Effects of Post-Exercise Recovery Interventions on Visual Analogue Scale Scores, Blood Lactate Concentration, and Isokinetic Muscle Function Following Muscle Fatigue in Amateur Swimmers

High-intensity, repetitive exercise induces metabolic stress and neuromuscular fatigue in skeletal muscle. Muscle fatigue involves both peripheral and central mechanisms, impairing contractile function and increasing pain perception, thereby compromising athletic performance and elevating injury risk. Using a repeated-measures crossover design, eight male amateur swimmers completed five experimental sessions at one-week intervals. Following an isokinetic fatigue protocol, five recovery interventions were applied in randomized order: control, foam roller (FR), vibration foam roller (VFR), whole-body vibration at 12 Hz (WBV-12), and 20 Hz (WBV-20). Outcome measures included visual analogue scale (VAS) scores, blood lactate concentration, and knee extensor peak torque assessed at three time points. Significant main effects of recovery method were observed for VAS scores (F = 2.892, p = .036, η² = 0.248), blood lactate (F = 2.937, p = .034, η² = 0.251), and peak torque (p < .05). Active recovery interventions, particularly vibration-based modalities, were more effective than passive rest. WBV-20 demonstrated the most consistent recovery effects, suggesting its potential as an effective post-exercise recovery strategy.