Helping Muscles Recover With Red Light
Intense exercise — whether it’s a sprint at the end of a morning run, an extra set of biceps curls, or a weekend of all-day DIY home improvement projects — can temporarily damage muscle, causing soreness, inflammation, and even swelling. Phototherapy with red and near-infrared light is widely used by sports trainers, physical therapists, and athletes to aid in recovery. It may even work better than a trendy plunge in an ice bath, according to a 2019 Texas State University review.
But how does it work? Jamie Ghigiarelli, PhD, professor of Allied Health & Kinesiology at Hofstra University in Hempstead, New York, looked closely at signs of inflammation and muscle damage in 12 athletes to find out.
Study participants overtaxed their muscles with rounds of chin-ups, high-speed sprints, and repeated bench presses. Afterward, they relaxed in a full-body red-light therapy bed or in a similar bed without lights.
The results, published in 2020, showed that blood levels of creatine kinase — an enzyme that’s elevated by muscle damage — were 18% lower 1-3 days after exercising for the light-bed group than for the control group.
“Photobiomodulation seems to help with muscle recovery,” Dr. Ghigiarelli said.
Red light at wavelengths from 650 to 820 nm can enter muscle cells, where it is absorbed by mitochondria and boosts their energy production, he said. At the time of his research, some exercise science researchers and athletes thought using light therapy before an event might also increase athletic performance, but according to Dr. Ghigiarelli, that use has not panned out.
Handheld red light and near-infrared light devices for muscle recovery are widely available, but it’s important to do your homework before buying one.
“You want to choose a device with the right energy production — the right wavelength of light, the right power — to be safe and effective,” he said.
For details, he recommends consulting a 2019 paper in The Brazilian Journal of Physical Therapy called “Clinical and scientific recommendations for the use of photobiomodulation therapy in exercise performance enhancement and post-exercise recovery: Current evidence and future directions.”
The paper, from the Laboratory of Phototherapy and Innovative Technologies in Health at the Universidade Nove de Julho in Sao Paulo, Brazil, recommends that for small muscle groups like the biceps or triceps, use red-light lasers or LED devices with a wavelength of 640 nm for red light or 950 nm for infrared light, at a power of 50-200 mW per diode for single-probe device types, at a dose of 20-60 J, given 5-10 minutes after exercise.
A version of this article appeared on Medscape.com.