Introduction: The aim of this study was to determine whether whole body periodic acceleration (pGz) could improve muscle recovery after unaccustomed eccentric exercise (EE). 

Methods: Downhill treadmill running was used to elicit EE-induced muscle damage in mice, and pGz treatment (480 cycles per minute, 1 h·d -1) was applied daily for 10 d after the initial EE bout (day 0). Every 2 d during the pGz treatment course starting at day 0, we 1) assessed intracellular Ca 2+ and Na + concentrations and membrane potential (as indicators of intracellular ion dysfunction) in vivo in gastrocnemius muscle from anesthetized animals and 2) quantified creatine kinase (CK), tumor necrosis factor α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), interleukin-6 (IL-6), and interleukin-10 (IL-10) concentrations in plasma or muscle lysates (as indicators of muscle damage and inflammation). 

Results: EE significantly increased intracellular Ca 2+ and Na +, CK, TNF-α, MCP-1, IL-6, and IL-10, all of which peaked on day 2 with the exception of IL-10 and declined slowly over 10 d of recovery. pGz treatment after the EE bout mitigated ion dyshomeostasis and expedited recuperation to control values after 6 d of treatment. pGz treatment also accelerated the normalization of CK, TNF-α, MCP-1, and IL-6 while further increasing IL-10 concentrations. The nitric oxide synthase inhibitor L-N G -nitroarginine methyl ester, administered in drinking water before and maintained throughout the treatment course, was sufficient to abrogate the salutary effects of pGz after EE. 

Conclusions: The present study demonstrates whole body periodic acceleration as an effective therapeutic strategy to accelerate muscle recovery after EE-induced skeletal muscle injury, as indicated by a faster normalization of all the studied parameters.