Acute neuromuscular and performance responses to Nordic hamstring exercises completed before or after football training

ABSTRACT

The optimal scheduling of Nordic Hamstring exercises (NHEs) relative to football training sessions is unknown. We examined the acute neuromuscular and performance responses to NHE undertaken either before (BT) or after (AT) simulated football training. Twelve amateur players performed six sets of five repetitions of the NHE either before or after 60 min of standardised football-specific exercise (SAFT⁶⁰). Surface electromyography signals (EMG) of the hamstring muscles were recorded during both the NHE, and maximum eccentric actions of the knee flexors (0.52 rad · s^–1) performed before and after the NHE programme, and at 15 min intervals during SAFT⁶⁰. Ten-metre sprint times were recorded on three occasions during each 15 min SAFT⁶⁰ segment. Greater eccentric hamstring fatigue following the NHE programme was observed in BT versus AT (19.8 %; very likely small effect), which was particularly apparent in the latter range of knee flexion (0–15°; 39.6%; likely moderate effect), and synonymous with hamstring EMG declines (likely small–likely moderate effects). Performing NHE BT attenuated sprint performance declines (2.0–3.2%; likely small effects), but decreased eccentric hamstring peak torque (–14.1 to –18.9%; likely small effects) during football-specific exercise. Performing NHE prior to football training reduces eccentric hamstring strength and may exacerbate hamstring injury risk.

KEYWORDS:

• Hamstring strain
• injury prevention
• eccentric strength
• scheduling

Acknowledgements

The authors would like to thank Matthew Stewart and Benjamin Gonano for their assistance with data collection, and the players for their participation in the study.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the NSW Sports Research and Injury Prevention Scheme.