Age-Specific Signatures of Exercise-Induced Muscle Damage and the Neuromodulatory Efficacy of Standardized Foam Rolling

PURPOSE: This study aimed to elucidate age-specific mechanical and physiological recovery kinetics following maximal eccentric exercise and evaluate the efficacy of force-plate-standardized foam rolling (FR) intervention in mitigating myofascial stiffening and systemic biomarker efflux across young and middle-aged populations. METHODS: Thirty-two physically active males were stratified into young (20-30 years) and middle-aged (40-55 years) groups. Using a randomized, counterbalanced crossover design, participants performed a high-volume, maximal eccentric knee protocol (20 sets, 236 total repetitions across varying velocities) followed by either passive recovery (control) or standardized FR. Mechanical properties via ultrasound shear wave elastography, systemic biomarkers, creatine kinase (CK) and lactate dehydrogenase (LDH), and perceived soreness were assessed at baseline, 0 h, 24 h, 48 h, and 72 h post-exercise. RESULTS: In control, both groups exhibited profound delayed-onset CK elevation peaking at 72 h. Counterintuitively, while the middle-aged group generated significantly greater absolute mechanical work and peak torque during the exercise protocol, it was the young group that demonstrated massively higher secondary CK and LDH efflux. The middle-aged group exhibited immediate sarcolemma fragility (elevated CK at 0 h) and structural resistance to FR-induced tissue softening. Despite distinct damage signatures, standardized FR effectively blunted secondary CK efflux, eradicated age-related disparities in LDH magnitude, and universally alleviated perceived soreness. Notably, objective mechanical restoration was not significantly correlated with subjective pain reduction. CONCLUSIONS: Biological aging and maximal eccentric exercise interacted to produce distinct damage signatures. Aging myofascial tissue appeared to provide a "mechanical shield" that protected against massive delayed-onset structural disruption despite sustaining greater absolute mechanical work, albeit exhibiting immediate membrane fragility and localized mechanical recalcitrance. Nevertheless, standardized FR serves as a potent physiological homogenizer and neuromodulator, effectively blunting secondary damage and alleviating soreness across demographics, independent of absolute mechanical tissue softening.