Yesterday, on Tim Ferriss' very popular blog, there is a post discussing the science of sauna exposure and improved health and performance. Among the highlights of that post:
One study demonstrated that aand...
two 15-minute sauna sessions at 100°C (212°F) dry heat separated by a 30-minute cooling period resulted in a five-fold increase in growth hormone.Fifteen minutes in a 100°C sauna is pretty rough, but the point is that the exposure has to be difficult or prolonged enough to be uncomfortable. It's supposed to be difficult. And so it goes with exercise, fasting, or any other kind of physical stressor. Suffer, endure, recover.
What I found most interesting was that there is actually a "discomfort chemical" produced in the body, dynorphin:
Beta-endorphins are endogenous (natural) opioids that are a part of the body’s natural painkiller system, known as the mu opioid system, which block pain messages from spreading from the body to the brain in a process called antinociception. What is lesser known is that the body also produces a peptide known as dynorphin (a “kappa opioid”), which is generally responsible for the sensation of dysphoria. The discomfort experienced during intense exercise, exposure to extreme heat (such as in a sauna), or eating spicy food (capsaicin) is due to the release of dynorphin. The release of dynorphin causes an upregulation and sensitization of mu opioid receptors, which interact with beta-endorphin.46 This process is what underlies the “runner’s high” and is directly precipitated by the discomfort of physical exercise.Anyway, it's certainly not a scientific be-all and end-all on the matter, but it's an interesting read and potentially one more point in favour of acute discomfort.