#080 How Heat Therapy Improves Slow Wave Sleep

Two 20-minute sauna sessions at 80 degrees Celsius with 30 minutes of cooling period in between can double growth hormone levels basically from their baseline ... Two 15-minute sauna sessions at about 100 degrees Celsius, dry heat, separated by a 30-minute cooling period can cause a five-fold increase in growth hormone levels.

Prolactin, in one study, men that use the sauna—they were in an 80 degrees Celsius sauna until they felt exhausted—they had a ten-fold increase in prolactin levels. In another study, women who did a 20-minute dry sauna twice a week had a 510% increase in prolactin levels after each sauna session.

An example of a sauna protocol could be 20 minutes in a at least 176 ºF sauna, at least 1-2 hours before bed allowing the body enough time to cool down before sleep.

Likewise, taking a warm bath before sleep increased the proportion of slow-wave sleep—the deep restorative phase of our sleep cycle that is important for staving off neurodegenerative diseases like Alzheimer's disease.

Passive body heating—in other words, raising your body temperature without exerting yourself through physical activity—has been shown to facilitate sleep onset.

It is important to know that exercising too close to bedtime might have the opposite effect due to the acute effects of the increased alertness and the increases in core body temperature without being able to cool down before going to bed. So, it's generally, I think, recommended to engage in exercise earlier in the day, or just not right before bedtime.

Sauna use is probably one of the most powerful stimuli that increases both growth hormone and prolactin.

As ATP is being used or utilized during exercise, it breaks down into adenosine; and adenosine is a neuromodulator that plays a role in promoting sleep.