Red light therapy, also known as low-level laser therapy (LLLT), low-power laser therapy (LPLT), and photobiomodulation (PBM), is a therapeutic technique that involves exposing a body part to low-level wavelengths of light and helps in the repair and recovery of damaged bodily tissues. Many athletes are now turning to red light therapy before and after training to maintain peak performance and shorten recovery time. Numerous research studies have been demonstrating countless benefits of red light therapy. And with such a high volume of evidence of its efficacy, it is considered a promising intervention for many types of health conditions and injuries. Here, we are discussing some of the documented effectiveness of red light therapy on muscle performance and healing based on science.
Our bodies' muscle tissues are rich in mitochondria – the powerhouse of the cell and the muscle's source of energy – fueling up our movements for daily and recreational activities. The red and near-infrared (NIR) visible lights demonstrate a bioactive effect, or the ability of the human body to respond to specific light wavelengths with increased cellular energy production, which leads to repair of damaged tissues at the cellular level without the harmful effects of ultraviolet (UVA/UVB) light. Red light stimulates the mitochondria to produce more energy, which leads to various cellular activities and potential beneficial effects. The following are some of the effects studied in relation to red light therapy on muscles:
The increase in muscular size is associated with an increase in muscular strength, which means our muscles are able to generate a greater amount of force with lesser fatigue. Some forms of NIR before strength training have shown to improve hypertrophy and muscle size gains following an 8-week exposure and training and, in fact, demonstrated doubling in muscular size. This effect is particularly relevant to bodybuilders or to those who are aiming at gaining muscular bulk to improve their physical appearance.
As mentioned, the resulting muscular hypertrophy is associated with an increase in muscular strength. Also, the bioactive effect on muscular tissues, specifically the myosatellite cells – a muscle stem cell necessary for growth and repair–may enhance energy production, which results in an immediate increase in muscle strength and endurance.
In one theory, DOMS is caused by microtrauma to muscle fibers with an associated rapid influx of calcium into the muscle cells, leading to damage, inflammation, and soreness. Red light therapy induces increased ATP (energy) production for calcium reabsorption out from the muscle cells, reducing the severity of DOMS and resulting in faster recovery.
Inflammation is a typical feature of muscle damage. Red light therapy may help in reducing the severity of inflammation by increasing the amount of carbon dioxide (CO2), inhibiting the inflammation process. This allows damage repair while preventing the formation of scar tissue.