After a hard workout, the sauna, steam room, or hot tub can sound pretty appealing. Heat exposure may help you relax, and some forms of passive heat therapy have promising evidence for cardiovascular health, heat acclimation, and certain recovery outcomes.
But the original version of this article overstated several benefits. Saunas do not "detox" your body in a meaningful clinical sense, they do not burn hundreds of calories like a workout, and infrared saunas have not been proven universally superior to traditional saunas.
This updated guide breaks down what current research actually supports, how long to use each type of heat therapy, when post-workout heat may help, and when you should be cautious.
What Is Heat Therapy?
Heat therapy, or passive heat exposure, includes practices such as sauna bathing, steam rooms, and hot-water immersion. These methods raise skin temperature and, depending on the method and duration, may also increase core temperature and cardiovascular strain.
Heat-based bathing traditions have existed for centuries across many cultures, from Nordic sauna traditions to hot-spring bathing and the ancient Greeks.
Heat therapy has been used for centuries in many cultures. Modern research is now exploring whether repeated heat exposure can complement exercise by supporting cardiovascular function, thermoregulation, relaxation, and recovery.
It is important to distinguish observational evidence from randomized controlled trials. Frequent sauna use has been associated with lower cardiovascular and all-cause mortality in Finnish cohort studies, but association does not prove that sauna alone caused those outcomes.
Recent randomized-trial reviews of passive heating show a more mixed picture. Some studies report improvements in blood pressure, vascular function, or cardiorespiratory fitness, while pooled results across many cardiometabolic markers are inconsistent.
Heat Therapy Method 1: Sauna
A sauna can be used before or after exercise, but post-workout use is generally the more practical option because heat adds cardiovascular and dehydration stress.
If you use a sauna after training, rehydrate first and give yourself a few minutes to cool down from the workout before adding more heat.
Traditional Sauna vs. Infrared Sauna
Traditional Dry Sauna
Traditional saunas heat the surrounding air, commonly to around 150-195°F (65-90°C), although exact temperatures vary. Humidity is usually low unless water is added to heated stones.
The hot air raises skin temperature and increases blood flow, heart rate, and sweating. Core temperature may also rise depending on the heat, session length, and individual response.
Infrared Sauna
Infrared saunas use infrared radiation to transfer heat to the body while operating at lower air temperatures, often around 110-140°F (43-60°C).
They can feel more comfortable for people who dislike very hot air, but the claim that infrared saunas heat tissues "several inches deep" or are inherently more efficient for detoxification is not well supported.
Recent direct comparisons show that traditional sauna, infrared sauna, and hot-water immersion produce different physiological responses rather than one modality being universally superior. In one 2025 comparison, hot-water immersion produced the largest rise in core temperature, traditional sauna produced a smaller rise, and far-infrared sauna produced very little core-temperature increase under the tested conditions.
Bottom line: Choose the sauna you tolerate and enjoy. Traditional sauna has the strongest long-term observational evidence. Infrared sauna has some promising recovery and cardiovascular research, but it has not been proven categorically better.
We discuss this in more detail here: Infrared Sauna vs Traditional Sauna: Which Is Best?
How Long Should You Stay in a Sauna?
There is no single evidence-based duration that is ideal for everyone. Heat tolerance varies considerably.
Traditional sauna: A practical starting range is 5-10 minutes. Many healthy experienced users tolerate around 10-20 minutes per session.
Infrared sauna: Because the air temperature is lower, sessions are often somewhat longer, but longer is not automatically better. Around 15-30 minutes is a reasonable practical range for many users.
Leave immediately if you feel dizzy, faint, nauseated, confused, unusually weak, short of breath, or develop a headache.
There is also no requirement to use a sauna every day. One to several sessions per week can be reasonable depending on your health, heat tolerance, hydration, and goals.
What Are the Real Benefits of Sauna Use?
The strongest evidence and most plausible benefits include:
- Relaxation and well-being: Many people find sauna use calming and enjoyable.
- Cardiovascular response: Sauna exposure increases heart rate and skin blood flow while causing blood vessels to dilate.
- Potential blood-pressure benefits: Some repeated-heat studies report improvements in blood pressure, although pooled randomized-trial evidence is mixed.
- Possible cardiorespiratory benefits when combined with exercise: One randomized trial found that adding a 15-minute post-exercise sauna to an exercise program improved cardiorespiratory fitness, systolic blood pressure, and total cholesterol more than exercise alone in sedentary adults with cardiovascular risk factors.
- Heat acclimation: Repeated heat exposure may help the body adapt to exercising in hot environments.
- Possible recovery benefits: A small randomized crossover study in basketball players found that a post-exercise infrared sauna session reduced perceived muscle soreness and attenuated declines in explosive performance the following day.
There are also interesting observational findings linking frequent sauna bathing with lower rates of cardiovascular mortality and dementia. These findings are worth studying, but they should not be presented as proof that sauna use prevents heart disease, Alzheimer's disease, or premature death.
Related: Coronary Heart Disease and Exercise.
Sauna use may also help some people relax before sleep, but responses vary. See our guide to the Importance of Sleep.
What Saunas Do NOT Do
They Don't "Detox" You in the Way Wellness Marketing Often Claims
You can excrete trace amounts of certain substances in sweat, including some metals. But your liver and kidneys are the body's primary detoxification systems. There is no strong evidence that routine sauna sweating removes clinically meaningful amounts of environmental toxins or that this improves health outcomes.
Related: Is Sweating Good for You?
They Don't Burn 600 Calories in 30 Minutes
Your heart rate and energy expenditure may rise in the heat, but claims that sitting in an infrared sauna burns several hundred calories like vigorous exercise are not supported by good evidence.
The rapid weight drop after a sauna is primarily water loss. Once you rehydrate, that weight returns.
See our article on using the sauna for losing belly fat for more information.
They Are Not a Muscle-Building Shortcut
Heat exposure affects hormones and heat-shock proteins, but short-term changes in growth hormone, prolactin, testosterone, or heat-shock proteins do not mean sauna use directly builds meaningful amounts of muscle.
For muscle hypertrophy, progressive resistance training, protein intake, calories, and recovery remain the major drivers.
Other Types of Saunas
Barrel Saunas
A barrel sauna is primarily a design format rather than a separate physiological category. Most use a traditional electric or wood-burning heater. Their compact outdoor design makes them popular for home installations.
Smoke Saunas
Smoke saunas are a traditional Finnish design without a chimney. The room is heated by burning wood for hours, after which the fire is extinguished and smoke is ventilated before bathing. They are culturally important but uncommon outside Finland.
Heat Therapy Method 2: Steam Room
Steam rooms use moist heat. Temperatures are usually much lower than traditional saunas, commonly around 100-120°F (38-49°C), but humidity is close to 100%, which makes evaporative cooling much less effective.
This is why a steam room can feel extremely hot even at a lower air temperature.
Potential Benefits of Steam Rooms
Steam rooms can provide relaxation, temporary relief from feelings of muscular stiffness, and a strong heat stimulus. Humid air may also temporarily make nasal passages or congestion feel more comfortable for some people.
However, many of the dramatic benefits historically attributed to steam rooms, including "detoxification," immune-system boosting, or superior athletic recovery, have limited direct evidence.
Steam Room Risks
The main immediate risks are overheating, dehydration, dizziness, and fainting.
Public steam rooms also require good sanitation because warm, humid environments can support microbial growth. The original claim that poorly maintained gym steam rooms cause users to inhale pharmaceuticals or fluoride is not supported and has been removed.
If a steam room appears dirty, moldy, poorly maintained, or has a strong unusual odor, skip it.
Heat Therapy Method 3: Hot Tubs and Hot-Water Immersion
Hot-water immersion is another form of passive heat therapy, and in some laboratory settings it can raise core temperature more than sauna bathing because water transfers heat very efficiently.
According to the CDC, hot-tub water should not exceed 104°F (40°C).
Potential Benefits of Hot Tubs
Hot-water immersion may promote relaxation, temporarily reduce feelings of stiffness, and support sleep in some people. Emerging research also suggests repeated hot-water immersion may produce cardiovascular and heat-acclimation adaptations.
For post-exercise recovery, the evidence is mixed. Recent systematic reviews do not show hot-water immersion consistently outperforming other recovery methods for soreness or performance, although some studies report benefits for sleep quality or specific performance measures.
Hot-Tub Safety
The CDC recommends keeping hot-tub water at or below 104°F (40°C), avoiding alcohol before or during hot-tub use, and ensuring the water is properly disinfected.
Hot tubs can spread infections such as Legionella when poorly maintained because their warm, aerated water provides favorable conditions for bacterial growth.
Children under 5 should not use hot tubs. People who are pregnant should speak with their healthcare provider before using hot tubs, saunas, or steam rooms.
Sauna vs. Steam Room vs. Hot Tub
| Method | Typical Environment | Best Fit |
|---|---|---|
| Traditional Sauna | Hot, dry air | Relaxation, traditional sauna experience, strongest long-term observational research |
| Infrared Sauna | Lower air temperature, infrared heating | People who prefer gentler heat; some promising recovery research |
| Steam Room | Warm, nearly 100% humidity | People who prefer humid heat |
| Hot Tub | Hot-water immersion | Relaxation and hydrotherapy-style heat exposure |
There is no strong evidence that infrared sauna is universally superior to traditional sauna or that sauna is categorically better than hot-water immersion. Different methods create different physiological responses.
Related: Saunas vs. Steam Rooms.
Is Sauna Good After a Workout?
It can be, especially if you enjoy it and tolerate heat well.
A randomized trial found that adding 15 minutes of sauna immediately after exercise over eight weeks produced additional improvements in cardiorespiratory fitness, systolic blood pressure, and total cholesterol compared with exercise alone in sedentary adults with cardiovascular risk factors.
A separate small study in basketball players found that a single post-exercise infrared sauna session reduced muscle soreness and improved perceived recovery and next-day neuromuscular performance compared with passive recovery.
That is encouraging, but sauna should still be viewed as an optional recovery tool, not something you need after every workout.
Potential Risks of Heat Therapy
The main risks are dehydration, overheating, dizziness, fainting, and blood-pressure changes.
Be especially cautious or speak with a healthcare professional before using a sauna, steam room, or hot tub if you:
- Are pregnant
- Have recently had a heart attack or stroke
- Have significant heart disease, heart failure, severe aortic stenosis, or poorly controlled blood pressure
- Are taking medications that affect blood pressure, fluid balance, or heat tolerance
- Are sick, feverish, or already dehydrated
- Have consumed alcohol
Male fertility is another consideration. Repeated scrotal heat exposure can temporarily impair sperm production and sperm quality. If you are actively trying to conceive, frequent high-heat exposure may be worth discussing with a clinician.
A Simpler Post-Workout Sauna Protocol
The old version of this article prescribed a rigid four-week progression culminating in frequent 30-40 minute infrared sessions. There is no evidence that everyone needs to build toward those times.
A simpler approach is:
Beginners
- Cool down from your workout first.
- Drink water and replace fluids you've lost during training.
- Start with 5-10 minutes.
- Leave sooner if you feel uncomfortable.
- Use 1-2 sessions per week initially.
Once You Know You Tolerate Heat Well
- Traditional sauna: roughly 10-20 minutes per session.
- Infrared sauna: roughly 15-30 minutes per session.
- Frequency: 2-4 sessions per week can be reasonable if you enjoy it and recover well.
- You do not need to stay until a timer says you are finished. Symptoms always override the clock.
Drink according to thirst and your individual sweat losses. There is no universal requirement to drink exactly 2-4 cups before and after every sauna session.
A cold shower afterward is optional. It may feel refreshing, but it is not necessary to receive sauna benefits.
Frequently Asked Questions
How long should you sauna after a workout?
For many healthy adults, 10-20 minutes in a traditional sauna is a reasonable range. Beginners should start shorter. Leave immediately if you feel dizzy, nauseated, faint, or unusually weak.
Is an infrared sauna better than a traditional sauna?
Not clearly. Infrared saunas operate at lower air temperatures and may be easier to tolerate, while traditional saunas have a much larger body of long-term observational research. Direct comparisons do not establish one as universally superior.
Does sauna help muscle recovery?
Possibly. Some small studies report improvements in soreness, perceived recovery, or neuromuscular performance after infrared sauna use, but the evidence is not strong enough to call sauna essential for recovery.
Does sauna burn fat?
Sauna use causes sweating and temporary water-weight loss. It does not produce meaningful fat loss by itself. Long-term fat loss still depends primarily on energy balance, diet, and physical activity.
Does sweating detox your body?
Sweat contains trace substances, but the liver and kidneys are responsible for most detoxification. There is no strong evidence that sauna sweating meaningfully "cleanses" the body of toxins.
Can you use the sauna every day?
Some healthy experienced sauna users do, but daily use is not required. Your hydration, medical history, heat tolerance, medications, and total training stress all matter.
Is a steam room better than a sauna?
Neither is universally better. Steam rooms provide humid heat while saunas provide dry or infrared heat. Choose the environment you tolerate and enjoy.
How hot should a hot tub be?
The CDC recommends that hot-tub water never exceed 104°F (40°C).
Final Thoughts
Heat therapy can be a useful addition to a fitness routine, especially if you enjoy the relaxation and ritual of a sauna, steam room, or hot tub.
The most convincing case for sauna is not that it "detoxes" you, melts fat, or floods your body with muscle-building hormones. The better-supported argument is that passive heat exposure creates a meaningful cardiovascular and thermoregulatory stimulus, may complement exercise in some populations, and can simply be a relaxing way to finish a workout.
If you like sauna after training, use it. Start conservatively, hydrate, and pay attention to how you feel. You do not need extreme temperatures or marathon sessions to get value from heat exposure.
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