Original Article

Lasers in Medical Science

, Volume 27, Issue 1, pp 231-236

First online:

Low-level laser therapy (LLLT) in human progressive-intensity running: effects on exercise performance, skeletal muscle status, and oxidative stress

  • Thiago De MarchiAffiliated withLaboratory of Oxidative Stress and Antioxidants, Institute of Biotechnology, University of Caxias do SulSports Medicine Institute and Laboratory of Human Movement, University of Caxias do Sul
  • , Ernesto Cesar Pinto Leal JuniorAffiliated withPost Graduate Program in Rehabilitation Sciences, Nove de Julho University (UNINOVE)
  • , Celiana BortoliAffiliated withLaboratory of Oxidative Stress and Antioxidants, Institute of Biotechnology, University of Caxias do Sul
  • , Shaiane Silva TomazoniAffiliated withLaboratory of Pharmacology and Experimental Therapeutics, Institute of Biomedical Sciences (ICB), University of São Paulo
  • , Rodrigo Álvaro Brandão Lopes-MartinsAffiliated withPost Graduate Program in Rehabilitation Sciences, Nove de Julho University (UNINOVE)Laboratory of Pharmacology and Experimental Therapeutics, Institute of Biomedical Sciences (ICB), University of São Paulo
  • , Mirian SalvadorAffiliated withLaboratory of Oxidative Stress and Antioxidants, Institute of Biotechnology, University of Caxias do Sul Email author 

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Abstract

The aim of this work was to evaluate the effects of low-level laser therapy (LLLT) on exercise performance, oxidative stress, and muscle status in humans. A randomized double-blind placebo-controlled crossover trial was performed with 22 untrained male volunteers. LLLT (810 nm, 200 mW, 30 J in each site, 30 s of irradiation in each site) using a multi-diode cluster (with five spots - 6 J from each spot) at 12 sites of each lower limb (six in quadriceps, four in hamstrings, and two in gastrocnemius) was performed 5 min before a standardized progressive-intensity running protocol on a motor-drive treadmill until exhaustion. We analyzed exercise performance (VO2 max, time to exhaustion, aerobic threshold and anaerobic threshold), levels of oxidative damage to lipids and proteins, the activities of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT), and the markers of muscle damage creatine kinase (CK) and lactate dehydrogenase (LDH). Compared to placebo, active LLLT significantly increased exercise performance (VO2 max p = 0.01; time to exhaustion, p = 0.04) without changing the aerobic and anaerobic thresholds. LLLT also decreased post-exercise lipid (p = 0.0001) and protein (p = 0.0230) damages, as well as the activities of SOD (p = 0.0034), CK (p = 0.0001) and LDH (p = 0.0001) enzymes. LLLT application was not able to modulate CAT activity. The use of LLLT before progressive-intensity running exercise increases exercise performance, decreases exercise-induced oxidative stress and muscle damage, suggesting that the modulation of the redox system by LLLT could be related to the delay in skeletal muscle fatigue observed after the use of LLLT.

Keywords

LLLT Progressive-intensity exercise Oxidative stress Muscle damage