Heat is the other hormetic lever. Finnish cohort data is why Rhonda Patrick would not shut up about sauna: frequent use lining up with better cardiovascular numbers in those datasets. You sit in 80–100°C, you sweat, heart rate looks like easy cardio, heat shock proteins do their thing. It is not a substitute for Zone 2. It is a strong extra if you will actually show up.
How to use it
Traditional or infrared. Traditional runs hotter. Infrared is easier in an apartment (blanket, portable steam). Start 10–15 minutes, build toward 15–20, two to four times a week if you tolerate it. Hydrate. Get out if you feel faint, nauseous, or confused. Alcohol plus sauna is a classic way to meet a tile floor.
Contrast with cold is optional theater. Heat alone still counts. This feeds longevity, cardio, and sleep if you do not go so late that you are cooked at bedtime.
FAQ
Infrared or Finnish?
Finnish data is on hot air saunas. Infrared is more convenient. Use the one you will sit in.
Can I sauna every day?
Some people do. Start at 2–3 sessions. More is not automatically more longevity.
Is it cardio?
Heart rate rises. It is not a replacement for walking hills or a bike you slightly hate.
Skip or get clearance with unstable heart disease, pregnancy, or if you have ever fainted in heat.




