Effects of Foam Rolling Duration on Tissue Stiffness and Perfusion: A Randomized Cross-Over Trial

Despite its beneficial effects on flexibility and muscle soreness, there is still conflicting evidence regarding dose-response relationships and underlying mechanisms of foam rolling (FR). This study aimed to investigate the impact of different FR protocols on tissue perfusion and tissue stiffness. In a randomized crossover trial, two FR protocols (2x1 min, 2x3 min) were applied to the right anterior thigh of twenty healthy volunteers (11 females, 25 ± 4 years). Tissue perfusion (near infrared spectroscopy, NIRS) and stiffness (Tensiomyography, TMG and Myotonometry, MMT) were assessed before and after FR application. Variance analyses revealed a significant interaction of FR duration and tissue perfusion (F_[1,19] = 7.098, p = 0.015). Local blood flow increased significantly from pre to post test (F_[1,19] = 7.589, p = 0.013), being higher (Δ +9.7%) in the long-FR condition than in the short-FR condition (Δ +2.8%). Tissue stiffness (MMT) showed significant main effects for time (F_[1,19] = 12.074, p = 0.003) and condition (F_[1,19] = 7.165, p = 0.015) with decreases after short-FR (Δ -1.6%) and long-FR condition (Δ -1.9%). However, there was no time*dose-interaction (F_[1,19] = 0.018, p = 0.895). No differences were found for TMG (p > 0.05). FR-induced changes failed to exceed the minimal detectable change threshold (MDC). Our data suggest that increased blood flow and altered tissue stiffness may mediate the effects of FR although statistical MDC thresholds were not achieved. Longer FR durations seem to be more beneficial for perfusion which is of interest for exercise professionals designing warm-up and cool-down regimes. Further research is needed to understand probable effects on parasympathetic outcomes representing systemic physiological responses to locally applied FR stimulations.