Department of Physical Therapy, Universidade do Sagrado Coração (USC), Bauru, Brazil.
Laboratory of Biophotonics and Exercise Performance, Universidade Brasil, Sao Paulo, Brazil.
Photobiomodul Photomed Laser Surg. 2020 Dec;38(12):750-757. doi: 10.1089/photob.2020.4813. Epub 2020 Nov 23.
Photobiomodulation therapy (PBMT) by lasers or light-emitting diodes (LEDs) has been used in the last two decades to increase muscle performance in humans. The main findings of PBMT on muscle performance are increment in torque and number of muscle contractions, and fatigue resistance in high-intensity exercises. Although there are suggested light energies to be followed, the literature has also pointed out to a possible time-response of PBMT to increase exercise performance and recovery in humans. To investigate the possible time-response of PBMT by LEDs to increase muscle performance in young men regarding peak torque (PT), rate of torque development (RTD), fatigue resistance, and subjective perception of effort in maximal voluntary isometric contractions (MVIC) of elbow flexion. This randomized, double-blind, placebo-controlled, crossover trial with two arms enrolled 34 healthy and physically active young men, but 30 (21.10 ± 2.25 years old) completed all procedures. All volunteers were allocated into two equal arms (groups): PBMT (60 J; 1152 mW; 52 sec; and 166.75 cm) applied on biceps brachii by a flexible array of LEDs, and placebo treatment. Each arm ( = 15) investigated the time-response (5 min, 1 h, 3 h, and 6 h) of PBMT in a randomized, double-blind, and crossover manner on the PT, RTD, fatigue resistance, and subjective perception of effort. There were no significant results ( > 0.05) for all comparisons within and between groups regarding PT, RTD, fatigue resistance, and subjective perception of effort in MVIC of the elbow flexion in all time-response tested (5 min, 1 h, 3 h, and 6 h) before or after fatigue test. Only RTD did not decay significantly after fatigue test at all time-responses for PBMT group. PBMT was not effective to increase muscle performance and decrease fatigue to demonstrate the possible time-response in humans.
光生物调节疗法（PBMT）通过激光或发光二极管（LED）在过去二十年中被用于提高人体肌肉性能。PBMT 对肌肉性能的主要发现是增加扭矩和肌肉收缩次数，并在高强度运动中提高抗疲劳能力。尽管有建议的光能量需要遵循，但文献也指出 PBMT 可能存在时间反应，以增加人体的运动表现和恢复能力。
为了研究 LED 对年轻人肌肉性能的 PBMT 的可能时间反应，研究人员在最大自主等长收缩（MVIC）的肘屈肌中观察峰值扭矩（PT）、扭矩发展率（RTD）、抗疲劳能力和主观用力感知的变化。
这项随机、双盲、安慰剂对照、交叉试验有两个手臂，共招募了 34 名健康且活跃的年轻男性，但有 30 名（21.10±2.25 岁）完成了所有程序。所有志愿者均被分配到两个相等的手臂（组）：PBMT（60J；1152mW；52s；166.75cm）通过柔性 LED 阵列应用于肱二头肌，以及安慰剂治疗。每个手臂（ = 15）以随机、双盲和交叉的方式研究 PBMT 的时间反应（5min、1h、3h 和 6h）对 PT、RTD、抗疲劳能力和主观用力感知的影响。
在所有时间反应（5min、1h、3h 和 6h）下，疲劳测试前后，所有组内和组间比较在肘屈肌 MVIC 的 PT、RTD、抗疲劳能力和主观用力感知方面均无显著差异（ > 0.05）。只有 RTD 在 PBMT 组的所有时间反应中在疲劳测试后均未显著下降。
PBMT 对增加肌肉性能和减少疲劳没有效果，无法证明其在人体中的可能时间反应。
