Sauna Training

What is sauna training?

The phrase covers two related habits that often get lumped together. The first is the fight-week weight cut, where a fighter sits in a hot room to sweat off water and hit a lower number on the scale. The second is heat conditioning, where repeated sessions during a training camp push the body to adapt in ways that carry over to cardio and recovery.

Both rely on the same trigger: heat that the body has to fight against. When core temperature climbs, the heart works harder and the sweat glands open. Do it once before a weigh-in, and it is a weight-cutting tool. Do it three times a week for a month, and it becomes a conditioning stimulus.

Fighters run into sauna training in two places. One is the final days before a bout, when every pound matters. The other is the quieter part of camp, folded into recovery days alongside cold plunges and sleep. Knowing which version someone means is usually the difference between a health risk and a health habit.

How sauna training works

Heat is a stressor, and the body treats it like one. Step into a sauna and core temperature rises, blood vessels near the skin widen, heart rate climbs, and sweat starts pouring to shed the load. A traditional sauna runs hot, roughly 80 to 100 degrees Celsius, while an infrared sauna is cooler, around 40 to 60 degrees Celsius, and heats the body more directly, according to strength coach James de Lacey of Sweet Science of Fighting.

For a weight cut, the point is simply the sweat. A fighter can drop several pounds of water in a session, then put most of it back on after the weigh-in through food and fluids. That loss is real on the scale and almost entirely temporary.

The conditioning side works differently. Repeated heat exposure nudges the body to hold more blood plasma, which helps the heart pump more efficiently. In one study by Stanley and colleagues, athletes who used the sauna after endurance work saw plasma volume rise by about 18 percent and resting heart rate drop by roughly 10 percent. Research by Scoon and colleagues found competitive runners improved their time to exhaustion by 32 percent after twelve post-exercise sauna sessions across three weeks. Those are the adaptations a fighter is chasing when heat becomes part of camp rather than a weight-cut tactic.

Cutting weight vs. heat adaptation

Most confusion around sauna training comes from treating its two purposes as one. They share a room and a temperature, but almost nothing else. The table below lays out the split.

	Cutting weight	Heat adaptation
Goal	Drop water weight to make a lower division	Improve cardio and recovery over time
When	The final days and hours before the weigh-in	Throughout a training camp, often on recovery days
What changes	The body sheds water through sweat	The body holds more blood plasma and handles heat better
How long it lasts	Temporary, reversed by rehydration	Lasting while the habit continues
Main risk	Dehydration, dangerous when pushed hard	Low, when hydration is managed

A fighter sweating out four pounds the night before weigh-ins and a fighter sitting in the sauna after a Tuesday conditioning session are doing two different things with the same hot room.

Types of sauna training

The heat can come from a few sources, and each has its own feel and practical trade-offs.

Type	Temperature	What to know
Traditional sauna	80–100°C	Heats the air and warms the body from the outside; turns humid when water hits the rocks
Infrared sauna	40–60°C	Heats the body directly; feels cooler but reaches deeper, so it is easier to tolerate longer
Sauna suit	Trapped body heat	A waterproof suit worn during exercise; common in the final weight cut
Hot bath	Hot water	Immersion that raises core temperature fast; a stand-in when no sauna is available

Sauna suits deserve a note of their own. They work by trapping sweat against the skin so it cannot evaporate, which raises core and skin temperature and adds physiological stress even during light work, as Sweet Science of Fighting explains. That makes them popular for cutting weight, though they carry the same dehydration cautions as any hard cut.

Common misconceptions and risks

A few myths cling to sauna training. One is that sweating detoxes the body. Sweat is mostly water and salt, and the organs that clear toxins are the liver and kidneys, not the pores. Another is that the sauna builds muscle by spiking growth hormone. De Lacey points out that the growth hormone rise from a sauna is smaller than the rise from lifting weights, and even injected growth hormone has failed to increase muscle size or strength in controlled trials, so the muscle-building claim does not hold up.

The risk lives in the weight-cutting version. Rapid dehydration strains the heart and kidneys, and aggressive cuts have caused serious harm to fighters, including hospitalizations and deaths in combat sports. So the weight-cut use is handled as a supervised procedure rather than a casual habit. Done at sensible temperatures with proper hydration, the conditioning use is far safer.

Frequently Asked Questions

Do UFC fighters use saunas?

Yes. Many UFC and other MMA fighters use saunas both to cut water weight in the final days before weigh-ins and as a recovery and conditioning tool during camp.

Is sauna training the same as cutting weight?

No. Cutting weight is one use of the sauna, focused on sweating off water before a weigh-in. Sauna training also covers heat conditioning, which aims at cardio and recovery and produces lasting adaptations.

How long do fighters stay in the sauna?

It varies by purpose. Conditioning sessions in the research often run around 30 minutes, while weight-cut sessions are usually broken into shorter rounds with breaks until the fighter hits the target weight.

Is sauna better before or after training?

For conditioning gains, research points to using the sauna after a session. Using it before intense work can add stress the body does not need.

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Sources

1. de Lacey, James. “Is The Sauna Good For MMA?” Sweet Science of Fighting.
   https://sweetscienceoffighting.com/mma/sauna-for-mma
2. Scoon, G. S., et al. “Effect of post-exercise sauna bathing on the endurance performance of competitive male runners.” Journal of Science and Medicine in Sport, 2007.
   https://www.researchgate.net/publication/6909623_Effect_of_post-exercise_sauna_bathing_on_the_endurance_performance_of_competitive_male_runners
3. Stanley, J., et al. “Effect of sauna-based heat acclimation on plasma volume and heart rate variability.” European Journal of Applied Physiology, 2015.
   https://link.springer.com/article/10.1007/s00421-014-3060-1
4. Mero, A., et al. “Effects of far-infrared sauna bathing on recovery from strength and endurance training sessions in men.” Springerplus, 2015.
   https://link.springer.com/article/10.1186/s40064-015-1093-5
5. Klerck, Ray. “Why Now Is The Time Every Fighter Needs To Sauna.” Fighters Only, October 2025.
   https://fightersonly.com/article/ext/92040/Issue+222/1

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