Treatment With Near Infrared Light Prevents Muscular Fatigue After Intense Exercise in Mouse Models — MHSRS 2023

Cheema N, Nazarian A, Pham L, Ghag N, Fuchs C, Tam J, Anderson R

Abstract accepted for a poster session at the 2023 Military Health System Research Symposium

Fatigue is defined by the reduction of a muscle’s strength and performance during exercise, and it is affected by different parts of the motor pathway controlling muscle contractions. Fatigue can occur in the central nervous system and affects neuronal signaling to the muscle whereas peripheral fatigue affects the site of neuromuscular junctions present on the muscle. Fatigue limits performance and unless allowed to recover, continuous activity will result in muscle dysfunction and musculoskeletal injuries that are commonly observed in military personnel. Light therapy has been shown to have several beneficial physiologic effects in a wide range of tissues. The musculoskeletal system can be irradiated with wavelengths in red and near infrared (NIR) regions which penetrate deep into the body. Application of NIR light is a noninvasive procedure and there is minimal heat generated by the light emitting diodes (LEDs), making it an appealing therapeutic strategy for muscle damage. Recent studies are suggesting that photobiomodulation therapy (PBMT) can reduce pain, inflammation and enhance physical performance. However, the mechanism(s) of cellular responses by PBM in muscle is not clearly understood. There is no standardization in parameters for PBMT, with researchers and clinicians using a wide range of wavelengths, fluences, treatment duration/frequency, etc. in PBM applications. Therefore, the goal of this study is to improve our understanding of the mechanism(s) of action of PBM effects on the musculoskeletal system, ultimately to inform the choice of clinical treatment parameters. We investigate two wavelengths in NIR light, 980 nm and 810 nm, and their effect on fatigue induced in intense exercise in cells and mice.