Benefits of Saunas
The Go Ask Alice website, a health education website from Columbia University, states that sweating in a sauna opens your pores and cleanses the surface of the skin, provides relaxation, and lowers your pulse rate and blood pressure as your blood vessels dilate. MayoClinic.com says there is some evidence that infrared saunas -- which use light to heat your body directly instead of a traditional sauna, which warms the air that in turn warms your body -- might help people with high blood pressure, heart failure and arthritis. However, larger and better-designed studies are necessary to confirm those initial findings.
Lack of Hydration
If you don't rehydrate after a postworkout sauna, it can be unhealthy and perhaps even dangerous. According to Military.com, the consequences of excessive sweating from a sauna can include kidney damage due to a loss of electrolytes and possibly even heatstroke, which can be fatal. To hydrate properly, drink sufficient water before, during and after your workout, as well as during and after your stint in the sauna. A sports drink can replace lost electrolytes.
If you have certain health conditions, you'll want to avoid using a sauna after you exercise or at any other time. People with certain types of heart disease, such as abnormal heart rhythms or valve disease, should stay out of the heat, according to Harvard Health Publications. So should people with extremely high or low blood pressure, epilepsy, or anyone who is using antibiotics, stimulants, tranquilizers or alcohol, states Go Ask Alice. Pregnant women should avoid the sauna as well.
The notion that saunas help you lose weight is a myth. Unfortunately, as Military.com explains, a postworkout sauna doesn't result in anything more than temporary weight loss, since you're merely sweating out water weight that you'll put right back on when you hydrate. In fact, Harvard Health Publications says there is little evidence, as of 2013, that saunas provide significant health benefits "above and beyond relaxation and a feeling of well-being."