Acute application of photobiomodulation does not bring important gains for the muscular performance and functionality of diabetic individuals.

Photobiomodulation therapy (PBMT) has been used to improve the physical performance of individuals with advanced age; however, there are no studies in the literature that support the application of light-emitting diode (LED) therapy for the muscular performance of individuals with diabetes mellitus who show a decline in functionality. The aim of the study was to analyze the acute effects of PBMT on strength and functional performance in type 2 diabetic individuals. Sixty-three volunteers were recruited and randomized into five groups: control (C), sham (S), red LED (R), infrared LED (IR), and red LED + infrared LED (R + IR). On the first day, the volunteers were evaluated using the time up and go (TUG), the 6-min walk test (6MWT), and isokinetic dynamometer of the ankle. In the following 3 days, groups R, IR, R + IR, and S returned for application of PBMT bilaterally, with 180 J of energy on each leg. On the fifth day, a reassessment was performed. There was no statistical difference between groups for the variables of the isokinetic dynamometer, TUG, and 6MWT. Analysis of the size of the clinical effect for the isokinetic variables showed that there was no pattern among the effects observed. There is a moderate effect in favor of R, IR, and R + IR in relation to C for the TUG and a moderate effect of R + IR in relation to C for the 6MWT. The PBMT applied for a short period does not bring important gains for the muscular performance and functionality of diabetic individuals.