I've been "experimenting" with saunas for a few months now, and it's like a drug. I run, lift, swim, and do yoga and all provide a unique kind of endorphin release. Running and swimming make you feel euphoric, lifting weights, relaxation. After a yoga session, somebody could rear-end me and I'd probably give them a hug. The sauna provides a feeling of all of those combined, and all you have to do is sit there.
The science: Saunas are a wonder drug. Research has shown that regular sauna use can reduce the risk of heart disease, stimulate growth hormone for muscle recovery, improve complexion, reduce toxins in the blood and even reduce stress. Recent research has shown that regular twenty-minute sessions every week reduce the risk of cardiovascular disease by 50%, and all natural causes of death by 40%. As far as stress, the extreme heat of the sauna causes the release of heat shock proteins. This heat puts the body under extreme stress which causes the release of these stress-fighting proteins. It's essentially like exposing your immune system to bacteria to strengthen it or developing antibodies to a certain disease. You put your body under extreme stress for twenty minutes, so that it takes a lot more to stress the body out in other situations.
Aside from being calm and healthy all the time, saunas can make you look better. The growth hormone stimulation can help recovery if you work out regularly, and can actually stimulate more muscle growth. More muscle growth means more fat loss since it requires more calories to maintain muscle on the body. Not to mention the benefits to skin health. The heavy sweating removes bacteria from the surface levels of the skin. Basically, you turn into a Greek god or Goddess.
The experience: I heard all of these great things and figured I had to try it. I've tried it for five minutes, ten minutes, twenty, hungover, post-workout, first thing in the morning, you name it. I've meditated in there, stretched, held conversations, and all forms of sauna use in between. My sauna time is almost always the thing I look forward to most during the week. I can't go without it anymore. You sit down and it feels interesting. You've never felt a heat like that unless you live in Arizona (I have a friend who did and he says it's very similar). It's a dry heat that you can feel instantly. For the first five minutes, it feels great. You start to notice your skin glistening, your heart beating faster, and you breathing enters the forefront of your mind. It's a workout in itself.
If you can focus on slowing your breathing, and getting used to the sweat dripping down every surface of your body, you've probably made it to the ten-minute mark. Here, you might notice a tingling in your body, at least I do. It's as if you can feel the toxins being flushed out. The skin actually responds pleasantly to touch as if rewarding you for cleansing it. Once fifteen minutes rolls around, I'll admit, it gets hard. Mental toughness takes over which is another benefit that science won't tell you about. The ability to just sit there, and push yourself to sit there, sill, in a 175-degree hotbox. If you're into pushing yourself, cool, maybe close your eyes too and focus on stillness. If you'd rather pass the time more quickly, bring a friend. Conversing while in the sauna the time goes by approximately 30% faster.
Don't bring your phone though. It will most likely overheat by the fifteen-minute mark and will be so drenched in sweat anyways that it will be rendered useless.
No matter how you go about it, the effect is the same. While the studies point to twenty minutes being the sweet spot for sauna duration, ten minutes isn't half bad. As long as you stay in until you start sweating profusely, you're good. You'll literally feel like a new person once you finally step outside and feel room temperature again. Every muscle is relaxed, every thought tamed, and all stress dissipated.
Make it a habit. Science says you won't regret it, and so do I.