Have you ever felt like a "100-year-old" after a week in bed with the flu? Well, that's not far from the truth. Muscles disappear quickly when we don't use them, but fortunately, infrared sauna can significantly slow down muscle wasting.
As we age, we naturally lose muscle mass, but it can also be due to illness or injury. While exercise can help combat muscle loss, some medical conditions or physical limitations can make exercise difficult or impossible.
In muscle wasting (muscle atrophy), muscle tissue shrinks because muscle cells become smaller and muscles weaken. We will all experience muscle loss over time, but how much and how quickly it happens depends on how well we take care of our bodies and health.
Inactivity or sedentary behavior affects many processes in the body, ranging from the obvious, such as reduced strength and movement, but we also experience poorer mood, metabolism, circulation, fitness, and quality of life.
Heat treatment prevents muscle wasting
In a podcast published on Found my fitness, the renowned doctor and researcher, Rhonda Patrick, explains how sauna use and heat treatment help preserve muscle strength. Studies show that heat therapy can have an "anti-atrophy effect."
– Researchers found that local heat treatment on unused muscles prevented muscle wasting by up to 40% compared to the control group. In other words, muscle loss occurs regardless of inactivity, but heat treatment can slow down the loss.– This is significant, and consistent with previous animal studies. I am glad to see the same results in humans.
How much and how quickly we lose muscle strength and muscle mass when we transition from an active to an inactive life has surprised even researchers.
In a Danish study, men of different ages had one foot in a cast for 14 days. While the young men lost one-third of their muscle strength and 485 grams of muscle mass, older men lost about one-quarter of their muscle strength and 250 grams of muscle mass.
This means that the inactive muscles of a 20-year-old aged equivalent to 40 to 50 years. In two weeks, the muscles in the foot "belonged" to a man in his 60s.
If you are trained, you lose more muscle mass than if you are untrained. However, if you are older, the loss is considered more critical as it has a greater negative impact on health.
All participants in the study also experienced reduced fitness.
Afterwards, the participants were to cycle 3-4 times a week for six weeks. This proved not to be enough to regain their original muscle strength. To regain muscle strength, it must be combined with strength training. It takes three times as long to get back to the starting point.
Three weeks in bed is like 30 years of aging
Another study showed that three weeks in bed had a greater negative effect on physical fitness than 30 years of aging. In three weeks, participants went from being, for example, 40 years old to 70 years old in terms of muscle.
There are, of course, individual differences here, but these are very interesting observations.
If we use men with casts as an example. If both legs were inactive and one was cast while the other received local heat treatment, the foot with heat treatment would have lost 291 grams of muscle mass instead of 485 grams like the leg without heat therapy.
Sauna provides a robust increase in heat shock proteins
In the podcast, Patrick explains that the mechanisms that prevent greater loss of strength and muscle mass are mainly due to the robust increase in heat shock proteins and growth hormones that occur with induced heat stress, such as in a sauna.
She refers, among other things, to a study where heat therapy slowed down muscle loss in the hind limbs of rodents by up to 32%. The rodents that received heat treatment lost significantly less muscle weight than the control group.
A small study on healthy young individuals found that 1 hour of heat treatment led to increased activity in markers that help maintain muscle mass and protect against muscle wasting.
In another study, it was discovered that daily heat treatments applied locally to inactive muscles for 10 days attenuated skeletal muscle wasting by 37% compared to the control group. Once again, due to increased activity in heat shock proteins, among others.
The findings suggest that heat stress can serve as an effective therapeutic strategy to slow down the reduction in muscle mass that accompanies periods of inactivity.
– Heat shock proteins are one of the most protective, adaptive responses to induced heat stress. Many things stimulate heat shock proteins, but heat stress significantly increases their levels, and they can remain activated for 48 hours after a sauna session, Rhonda Patricks further explains in the podcast.
Never too late
The reason muscles quickly break down during inactivity is primarily that the body adapts to the activity level. It is the muscles that are used most in everyday life that disappear first – and it happens particularly quickly during the first inactive week.
Previously, researchers believed that the ability to build muscles had an expiration date after a certain age. This was disproved in a study in the 90s when a group of 80 to 100-year-olds started strength training and experienced a strength increase of over 100%.
It's never too late to start exercising or integrate infrared sauna as part of your fitness routine or wellness regimen.
Studies show countless health benefits associated with sauna use. This is mainly due to the mechanisms that occur in the body induced by heat stress. Heat stress triggers many of the same processes that occur in the body when we exercise.
Infrared sauna can be a powerful tool against muscle wasting. It is for everyone, but especially for those who cannot exercise regularly. Sauna can be used by athletes who are injured, chronically ill, or to preserve as much muscle mass as possible and general good health.
NB: Do not use the sauna if you have a fever. Check contraindications under frequently asked questions if applicable. This post is intended as a sharing of interesting observations, not medical advice. If you have conditions that make you unsure whether sauna is for you, consult your doctor.
Text: Trine Dahlman
