Eccentric vs. plyometric training for hamstring health in soccer: a systematic review and meta-analysis of injury prevention and athletic performance

Hamstring strain injuries are the most burdensome muscle injuries in soccer, yet eccentric and plyometric training are typically studied in isolation — the former for injury prevention, the latter for performance. We systematically reviewed randomized controlled trials of eccentric, plyometric, or combined training versus control in soccer players aged 13 years or older, searching five databases and a structured academic corpus from inception to 2026 and reporting according to PRISMA 2020. Of 705 records, 54 trials were included. Hamstring-injury risk was pooled as a random-effects risk ratio, and performance outcomes as change-from-baseline standardized mean differences, with subgroup analyses by intervention type. Eccentric (Nordic hamstring) training reduced hamstring-injury incidence by approximately 70% (4 trials; risk ratio 0.29, 95% CI 0.17–0.48), whereas plyometric bounding did not. Training improved vertical jump (g = 0.70) and sprint (g = 0.75); however, in subgroup analysis eccentric training did not significantly improve sprint (g = 0.30; two trials, underpowered), while plyometric (g = 0.67) and combined (g = 1.02) programs did. Eccentric training increased eccentric knee-flexor strength (g = 0.82). These effects are complementary: eccentric training protects the hamstring and builds strength, plyometric training builds speed and power, and combining the two addresses both.