You know that old quote that says any sufficiently advanced technology is indistinguishable from magic? That’s how it feels to look through the scientific literature for light therapy, also called photobiomodulation.
Light therapy sounds like a crazy, unproven, pseudoscientific baloney: shine different colors of light on your body and achieve hitherto unreached health and fitness goals.
The thing is that there’s a ton of evidence to back it up, way more than you’d expect. A lot of people speak of light therapy as a means for remedying seasonal affective disorder (SAD), a type of depression related to changes in seasons, but there are scores of studies that have shown it can have a positive impact on strength gains, hypertrophy, muscle soreness, and injury recovery. It’s even gaining traction among Olympic athletes.
Remember how sunlight stimulates the production of Vitamin D? It’s starting to look like the body interprets many other kinds of light as signals to stimulate or suppress a huge amount of biological processes.
It sounds far-fetched. The science says otherwise.
What Are the Benefits of Light Therapy for Athletes?
The idea is that different wavelengths and light strengths have different effects on the body. Blue light, for instance, is often used for skin health, as there’s evidence it may treat pre-cancerous skin spots and even acne. Green light is often used for sleep and for pain management. (These types of light have many other uses too, these are just examples.)
Typically, it’s red and near-infrared (NIR) light that is of the greatest interest for athletes.
“Red and NIR diodes have strong evidence as recovery tools and as tools to help to build strength and muscle,” says Dr. Lew Lim, founder and CEO of therapeutic photobiomodulation technology company Vielight, Inc. “The way it works is it helps to activate what you call the gene that leads to muscle recovery and tissue repair. Exercise creates mini tears in the muscle and your body rebuilds the tissues and that’s where you gain strength. When you deliver red light to these areas, you’re helping your muscles rebuild in a quicker way.”
The idea is that red and NIR light therapy stimulate our mitochondria, which generate cellular energy, but Lim notes that mitochondria also activate genes that give signals to repair your muscles.
Light therapy also releases nitric oxide back into the body, which could lead to improved circulation, plus there’s also evidence it can improve the production of growth hormone and the expression of heat shock proteins, which help our cells withstand stress. Shone directly onto the testes, it may even increase testosterone.
“When you see the increase in nitric oxide, the improvement in growth hormone, the recovery, the increase in heat shock proteins and cellular resilience from that, the improvement in heart rate variability, the attenuation in strength loss and muscle loss, the variety of benefits is so great that I really feel (light therapy) is of benefit to the strength athlete,” says Ben Greenfield, a human performance consultant based in Spokane. “And then because of the blood building and cardiovascular benefits it’s also of benefit to the endurance athlete, too.”
How Can I Use Light Therapy to Improve My Strength?
A 2016 review of forty-six randomized controlled trials and case-control studies concluded that laser probes, clusters of laser diodes, LED clusters, mixed clusters, and flexible LED arrays “can increase muscle mass gained after training, and decrease inflammation and oxidative stress.”
Basically, there are a lot of different ways to incorporate light therapy. There are two that are most popular for the purpose of sports performance and the first is simply installing them around your home like regular lamps.
“I’ve installed near and far infrared panels at a wavelength of about 600-700 nanometers in my office along with a little red light, called the Ruby Lux bulb, in my office to allow me to work with red light in my office and not disrupt my circadian rhythms when I’m working at night,” says Greenfield. “In addition to that, I use my biological LED lighting in my house by a company called Lighting Science — red bulbs in the bedroom and blue bulbs in areas of wakefulness, like the gym and the office.”
Then there are techniques that are more direct.
A 2007 study exposed four bodybuilders to lasers intravenously by feeding the light through a tube that was inserted under the skin. (The idea is that when you shine red light into the circulating blood itself for about twenty minutes, you’ll have refreshed enough of your body’s circulatory system to make a difference in your energy production.) Exposed to ten sessions of twenty minutes each over three weeks, the athletes were tested in their max bench, deadlift, and squat.
After the therapy was over, each of the lifts were shown to have increased by about ten kilograms. They then slowly decreased to baseline after about sixteen weeks, which is about the average lifespan of a red blood cell. (Meaning all the cells that had been hit by the first round of light therapy had died and been replaced after those sixteen weeks.) The subjects also significantly increased their endurance in swimming and jumping rope during the same time period.
It’s a small sample size and the study’s imperfect, but the findings are consistent with other studies that have shown increased exercise capacity. One 2016 study of identical twins even found that after twelve weeks of training legs, the leg press of the twin on light therapy increased by almost eighty percent more than the twin who had a placebo treatment. (It went a long way in reducing muscle soreness, too.)
For those of us who don’t like the idea of opening up a vein three times a week, there are other options. That study with the leg pressing twins, for instance, used a flexible light-emitting diode array, which is basically a bunch of light bulbs wrapped around the quad.
A more common solution for the average joe is intranasal light therapy — yep, that’s the light that clips onto the nose.
“Because there are a lot of capillaries and the membrane is very thin, it doesn’t require a lot of power to deliver the light into the body,” says Lim.
If you were to buy an intranasal device, how much should you use it? Your sessions should last a good twenty to twenty-five minutes. Lim likes to have dedicated sessions every day and Greenfield prefers ever other day, but as you can see from the studies above, a routine of three weekly sessions appears to have pretty significant effects as well.
Studies show that using lightwaves of between 600 and 1200 nanometers is the sweet spot. (The leg day twins were using 850 nanometers and the light-injecting bodybuilders were on 630 nanometers, FYI.)
This hasn’t been an exhaustive look at photobiomodulation. We’ve barely touched on the uses of blue light and green light, or the ways people are using the practice to improve sleep, mood, and other areas of your health.
But there’s enough evidence to show that light therapy isn’t some fringe pseudoscience. We’ve long known that sunlight improves our immunity, mood, and hormones, and now we know that our body also responds positively to other areas of the light spectrum.
Light therapy isn’t particularly cheap. An intranasal device from Vielight with 633-nanometer wavelength light is about $300, and the cost increases as the nanometers do. Colored light bulbs like Ruby Lux are cheaper (under $50) but they can be hotter and arguably more intrusive as they bathe the entire room in red light.
But if the numbers above have impressed you, light therapy may be a worthy investment. We’ll be keeping our eye out as more research comes out on the subject.
Featured image via @terrance.lindsay on Instagram.