Sauna or Hot Tub for Sore Muscles: Which Helps More?

Short answer

Both can make sore muscles feel better, but neither is proven to make them heal faster. Small studies found that warmth after exercise, including one infrared sauna session, eased soreness. A hot tub adds buoyancy and jets at no more than 104°F. A sauna is hotter and makes you sweat more. Choose the one you enjoy and keep it short.

Sore legs after squats or a long run? Both a hot tub and a sauna can feel great. Here is what the research actually shows, how the two compare, and how to use either one safely after a workout.

Table of Contents

Hot tub vs sauna for sore muscles at a glance

Hot tub and sauna compared for post-workout soreness
	Hot tub	Sauna
Type of heat	Hot water around your body, often with jets	Hot air (traditional) or radiant heat (infrared)
Typical temperature	Never above 104°F (40°C); 100°F is considered safe for a healthy adult (CPSC)	Traditional about 150–195°F (66–91°C); infrared about 110–135°F (43–57°C) (Cleveland Clinic)
What it adds	Buoyancy and a massage-like feel from the jets	Dry heat; infrared feels gentler
Research on soreness	No direct hot tub studies found; heat wraps and warm leg baths eased soreness	Small infrared sauna studies; one found less soreness after strength training
Main cautions	Alcohol, drowsiness and drowning risk; check the water temperature	Fluid loss; Harvard Health suggests 15–20 minutes at most

What actually causes sore muscles?

The soreness that peaks a day or two after a hard or unfamiliar workout is called delayed onset muscle soreness (DOMS). It is often blamed on lactic acid, but the evidence does not support that. In a 1983 study, downhill running caused clear soreness, while harder running on the level did not. The authors linked DOMS to structural changes in the muscle from eccentric (lengthening) contractions. A 2003 review lists several possible mechanisms and concludes that more than one is probably involved.

This matters because heat cannot “flush out” soreness. At best it eases the pain and stiffness while your muscles recover on their own. The same review found that easy exercise relieves DOMS pain best, although the effect is temporary.

What the research says about heat and sore muscles

Heat wraps after exercise: in a study of 100 people who did squats, heat applied immediately afterwards helped preserve strength, and moist heat gave the greatest pain relief. These were chemical heat wraps, not a hot tub or a sauna.
Warm water before exercise: in a small trial, 11 men soaked their legs in 44°C water for 45 minutes before jumping exercises. Soreness and muscle damage markers were lower, but the authors say that did not necessarily mean better performance. That was a legs-only soak, so do not copy the temperature in a full-body hot tub.
Infrared sauna after strength training: in a 2023 crossover study, 16 male basketball players spent 20 minutes in an infrared sauna at about 43°C. Fourteen hours later they reported less soreness and had lost less jump height than after resting.
Infrared sauna, mixed results: an earlier study of 10 men found no recovery difference after strength training, only a slightly better jump 30 minutes after endurance exercise. A 6-week study of 40 female athletes found no extra muscle growth from infrared sauna use.

We found no controlled study comparing a hot tub with a sauna for soreness. Claims that a hot tub “reduces inflammation” usually trace back to a study of 10 overweight, inactive men that measured blood markers and blood sugar, not sore muscles.

When a hot tub may suit you better

Choose a hot tub if you like warm water, want the massage feel of the jets or find hot, dry air hard to tolerate. The water supports your body, which many people find relaxing after leg day. The US Consumer Product Safety Commission gives these rules: water should never be above 104°F, check it with an accurate thermometer, and do not drink alcohol, because heat and alcohol can cause drowsiness and drowning. People with heart disease, circulation problems, diabetes or blood pressure problems should ask their doctor first. Anyone taking medicine that makes them drowsy should not use a hot tub at all, the CPSC says.

More detail: traditional and infrared sauna vs hot tub and steam rooms vs hot tubs.

When a sauna may suit you better

Choose a sauna if you enjoy dry heat or already have one at your gym. An infrared cabin runs cooler than a traditional sauna. Cleveland Clinic suggests starting at about 110°F for 5 to 10 minutes and says the extra circulation may help ease soreness after activity. In a traditional sauna, Harvard Health notes that your pulse can rise by 30% or more and that you may sweat about a pint. Its advice: stay no more than 15 to 20 minutes, avoid alcohol, cool down gradually and drink two to four glasses of water afterwards.

See infrared vs traditional saunas, sauna after a workout and sauna vs steam room after a workout.

Heat or ice: when to skip both

Heat is for stiffness and general soreness. Cleveland Clinic recommends ice for fresh injuries, because heat can make a new injury feel worse at first. If a muscle hurts sharply during exercise, swells or bruises, treat it as a possible strain rather than ordinary soreness. Read is a sauna good for pulled muscles first, and see a clinician if it does not improve.

How to use a hot tub or sauna after a workout

Cool down and drink some water first. Wait until your breathing and pulse have settled.
Start short and mild, especially if you are new to it. You do not need to stay until a timer runs out.
Skip alcohol before and during the session (why alcohol and heat do not mix).
Get out if you feel dizzy, sick or unwell, and stand up slowly (dizzy or weak after the sauna).
Drink water afterwards and keep moving gently the next day. Easy movement helps soreness too.

Wondering about the order? See sauna before or after the hot tub, sauna before or after a workout and ice bath before or after the sauna.

Who should check with a doctor first

Ask your doctor before using a hot tub or sauna if you have heart disease, uncontrolled high blood pressure, circulation problems or diabetes, or if you take medicines that affect sweating or make you drowsy. If you are pregnant, the CPSC advises no more than 100°F in a hot tub. Read ACOG’s advice on saunas and hot tubs in early pregnancy.

Frequently asked questions

Is a hot tub or a sauna better for sore muscles?

Neither has been shown to be clearly better. A hot tub gives moist warmth, buoyancy and jets. A sauna gives drier, hotter air, and an infrared cabin is gentler. Small studies suggest warmth after exercise can ease soreness. Pick the one you find relaxing and can use safely.

Does a sauna help with muscle soreness?

It may help a little. In a 2023 study of 16 male basketball players, 20 minutes in an infrared sauna at about 43°C after strength training led to less muscle soreness the next day than resting. Studies are small, so treat it as a comfort tool, not a cure.

Does a hot tub help with muscle soreness?

Warm water and heat can ease the ache. In a study of 100 people, heat wraps applied right after exercise reduced soreness, and moist heat worked best. That was heat wraps, not a hot tub, so a soak is a reasonable comfort option rather than a proven treatment.

Is lactic acid the reason my muscles are sore?

Probably not. The soreness that shows up a day or more after a hard or unfamiliar workout is called DOMS. In a classic study, downhill running caused DOMS while harder level running did not. Researchers link it to small changes in the muscle, not to leftover lactic acid.

How hot should a hot tub be for sore muscles?

The US Consumer Product Safety Commission says hot tub water should never be above 104°F and calls 100°F safe for a healthy adult. It advises checking with a thermometer, because a thermostat can be off by up to 4°F. Pregnant people should stay at 100°F or below.

Should I use heat or ice on sore muscles?

For a fresh injury with swelling, Cleveland Clinic recommends ice first. Heat suits stiff, tight or lingering soreness. If a muscle hurts sharply, swells or bruises, it may be a strain, so skip the sauna and hot tub at first and see a clinician if it does not improve.

Sources

This guide summarizes published research and official guidance. It is not medical advice, and we did not run our own tests.