This clinical study regarding the concept of Photobiomodulation (PBM), which involves the use of red or near-infrared (NIR) light to stimulate, heal, and regenerate damaged tissues. Specifically, it examines the impact of PBM on human muscle tissue in the context of sports performance, both in clinical trials with volunteers and in athletes. The review categorizes the effects of PBM into those that positively affect muscle performance and recovery, and those that do not have any effect.
The methodology included searching MEDLINE for randomized controlled trials and case-control studies involving both healthy trained and untrained participants, as well as elite athletes, up until the year 2016. The performance metrics considered in these studies included fatigue, number of repetitions, torque, hypertrophy, and measures of muscle damage and recovery such as creatine kinase levels and delayed onset muscle soreness.
From a total of 533 studies retrieved, 46 were included in the review, encompassing 1045 participants. The studies varied in their use of PBM devices, including single laser probes, clusters of laser diodes, LED clusters, mixed clusters (combining lasers and LEDs), and flexible LED arrays. The wavelengths of light used included both red and NIR, as well as mixtures of red and NIR light.
The review found that PBM can increase muscle mass gained after training, and decrease inflammation and oxidative stress in muscle biopsies. Given these findings, the review raises an important question regarding the legality and ethical considerations of using PBM in athletic competitions, suggesting that international regulatory authorities should decide whether PBM should be allowed.
https://pubmed.ncbi.nlm.nih.gov/36782179/