Dose-Response Relationship for Strength Gains From Nordic Hamstring Exercise: A Systematic Review, Meta-Analysis, and...

Area of Science:

• Sports Science
• Exercise Physiology
• Strength and Conditioning

Background:

• The Nordic hamstring exercise (NHE) is widely used to enhance hamstring muscle strength.
• Understanding the optimal training volume for NHE is crucial for maximizing strength gains and preventing injury.

Purpose of the Study:

• To systematically review and meta-analyze the effects of NHE on eccentric, concentric, and isometric strength.
• To investigate the dose-response relationship between NHE training volume and strength improvements.
• To provide evidence-based recommendations for NHE training volume.

Main Methods:

• A systematic search of 6 databases identified 42 eligible studies.
• Meta-analysis and meta-regression were used to analyze data from studies with varying NHE protocols.
• Studies included participants with diverse conditioning levels and training experience.

Main Results:

• NHE training significantly improved eccentric NHE strength (ES=0.98) and eccentric isokinetic strength (ES=0.52).
• Concentric isokinetic strength also increased (ES=0.42), but isometric strength showed no significant change (ES=0.12).
• No clear association was found between strength gains and training volume variables (duration, frequency, sets, repetitions).

Conclusions:

• NHE is effective for improving eccentric and concentric hamstring strength.
• A weekly volume of 29-64 NHE repetitions, distributed over 2-3 sessions, is likely sufficient for meaningful strength gains, particularly for novices.
• High training volumes are not necessary in the initial 6-8 weeks of NHE training for inexperienced individuals.