This study aimed to determine the effectiveness of photobiomodulation therapy (PBMT) and cryotherapy, in isolated and combined forms, as muscle recovery techniques after muscle fatigue-inducing protocol. Forty volunteers were randomly divided into five groups: a placebo group (PG); a PBMT group (PBMT); a cryotherapy group (CG); a cryotherapy-PBMT group (CPG); and a PBMT-cryotherapy group (PCG). All subjects performed four sessions at 24-h intervals, during which they submitted to isometric assessment (MVC) and blood collection in the pre-exercise period, and 5 and 60 min post-exercise, while the muscle fatigue induction protocol occurred after the pre-exercise collections. In the remaining sessions performed 24, 48, and 72 h later, only blood collections and MVCs were performed. A single treatment with PBMT and/or cryotherapy was applied after only 2 min of completing the post-5-min MVC test at the first session. In the intragroup comparison, it was found that exercise led to a significant decrease (p < 0.05) in the production of MVC in all groups. Comparing the results of MVCs between groups, we observed significant increases in the MVC capacity of the PBMT, CPG, and PCG volunteers in comparison with both PG and CG (p < 0.05). We observed a significant decrease in the concentrations of the biochemical markers of oxidative damage (TBARS and PC) in all groups and muscle damage (creatine kinase-CK) in the PBMT, PCG, and CPG compared with the PG (p < 0.01). The clinical impact of these findings is clear because they demonstrate that the use of phototherapy is more effective than the use of cryotherapy for muscle recovery, additionally cryotherapy decreases PBMT efficacy.
Keywords: Cryotherapy; High-intensity exercise; Muscle damage; Oxidative stress; Phototherapy.