Deliberate heat.
Backed by science.

As your core temperature climbs in the sauna, the cardiovascular system responds in a way researchers compare to moderate aerobic exercise: heart rate rises, the heart works a little harder, and blood vessels open up across the body. A 2025 review in Frontiers in Cardiovascular Medicine reported that the responses to sauna bathing closely resemble those of moderate to vigorous aerobic exercise (Sastriques-Dunlop et al., 2025). That's part of why sauna is so interesting for people who can't train hard. At the cellular level, heat also prompts the body to produce heat shock proteins, which researchers associate with cellular repair and resilience. We're describing what the research has found, not making a promise about your health.

The two produce overlapping but slightly different effects. A 2025 study in the American Journal of Physiology compared them directly and found traditional steam produces a stronger cardiovascular and thermoregulatory response, including a greater rise in core temperature (Akerman et al., 2025). Infrared runs cooler but has been shown to penetrate a few centimetres into tissue (Mero et al., 2015), which is why people often pick it for recovery and easing muscular tension at a more tolerable temperature. The long-term Finnish cohort data is based on traditional steam. Short version: infrared for deep, comfortable recovery; steam for the stronger response and the classic experience.

Sweat is mostly water and electrolytes with traces of other compounds, and sauna brings on a lot of it. The heat also opens the pores, and regular sauna use has been associated with better skin hydration and texture. Worth being straight here: your kidneys and liver are your actual detox organs. Sauna supports how you feel and how your skin looks, but the popular idea that you're sweating out heavy metals isn't well supported, so we won't pretend otherwise.

Heat stress has been shown to prompt a release of growth hormone, which plays a role in muscle repair and recovery, though the size of the effect varies a lot with temperature, length and how often you go. Research on far-infrared specifically reported meaningful growth hormone increases alongside that deeper tissue penetration (Mero et al., 2015). For people who train, this is part of why a regular sauna habit sits so well alongside recovery, on top of the simple fact that heat loosens tight muscles and helps you relax.

The humid heat of a steam sauna opens the airways and a lot of people find it clearing and pleasant to breathe in. Research has associated regular sauna use with various respiratory and inflammatory measures, and it's an active area of study. As always, we're pointing to what the research explores rather than claiming sauna treats any condition. If you have a respiratory or other health condition, have a chat with your doctor before you start.