Low level laser therapy before eccentric exercise reduces muscle damage markers in humans

• Published in: European journal of applied physiology 2010-11, Vol.110 (4), p.789-796
• Main Authors: Baroni, Bruno Manfredini, Leal Junior, Ernesto Cesar Pinto, De Marchi, Thiago, Lopes, André Luiz, Salvador, Mirian, Vaz, Marco Aurélio
• Format: Article
• Language: English
• Subjects: Adult; Biological and medical sciences; Biomarkers - blood; Biomedical and Life Sciences; Biomedicine; Biopsy; Creatine Kinase - blood; Dehydrogenases; Exercise; Exercise - physiology; Fundamental and applied biological sciences. Psychology; Health care; Human Physiology; Humans; Kinases; Knee Joint - physiology; L-Lactate Dehydrogenase - blood; Lasers; Light therapy; Low-Level Light Therapy - methods; Male; Muscle Contraction - physiology; Muscle function; Muscle, Skeletal - injuries; Muscle, Skeletal - metabolism; Muscle, Skeletal - radiation effects; Occupational Medicine/Industrial Medicine; Original Article; Pain - prevention & control; Physical fitness; Proteins; Sports Medicine; Vertebrates: body movement. Posture. Locomotion. Flight. Swimming. Physical exercise. Rest. Sports; Young Adult
• ISSN: 1439-6319; 1439-6327
• DOI: 10.1007/s00421-010-1562-z

The purpose of the present study was to determine the effect of low level laser therapy (LLLT) treatment before knee extensor eccentric exercise on indirect markers of muscle damage. Thirty-six healthy men were randomized in LLLT group ( n  = 18) and placebo group ( n  = 18). After LLLT or placebo treatment, subjects performed 75 maximal knee extensors eccentric contractions (five sets of 15 repetitions; velocity = 60° seg −1 ; range of motion = 60°). Muscle soreness (visual analogue scale—VAS), lactate dehydrogenase (LDH) and creatine kinase (CK) levels were measured prior to exercise, and 24 and 48 h after exercise. Muscle function (maximal voluntary contraction—MVC) was measured before exercise, immediately after, and 24 and 48 h post-exercise. Groups had no difference on kineanthropometric characteristics and on eccentric exercise performance. They also presented similar baseline values of VAS (0.00 mm for LLLT and placebo groups), LDH (LLLT = 186 IU/l; placebo = 183 IU/l), CK (LLLT = 145 IU/l; placebo = 155 IU/l) and MVC (LLLT = 293 Nm; placebo = 284 Nm). VAS data did not show group by time interaction ( P  = 0.066). In the other outcomes, LLLT group presented (1) smaller increase on LDH values 48 h post-exercise (LLLT = 366 IU/l; placebo = 484 IU/l; P  = 0.017); (2) smaller increase on CK values 24 h (LLLT = 272 IU/l; placebo = 498 IU/l; P  = 0.020) and 48 h (LLLT = 436 IU/l; placebo = 1328 IU/l; P