Eccentric Training Cuts Hamstring Injury Risk in Soccer, While Plyometrics Drive Speed Gains
Hamstring strain injuries remain one of the most disruptive problems in soccer, where a single tear can derail selection, reduce match availability, and linger well beyond the acute event. A new systematic review and meta-analysis separated two exercise strategies that are often grouped together in practice but do not appear to behave the same way at the bedside or on the training pitch: eccentric training and plyometric training. The analysis included randomized controlled trials in soccer players aged 13 years or older and searched five databases plus a structured academic corpus from inception to 2026 under PRISMA 2020 methods.
The dataset was substantial for a sports medicine question. Of 705 records screened, 54 trials were ultimately included, giving the pooled estimates a wider evidence base than many injury-prevention studies in team sport. Even so, the most persuasive signal belonged to a narrow set of trials focused specifically on injury incidence rather than performance. In four studies, Nordic hamstring work reduced hamstring-injury incidence by roughly 70%, with a pooled risk ratio of 0.29 and a 95% confidence interval from 0.17 to 0.48.
That is not a subtle shift. It points to a biologically coherent mechanism: repeated high-load lengthening strengthens the hamstring musculotendinous unit in the exact phase of the gait cycle and sprint action when the muscle is most vulnerable to overload. In practical terms, eccentric work appears to raise the tissue’s tolerance for deceleration forces, late-swing braking, and the high strain that often precedes a noncontact injury.
Separate Training Pathways Produced Separate Outcomes
The review did not treat performance and injury prevention as interchangeable endpoints, and that separation sharpened the findings. Plyometric bounding did not reduce hamstring-injury risk, which is important because explosive jumping drills are frequently assumed to confer broad protective effects simply by making athletes faster and more powerful. In this dataset, the injury-prevention signal was specific to eccentric loading rather than to all forms of high-intensity lower-limb training.
Performance outcomes moved in a different direction. Across the pooled studies, training improved vertical jump with an effect size of g = 0.70 and sprint performance with g = 0.75. Those are meaningful athletic gains in a sport where a few hundredths of a second or a small increase in jump height can influence duels, aerial contests, and first-step separation.
The subgroup analysis, however, revealed a more selective pattern. Eccentric training did not significantly improve sprint performance in the available subgroup estimate, where the effect size was g = 0.30 across two trials, and the comparison was underpowered. By contrast, plyometric training improved sprint performance with g = 0.67, and combined programs produced the largest sprint effect at g = 1.02. Sprinting therefore seems to respond better to exercises that train elastic energy return, stretch-shortening behavior, and rapid force transmission than to eccentric work alone.
Strength Gains Favored Eccentric Loading
Eccentric training also increased eccentric knee-flexor strength, with an effect size of g = 0.82. This result fits the known mechanical role of the hamstrings during sprinting and cutting, where the group must absorb force while lengthening rather than merely generate force concentrically. The strength gain matters because injury prevention often depends less on generic conditioning than on whether the muscle can withstand the high-tension demands of sport-specific movement.
A brief clinical interpretation follows directly from the pattern of effects. Eccentric work seems to protect the hamstring and build the force capacity needed to resist injury, while plyometric work seems to develop the speed and power qualities most closely linked to sprint output. Combined programs appear to split the difference, covering both sides of the performance-injury equation rather than forcing coaches to choose one target at the expense of the other.
What Coaches Can Infer from the Evidence Split
For soccer programs, the review argues against treating all lower-limb conditioning as interchangeable. A squad that uses only jumping drills may gain explosiveness without materially reducing hamstring strain risk. A squad that relies only on eccentric drills may lower injury incidence and build strength, yet leave some sprint-specific qualities less developed than with plyometric or mixed training.
The most useful reading of the data is straightforward: Nordic hamstring exercise belongs in injury-prevention programming, while plyometric work has a clearer role in performance development. Combined training deserves attention because it produced strong sprint gains and addresses both tissue resilience and athletic output in the same program design. In a sport with dense fixture schedules and limited recovery windows, the ability to prevent a strain while preserving or improving speed is not an abstract advantage; it is roster availability, match readiness, and training continuity.
The review also leaves some important limits in place. The injury-prevention estimate for eccentric work rested on only four trials, and the sprint subgroup for eccentric training was underpowered. That means the absence of a sprint benefit from eccentric-only programs should not be read as proof of no effect. It simply means the current evidence base is too small to claim a robust performance advantage for eccentric loading alone.
Funding for the research was not provided by an external source, and the authors reported no competing interests. Those disclosures reduce concern about commercial influence, but they do not resolve the central question for practitioners: which training mix best fits a given squad, competition calendar, and injury history. The answer will likely depend on how coaches balance the clear protective effect of eccentric work against the stronger speed and power gains seen with plyometric and combined programs.