Intermittent post-exercise sauna use increases markers of performance
The science is clear: intermittent passive heat training (i.e. sauna use), in conjunction with an active training schedule, can result in significant improvement in performance – especially for sub-elite athletes. While passive heat training alone is not as effective as active heat training, when paired together the two can be more effective at inducing heat adaptations and performance improvements than active heat training alone.
Male Runner Study
A study published in the Journal of Science and Medicine in Sport examined how sauna bathing after exercise affects endurance performance in male distance runners. Over a three-week period, participants who used the sauna post-training saw significant improvements in their running performance, including increased time to exhaustion and enhanced blood volume, suggesting a beneficial adaptation for endurance athletes.
The study involved six male distance runners who completed their normal training and added sauna sessions (~30 minutes at 87°C) following each workout, 4 times per week for 3 weeks. Researchers measured plasma volume, red cell volume, and performance via a treadmill run to exhaustion at the participant’s VO₂max pace before and after the intervention.
After 3 weeks of post-exercise sauna bathing, participants demonstrated:
• Increased time to exhaustion during treadmill testing (+32%)
• Increased plasma volume (+7.1%)
• Increased total blood volume (+5.6%)
The findings suggest that regular post-exercise sauna use can improve thermoregulatory and cardiovascular function, ultimately enhancing endurance performance in distance runners.
Female Runner Study
A study published in the European Journal of Applied Physiology explored the effects of intermittent post-exercise sauna bathing on trained middle-distance runners. Over a three-week period, participants who incorporated sauna sessions after their workouts experienced notable improvements in heat tolerance and exercise performance. Specifically, these athletes exhibited reduced core and skin temperatures, lower heart rates during heat tolerance tests, and enhanced aerobic capacity compared to those who did not use sauna bathing.
The study examined twenty middle-distance runners (13 female, 20+-2 years, VO2max 56.1 ± 8.7 ml kg−1 min−1 ) in which half of them followed normal training (CON), and the other added sauna bathing (SAUNA; ~28 min at 101–108 °C, 3x/week) after training. Heat tolerance test + lactate and Vo2max test before and after the 3 weeks (30-min, 9 km h−1/2% gradient, 40 °C/40%RH)
Six SAUNA participants continued the intervention for 7 weeks and completed an additional HTT.
After 3 weeks, compared to CON, the SAUNA group showed:
- Lower peak rectal temperature (−0.2 °C)
- Lower skin temperature (−0.8 °C)
- Lower heart rate during heat tolerance test (−11 bpm)
- Improved VO₂max (+0.27 L/min)
- Higher lactate threshold speed (+0.6 km/h)
After 7 weeks, only peak rectal temperature decreased further (−0.1 °C), with no additional significant changes in other variables.
How to Incorporate Sauna Sessions into Training
If you are looking for detailed guidance on how to incorporate sauna sessions into your training schedule, CORE Coach Erik Åkesson has written an article on the subject.
He explains, "How I schedule heat training blocks differs a bit from athlete to athlete, but I like to work with 10–14 days of heat training every day, followed by maintenance heat 2–3 times a week for some weeks before repeating heat again. Between active and passive sessions, that should keep your CORE Heat Adaptation Score between 90–100%."
Track it in the CORE App
The new passive Heat Training Load feature in the CORE App allows athletes to manually input the details of their passive heat training sessions and see how they impact their daily overall Heat Training Load and cumulative Heat Adaptation Score.