Hamstring injury prevention: what 11 trials found

In a 2026 network meta-analysis of 11 randomised trials and 9,282 football players, the FIFA 11+ program had an estimated hamstring injury incidence rate ratio of 0.55 (95% CI 0.31 to 0.98) versus usual training. The Nordic hamstring exercise had an estimate of 0.78 with a confidence interval (0.34 to 1.78) wide enough to include no effect. The authors rated the certainty of the evidence as low to very low.

What did the hamstring injury prevention network meta-analysis find?

Hong et al., Sports Medicine Open 2026 compared several exercise programs at once. A network meta-analysis links trials through a shared comparator, here usual training, and estimates each program against it.

Against usual training, the incidence rate ratios were 0.55 (95% CI 0.31 to 0.98) for FIFA 11+ and 0.43 (0.08 to 2.32) for FIFA 11+ Kids, an imprecise estimate. The Nordic hamstring exercise was 0.78 (0.34 to 1.78). FIFA 11 was 0.99 (0.82 to 1.19) and a bounding exercise program was 1.18 (0.70 to 1.99), neither showing a clear benefit.

The FIFA 11+ interval runs from a large reduction to a value just under 1, so even the most favourable result is imprecise.

How certain is the evidence on hamstring injury prevention?

The authors rated certainty as low for FIFA 11+ and FIFA 11 and very low for FIFA 11+ Kids, the Nordic hamstring exercise and the bounding program, citing clinical and methodological heterogeneity and sparse direct evidence. The network was largely star-shaped, with most evidence comparing a program against usual training, so differences between programs are mostly indirect.

A wide interval that includes 1 means the pooled data cannot separate a benefit from no effect. It is an inconclusive result, not a demonstration that the exercise does not work. The authors call the ranking a low-to-very-low-certainty, population-level summary, not a basis for firm recommendations.

The trials studied football players, so the estimates say little about other sports or about any one athlete. Population-level summaries and individual patterns are different things, a distinction explored in our post on lab ranges and personal baselines.

The bottom line

• In 11 randomised trials and 9,282 football players, FIFA 11+ had an estimated hamstring injury rate ratio of 0.55 (95% CI 0.31 to 0.98) versus usual training.
• The Nordic hamstring exercise estimate was 0.78 (95% CI 0.34 to 1.78), inconclusive rather than negative.
• Certainty was low or very low across the main comparisons, and most evidence compared a program with usual training, not one program with another.