Comparative Effectiveness of Exercise Interventions for Hamstring Injury Prevention in Football Players: A Systematic Review and Network Meta-analysis
Sports medicine - open · 2026
FIFA 11+ still edges out other hamstring prevention programs in this analysis, but the ranking is low-certainty and no trial has tested it head-to-head against Nordic exercise.
The paper
Systematic review and network meta-analysis of 11 RCTs, n=9,282 football players, comparing exercise-based hamstring injury prevention programs.
What they found
FIFA 11+ was associated with reduced hamstring injury incidence versus usual training (IRR 0.55, 95% CI 0.31-0.98, P-score 0.84), the most consistent effect in the network, while Nordic hamstring exercise showed only a modest, non-significant reduction and FIFA 11 and the bounding exercise program showed no clear benefit.
Study design
PRISMA-aligned systematic review and random-effects network meta-analysis of RCTs (PROSPERO registered), pooling 11 trials and 9,282 football players across five active interventions versus usual training. This is high on the evidence hierarchy by design, but it aggregates a small, heterogeneous, mostly male and partly youth trial base.
Methodology
Searches covered four databases to January 2026 and RoB 2 was applied, but 3 of 11 trials were rated high risk of bias and the remaining 8 as 'some concerns', with none rated low risk, meaning the pooled estimates rest on flawed component trials (unblinded exercise delivery, variable injury definitions, inconsistent exposure and adherence reporting). Critically, the network is largely star-shaped: almost every trial compares an active program against usual training, so rankings between FIFA 11+, NHE and BEP come from indirect comparison rather than head-to-head data, and substantial between-study heterogeneity further weakens confidence in those indirect estimates.
The appraisal
The FIFA 11+ effect is statistically significant but the confidence interval (0.31-0.98) is wide and sits just under the null, spanning anywhere from a large protective effect to almost none, and the authors themselves grade certainty as low to very low. That grading isn't just caution for its own sake: RoB 2 rated three of the eleven trials as high risk of bias and the other eight as having some concerns, so not one trial in the whole network was judged low risk, and between-study heterogeneity was substantial on top of that. The design also cannot support a genuine comparative claim between programs, since there are no direct active-versus-active trials; this is a hypothesis-generating ranking built on indirect evidence, not proof that FIFA 11+ outperforms Nordic-based programs.
The gap
There is no direct trial comparing FIFA 11+ against Nordic hamstring exercise head-to-head, so the apparent ranking could reflect differences in trial quality and populations rather than a true difference in effectiveness. Well-reported trials with consistent injury definitions, exposure and adherence data are needed before this hierarchy can be trusted.
Landmark context
This builds on the original Nordic hamstring exercise trials and the FIFA 11+/11+ Kids injury-prevention literature that established each program's individual benefit against usual training; this NMA is novel in trying to formally rank them against each other, but it does not overturn or replace those foundational single-intervention trials.
What to do Monday
This doesn't justify switching an established Nordic hamstring program to FIFA 11+, or vice versa, on Monday. Keep delivering whichever evidence-based program you already have high adherence with, since the ranking here is low-certainty and not based on direct comparison.
In practice
This sits jointly between physio and S&C, hamstring prevention programming is delivered pitch-side, not in the treatment room. Don't use this NMA as grounds to swap an already-adherent Nordic hamstring programme for FIFA 11+, the apparent edge is low-certainty indirect evidence with no head-to-head trial behind it. Where Nordic compliance is genuinely poor, which is common given how unpopular the exercise is with players, FIFA 11+ is a reasonable evidence-supported programme to reach for instead, on the strength of the largest and most consistent dataset in this review, but frame it to the squad as 'well-supported', not 'proven superior'. One caveat in applying it either way: this review says nothing about combining programmes or about dose, so it's not licence to trim volume or frequency of whatever you're currently delivering well.
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