Sauna Will Extend Your Health-span

Repeated exposure to sauna appears to induce a physiologic response in our bodies that is similar to moderate to vigorously intense cardiovascular exercise. A large ongoing observational study of 2,300 men in Finland has demonstrated some amazing cardiovascular health benefits with sauna use. Men that engaged in sauna use 2-3 times per week where shown to have a 22% decrease in risk of sudden cardiac death and those that used the sauna 4 or more times per week were shown to be 63% less likely to experience sudden cardiac death. The same study showed that frequent sauna users were 40 percent less likely to die from all causes of premature death with even when the population studied was controlled for age, activity level and other lifestyle factors.

The benefits from sauna that have such a dramatic effective on a person’s lifespan will also benefit the aging athlete’s desire to keep getting after it. The basket of positive physiologic reactions to regular sauna are mediated by our body’s cardiovascular and hormonal responses to heat exposure. Frequent use of sauna will help the aging athlete improve their cardiovascular endurance and maintain their muscle mass, while also accelerating the injured athlete’s return to sport.

Sauna use improves and helps maintain cardiovascular endurance. One small study looked at the effects of repeated sauna use on athletic performance in male distance runners. The findings showed that one post-workout sauna session twice a week for three weeks increased the time that it took for the study participants to run until exhaustion by 32 percent compared to their baseline.

A 32% improvement in endurance over 3 weeks is remarkable and probably due to our body’s acute response to heat exposure. Repeated exposure to sauna causes an increase in the number of red blood cells and blood plasma volume which has a downstream effect of decreasing our heart rate and body temperature at a given workload.

Our muscle fibers that specialize in endurance require a constant supply of oxygen to function. An increase in the number of red blood cells improves our body’s ability to carry oxygen to those needy muscles. Furthermore, an increase in the number of red blood cells allows us to offload more carbon dioxide, a gas that limits the oxygen carrying capacity of our blood. Another rate limiting step in our capacity to exercise is body temperature, as your body temperature increases your potential endurance decreases. An increase in plasma volume improves our ability to sweat, and thus off-load heat, decreasing our heart rate for a given workload.

Sauna use can also have an important role in adding and maintaining muscle mass due to our hormonal response to heat. Two studies looking at the acute effects of sauna use on growth hormone show a 2-5 fold increase in this hormone, with the larger increase coming with a hotter sauna. Another study looked at growth hormone and daily sauna use for 7 days straight. This study found a 16 fold increase in circulating growth hormone. The growth hormone effect from sauna use is particularly relevant for the aging athlete. Our bodies are constantly breaking down muscle tissue and rebuilding it. As we age, we cannot build muscle tissue fast enough to keep up with its degradation. For the aging athlete, regular sauna use will help balance out our protein degradation with our protein synthesis, slowly down age related muscle atrophy.

The injured athlete’s hormonal and anti-inflammatory response to the sauna will help speed up their return to sport. After an injury, joints and/or muscles can be red, hot and swollen. This reaction is our body’s immune system going to work on repairing the injured tissue. Sauna use at this point can exacerbate the swelling and do more harm than good. Regular sauna use after the swelling, and redness subsides, can slow down the muscle atrophy that occurs from immobilization and/or disuse. The more muscle we can retain while injured, the faster we will heal when we start therapeutic exercises. For chronic inflammatory conditions (arthritis, etc.), regular sauna use can reduce overall systemic inflammation, decreasing pain associated with movement.

So the question is how hot, how long and how often should we a sauna? There are no standardized protocols for sauna, but we can glean some good guidelines from studies. Generally speaking a sauna’s positive effect is dose dependent. This means that the temperature, duration and frequency have a statistically significant effect on our cardiovascular and hormonal response. To optimize the positive benefits you should look to do 3-4 sessions a week, lasting 20 minutes, at a temperature of 170 or more. That being said, shorter sessions and lower temperatures have also been shown to elicit the same positive, albeit a more muted cardiovascular and hormonal response. If twenty minutes in a sauna is challenging, you can accrue the same benefits while breaking up the 20 minutes into smaller increments with a cooling period in between.

While there are incredible benefits to sauna bathing, some people should use caution. Sauna use has been shown to decrease sperm count in males, but this appears to reverse itself once regular sauna use is discontinued. While sauna does not appear to be dangerous during pregnancy, for the mother or the child, it is best to consult your doctor. Sauna use by children over 2 years old also appears to be benign. However, children cannot thermo-regulate as well as adults and thus should be supervised and their time in the sauna should be much less than that of adults. If there is any doubt as to whether you can tolerate a sauna or not, please consult your doctor.

To conclude, sauna has amazing benefits for your cardiovascular and musculoskeletal systems. Additionally, because the sauna is a passive modality, it can extend the benefits of your cardiovascular and strength training workouts without additional stress on your joints and surrounding connective tissue. Furthermore, those that are sedentary due to injury or lifestyle can also accrue the benefits of sauna. Lastly, if you are injured, consider adding regular sauna use to your rehabilitation protocol to enhance and accelerate your return to sport.