Eccentric hamstring training (notably the Nordic hamstring exercise) substantially reduces hamstring strain injury rates in athletes who do high-speed running.

In plain English

A hamstring-strengthening move called the Nordic curl cut hamstring tears roughly in half among athletes who sprint and cut. The more often they did it, the better it worked.

Why it works

Eccentric loading at long muscle lengths increases hamstring strength and fascicle length, both of which protect against the late-swing-phase eccentric overload that causes hamstring strains.

What it means in practice

Include Nordic hamstring exercise (or equivalent eccentric work) in strength programs for runners who do tempo, threshold, or interval work at faster paces. 2-3 sessions per week, 3-6 sets of 5-10 reps. Beginners should start with assisted variations due to high eccentric loading.

The evidence

• van Dyk, N., Behan, F.P., Whiteley, R. (2019). Including the Nordic hamstring exercise in injury prevention programmes halves the rate of hamstring injuries: a systematic review and meta-analysis of 8459 athletes. British Journal of Sports Medicine.

  Programs that include the Nordic hamstring exercise reduce hamstring injuries by approximately 51%. Overall risk ratio: 0.49 (95% CI 0.32-0.74, p=0.0008) favoring NHE-inclusive programs. Pooling only the 8 RCTs: RR 0.52 (95% CI 0.32-0.85, p=0.0008). After removing 8 high-risk-of-bias studies: RR 0.55 (95% CI 0.34-0.89, p=0.006). The conclusion holds across multiple sports, age groups, and both sexes. The effect is robust to study-quality sensitivity analysis.

  n=8459

• Andrews, M.H., Shield, A.J., Lichtwark, G.A. et al. (2025). Hamstring Injury Mechanisms and Eccentric Training-Induced Muscle Adaptations: Current Insights and Future Directions. Sports Medicine.

  Eccentric training programs that increase knee flexor strength effectively reduce risk of hamstring strain injuries, especially with high adherence. Current research overly focuses on architectural changes (resting fascicle lengthening) rather than functional behavior. Non-contractile and neural adaptations are under-researched.

Why we call confidence high

Van Dyk 2019 meta-analysis showed Nordic hamstring exercise reduced injury risk by ~50%. Andrews 2025 narrative review in Sports Medicine confirms direction. Effect is well-established in football; extrapolation to recreational runners is reasonable but evidence base is football-heavy.

Where it applies

Adult athletes who do high-speed running including soccer, rugby, and faster-paced distance running.

Does not apply to: recreational joggers who never run faster than aerobic pace; runners with current acute hamstring symptoms.