted: 2022-07-13
• Study Start: 2022-12-02
• Status Verified: 2023-12
• Primary Completion: 2023-12-08
• Study Completion: 2023-12-08
• Last Update Submitted: 2023-12-20
• Last Update Posted: 2023-12-21

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 32

Inclusion Criteria

• 18-25 years of age
• Have >6 months experience in resistance training

Exclusion Criteria

• History of hamstring strain injury within the last 12 months
• History of lower extremity surgery
• Current musculoskeletal injury to the lower extremity
• Females who are currently pregnant
• Individuals who indicate they are unwilling to refrain from novel outside training activities
• Individuals who do not complete 75% (9 out of 12) of the training sessions

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Romanian Deadlift	Romanian Deadlift	The training intervention groups will undergo the same program with the only difference being the interventional hamstring exercise. The program will consist of a 2-week acclimatization period followed by 4-weeks of progressive training. The RDL will be performed with a 6 second eccentric component with the athlete returning to the start position with a maximal concentric hip extension.
Nordic Hamstring Exercise	Ultrasound imaging	The training intervention groups will undergo the same program with the only difference being the interventional hamstring exercise. The program will consist of a 2-week acclimatization period followed by 4-weeks of progressive training. During the acclimatization period, the relative intensity will be lower compared to the 4-week progressive training to ensure each participant performs the exercise with proper technique. During the subsequent progressive training weeks, the participants will perform the NHE without the bands.
Romanian Deadlift	Ultrasound imaging	The training intervention groups will undergo the same program with the only difference being the interventional hamstring exercise. The program will consist of a 2-week acclimatization period followed by 4-weeks of progressive training. The RDL will be performed with a 6 second eccentric component with the athlete returning to the start position with a maximal concentric hip extension.
Romanian Deadlift	Hamstring Eccentric Strength Testing	The training intervention groups will undergo the same program with the only difference being the interventional hamstring exercise. The program will consist of a 2-week acclimatization period followed by 4-weeks of progressive training. The RDL will be performed with a 6 second eccentric component with the athlete returning to the start position with a maximal concentric hip extension.
Romanian Deadlift	Maximal 60 m Sprint	The training intervention groups will undergo the same program with the only difference being the interventional hamstring exercise. The program will consist of a 2-week acclimatization period followed by 4-weeks of progressive training. The RDL will be performed with a 6 second eccentric component with the athlete returning to the start position with a maximal concentric hip extension.
Nordic Hamstring Exercise	Maximal 60 m Sprint	The training intervention groups will undergo the same program with the only difference being the interventional hamstring exercise. The program will consist of a 2-week acclimatization period followed by 4-weeks of progressive training. During the acclimatization period, the relative intensity will be lower compared to the 4-week progressive training to ensure each participant performs the exercise with proper technique. During the subsequent progressive training weeks, the participants will perform the NHE without the bands.
Nordic Hamstring Exercise	Hamstring Eccentric Strength Testing	The training intervention groups will undergo the same program with the only difference being the interventional hamstring exercise. The program will consist of a 2-week acclimatization period followed by 4-weeks of progressive training. During the acclimatization period, the relative intensity will be lower compared to the 4-week progressive training to ensure each participant performs the exercise with proper technique. During the subsequent progressive training weeks, the participants will perform the NHE without the bands.
Nordic Hamstring Exercise	Nordic hamstring exercise	The training intervention groups will undergo the same program with the only difference being the interventional hamstring exercise. The program will consist of a 2-week acclimatization period followed by 4-weeks of progressive training. During the acclimatization period, the relative intensity will be lower compared to the 4-week progressive training to ensure each participant performs the exercise with proper technique. During the subsequent progressive training weeks, the participants will perform the NHE without the bands.

Primary Outcome Measures

Name	Time	Method
Biceps femoris long head fascicle length	Post 2 week de-training (8 weeks)

Secondary Outcome Measures

Name	Time	Method
Biceps femoris long head anatomical cross sectional area	Baseline, Post-intervention (6 weeks), Post 2 week de-training (8 weeks)
Romanian deadlift (RDL) 3-repetition maximal strength	Baseline, Post-intervention (6 weeks), Post 2 week de-training (8 weeks)	Maximum weight lifted for 3 repetitions during the RDL
Nordic hamstring exercise (NHE) maximal strength	Baseline, Post-intervention (6 weeks), Post 2 week de-training (8 weeks)	Maximal eccentric force measured by Nordbord device during NHE
Maximal 60 m sprint times	Baseline, Post-intervention (6 weeks), Post 2 week de-training (8 weeks)	Fastest 60 m sprint times with interval split times
Biceps femoris long head muscle thickness	Baseline, Post-intervention (6 weeks), Post 2 week de-training (8 weeks)
Biceps femoris long head pennation angle	Baseline, Post-intervention (6 weeks), Post 2 week de-training (8 weeks)

Trial Locations

Locations (1)

University of Wisconsin; 🇺🇸 Madison, Wisconsin, United States