Low-level phototherapy to improve exercise capacity and muscle performance: a systematic review and meta-analysis

Abstract

The aim of this study was to evaluate the effectiveness of pre-exercise low-level phototherapy (Light-Emitting Diode therapy [LEDtherapy] or Light Amplification by Stimulate Emission of Radiation therapy [LASERtherapy]) in increasing exercise capacity and muscle performance of people undergoing exercise when compared to placebo treatment. Randomized controlled trials and crossover studies were sought on CENTRAL, MEDLINE, EMBASE, SciELO, PEDro and LILACS from its inception up to February 2015. References lists of included studies were sought for additional relevant research. Two authors independently extracted data on study design, treatment parameters, exercise capacity (number of repetitions, time to exhaustion, blood lactate concentration and lactate dehydrogenase activity) and muscle performance (torque, power and strength) using an structured table. Agreement should be reached by consensus or by a third reviewer. Sixteen studies involving 297 participants were included. Improvement of number of repetitions (mean difference [MD] [95 % confidence interval] = 3.51 repetitions [0.65-6.37]; P = 0.02), delay in time to exhaustion (MD = 4.01 s [2.10-5.91]; P < 0.0001), reduction in lactate levels (MD = 0.34 mmol/L [0.19-0.48]; P < 0.00001) and increased peak torque (MD = 21.51 Nm [10.01-33.01]; P < 0.00001) were observed when LASERtherapy was applied. LEDtherapy meta-analyses were performed with two studies and retrieved no between-group statistically significant difference in power, lactate levels or time to exhaustion. Although our results suggest that LASERtherapy is effective in improving skeletal muscle exercise capacity, the quality of the current evidence is limited.

Effect of Low-Level Laser Therapy and Strength Training Protocol on Hand Grip by Dynamometry

“…Thus, our study is unprecedented with respect to the evaluation of the muscles involved in handgrip activity and enables the development of new studies relating phototherapy with strength training and its application in various lesions that may lead to decreased strength in this segment, for example, as a result of radius fractures, injuries of the flexor tendons of fingers, and hand complex lesions. Nampo et al, 28 investigated if LLLT improves exercise capacity and muscle performance. The review used sixteen studies that analyzed pre exercise LLLT or LEDT irradiation effects with different parameters.…”

Phototherapy in the blue range of visible spectrum: the possibilities of optimization of the functional state of the cardiorespiratory system in humans under extreme conditions

“…the use of electromagnetic waves of the optical (and near optical) range for therapeutic and preventive purposes, is increasingly introduced in the armory of non-drug methods of influence on the human body status. For instance, the effects of red (630-700 nm) and infrared (800-1200 nm) spectrum wavelengths are widely used in sport medicine for improving physical performance and facilitation of the recovery processes in different muscle groups [7,9,17]. It is believed that phototherapy with the use of long-wave sources best suits for affecting internal structures, including the muscle tissue, because these waves can penetrate up to 10 mm deep into the body [10].…”

Efeito da terapia de fotobiomodulação por Diodo Emissor de Luz (LED) nas capacidades de força e resistência de atletas de ciclismo

“…A diminuição do tempo até a exaustão, diminuição do estresse oxidativo e diminuição dos biomarcadores de dano muscular, também são respostas associadas à aplicação da fototerapia como pré-condicionamento muscular. (Nampo et al, 2016;De Paiva et al, 2016;De Marchi et al, 2017). Os estudos de Lanferdini et al, (2018) são, um dos únicos e os mais recentes quanto à aplicação da terapia por fotobiomodulação em atletas de ciclismo.…”

“…A partir desses mecanismos, é possível observar benefícios em uma gama de desfechos discutidos em revisões sistemáticas recentes, nas quais resultados promissores quanto ao aumento de força muscular (Ferraresi, Huang e Hamblin, 2016), aumento do tempo até exaustão, diminuição da fadiga e diminuição nos níveis de lactato sanguíneo (Leal Junior et al, 2015;Nampo et al, 2016)…”