Although I do not consider heat and cold exposure a core tenet of longevity, they are a powerful tool to maximize the benefits of your training.
Here are two heat exposure protocols from Dr. Rhonda Patrick (@foundmyfitness):
For improved endurance: A 30-minute post-workout sauna session twice per week for 3 weeks increased the time it took for study participants to run until exhaustion by 32% compared to baseline.
For increased growth hormone (GH): Two 20-minute sauna sessions at 80⁰C (176⁰F) separated by a 30-minute cooling period elevated GH levels two-fold over baseline. Alternatively, two 15-minute dry-heat sessions at 100⁰C (212⁰F) separated by a 30-minute cooling period resulted in a five-fold increase in GH. In both cases, the GH spikes persisted for a couple of hours post-sauna.
If you don’t have access to a sauna (like me), hot baths are an effective alternative to increasing GH over baseline in addition to causing a large release of prolactin which helps to heal wounds.
Tim Ferriss stays in a hot bath or sauna for around 20 minutes. This is generally long enough to significantly increase his heart rate and make him feel dysphoric (but NOT dizzy or lightheaded) and want to get out (this coincides with dynorphin release). Once you get out, cool off by drinking ice water or with an ice bath or cool shower.
He repeats this cycle of heating and cooling 2-4 times.
Note on Cold Exposure Timing
Studies have shown that cold exposure (entering an ice bath or cold plunge, but probably not a cold shower since it is not cold enough) can interfere with progress from muscular and cardiovascular training.
Try to perform cold exposure on a rest day or if on a training day as many hours apart from your training session as possible.
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