GoKawiilSaunas have been around since the primitive years in ancient Finland, and have always been considered to have a therapeutic effect[1]. Saunas are a hot, dry environment used to stimulate our cardiovascular system. During extreme heat exposure, our heart rate rises and our vessels dilate to increase the delivery of blood volume in order to protect the body[2].
This extra pressure on the heart is known to have long-term health benefits[3]. The heat exposure also promotes sweating and therefore the elimination of toxins, including those generated in the process of repairing small muscle tears after exercise[4]. It is for this reason that saunas are also considered great for recovery. All of this is no news, at the end of the day isn’t that what roman baths were built for? For recovery after battle[5]!
However, most studies have looked at the benefits of frequent sauna bathing and the impacts on long-term health. Motivated to understand the immediate physiological response to saunas, we looked at the same-day effects across ~59,000 daily records from 256 users.
Same-day Effects of Saunas
We used simple paired t-test evaluations to assess the immediate same-day effects of saunas.
Sauna days were associated with:
Higher activity (longer activity time and greater distance)
Higher maximum and average heart rate
That fits our intuition: many people sauna after a workout.
Sauna days also showed lower minimum heart rate compared to non‑sauna days. Importantly, this effect remains even after controlling for activity, which suggests the lower nighttime heart rate isn’t simply due to exercise. The difference between sauna and non-sauna days is on average 5% (3bpm) which is a noticeable physiological change.
... continue reading