Effect of low-level laser therapy (808 nm) on skeletal muscle after endurance exercise training in rats

BACKGROUND:

Low-level laser therapy (LLLT) has been demonstrated to be effective inoptimizing skeletal muscle performance in animal experiments and in clinicaltrials. However, little is known about the effects of LLLT on muscle recoveryafter endurance training.

OBJECTIVE:

This study evaluates the effects of low-level laser therapy (LLLT) applied afteran endurance training protocol on biochemical markers and morphology of skeletalmuscle in rats.

METHOD:

Wistar rats were divided into control group (CG), trained group (TG), and trainedand laser irradiated group (TLG). The endurance training was performed on atreadmill, 1 h/day, 5 days/wk, for 8 wk at 60% of the maximal speed reached duringthe maximal effort test (Tmax) and laser irradiation was applied after training.

RESULTS:

Both trained groups showed significant increase in speed compared to the CG. TheTLG demonstrated a significantly reduced lactate level, increased tibialisanterior (TA) fiber cross-section area, and decreased TA fiber density. Myogeninexpression was higher in soleus and TA muscles in both trained groups. Inaddition, LLLT produced myogenin downregulation in the TA muscle of trainedanimals.

CONCLUSION:

These results suggest that LLLT could be an effective therapeutic approach forstimulating recovery during an endurance exercise protocol.