Jump Performance following Foot Muscle Training: Influence of Barefoot versus Shod Exercise.

Foot muscle strength influences jumping performance, but adaptation differences between barefoot and shod training remain unclear. This study compared the effects of an 8-week training program performed barefoot (BARE), shod (SHOD), or without training (CON). Healthy habitually SHOD non-athlete adults (age: 39.0±10.6 y; height: 1.61±0.08 m; body mass: 61.5±9.8 kg) were assigned to BARE (n=19), SHOD (n=17), or CON (n=17) groups. Participants in the training groups performed 60-minute sessions twice weekly. Toe flexor strength, foot arch height, and jump performance were assessed at baseline and weeks 2, 4, 6, and 8. In the BARE group, toe flexor strength increased by 8.3% at week 2 (p≤0.05) and continued to improve through weeks 4-8 (p≤0.01, effect size=1.17), whereas gains in the SHOD group appeared at week 4 and were limited to baseline comparisons. Vertical jump height improved similarly across groups, whereas standing broad jump distance improved in the BARE group after 8 weeks (p≤0.01) and was greater than that in the CON group (p≤0.01, effect size=1.12). These findings suggest that identical barefoot training induces earlier and progressive improvements in foot muscle strength and may contribute to improved forward jump performance.