Schematic representation of mechanisms of photobiomodulation- PBMT action on muscle oxidative stress—the oxidative stress generated during exercise or injury is linked to the migration of cells of inflammatory cells (such as neutrophils and macrophages) to the source of ROS. The increase of the reactive oxygen species triggers a redox state de-balancing. Basic biological mechanism behind the effects of PBMT: red and infrared light is absorbed by cytochrome c oxidase (IV complex of the mitochondrial respiratory chain). PBMT triggers increased ROS production, such as superoxide (O2) and hydrogen peroxide (H2O2), leading to the restoration of redox imbalance because of higher production of antioxidant enzymes. Altering the redox state in the cells induces the activation of intracellular signaling, increasing the activation of the transcription factor redox sensitive.