Unlocking the benefits of heat therapy  – Articles

When it comes to exercise and achieving fitness goals, it can be so easy for members to fixate solely on the effort put into a workout that they can forget to make time for other beneficial components of a fitness routine such as recovery. More specifically, heat therapy. With benefits that help stimulate hormone production, rid the body of toxins, improves cardiovascular health, and speeds recovery and injury rehabilitation, heat therapy is one recovery method that your workout routine can’t afford to miss out on. 

Heat and Hormones

Studies show growth hormone levels increase from two to five times normal levels[i]Growth hormone aids in recovery of muscle and from injury and is also a powerful fat loss hormone.  Exercise also elevates growth hormone levels, and heat and exercise seem to act synergistically, elevating growth hormone more than either do alone.[ii]

Norepinephrine levels rise to two to four times normal levels. This isn’t surprising since norepinephrine is secreted during stressful events, and the high heat is perceived as a stress.  Some hormones take up to 24 hours to return to normal.[iii] 

The effects of other hormones, such as cortisol, epinephrine, and thyroid are mixed. In some studies, they’ve increased, but in others, their levels have stayed the same. Testosterone levels appear to be unaffected.

Post-Workout and Injury Recovery

Injuries result in muscle damage, an immune response, and tissue breakdown. Immediately following an injury, joints are immobilized. Without movement, the muscles around the joints atrophy quickly. The loss of lean mass can become noticeable in as little as a week.  Heat therapy has benefits immediately following an injury or surgery and during the rehab period when strength and muscle mass are rebuilt.  Evidence suggests intermittent exposure to heat stress reduces the rate of atrophy, or muscle catabolism. 

It also reduces the buildup of free radicals, which are typically increased in immobilized muscle.[iv],[v] Free radicals or oxidative stress can cause damage to cell membranes, deplete the body’s glutathione stores, and compromise recovery rates. Heat therapy reduces the rates of oxidation and increases the rate of muscle tissue regrowth.[vi] Reducing free radical buildup remains essential when someone returns to the gym after injury since there is an increased rate of oxidation compared to uninjured muscles.  For example, lifting a five-pound dumbbell during rehab may create more oxidation than using 50 pounds with a fully recovered muscle on the same exercise.  

With heat therapy’s ability to enhance muscle growth and limit oxidation, it should also enhance the recovery process from exercise for healthy individuals. Combining heat therapy and the use of essential amino acids and curcumin is a nice way to speed recovery and support growth of muscle.

Heat therapy is also recommended for others with chronic pain, such as arthritis or other degenerative diseases.[vii]

Heat and Detoxification

A nice place to incorporate heat therapy into your routine is through using the sauna. The sauna is well-known for its ability to support detoxification. The sauna is superior to the steam room for detoxification because person sweat more due to the lower humidity and higher temperature.

A large amount of everyday toxins are released through sweat. This can be especially beneficial for those losing large amounts of weight. The body stores toxins in fat cells as a way to isolate them from the rest of the body’s cells. As someone loses body fat, toxins are released as well. Sweating helps to remove them from the body. To maximize the removal of toxins, periodically wipe off your sweat with a towel while you’re in the sauna.

One particular study on this topic found that about half of Utah police officers that were involved in methamphetamine drug busts developed varying levels of symptoms from exposure to the drug and its byproducts. Some symptoms were debilitating.  Following a nutrition, aerobic exercise and sauna therapy program, they saw a significant reduction in symptoms from the methamphetamine exposure.

Just don’t spend time in the sauna or steam room while drinking alcohol. You won’t reduce the effects of alcohol. If everything, you’ll amplify them with your elevated heart rate and reduced hydration.  Plus, if you’re wanting to do heat therapy the morning after drinking, you’ll want to think twice. Part of the reason for a hangover is dehydration so you could make things worse by sitting in the heat.

To fully appreciate the detoxifying effects of the sauna, consider pairing it up with a high-quality detoxification program.

Other Sauna Benefits

Sauna sessions may also enhance immune function and help prevent infection. In fact, regular sauna sessions have been shown to reduce the chance of catching a cold and may help those with respiratory dysfunction and support cardiovascular health.[viii],[ix],[x]  

Animal research suggests heat therapy improves insulin sensitivity.[xi] Insulin resistance affects a significant portion of the population and can lead to unwanted fat gain and increased risk of diabetes and cognitive issues.  Will the heat therapy get you leaner than diet and exercise? Of course not, but it can help maximize the results of a good nutrition and exercise program.

The Science of Heat Stress

Brief, intermittent periods of extreme heat creates a stress response in the body. Depending on the heat and humidity, core temperature starts to increase in 5-15 minutes. 

As temperature rises, the body responds by rerouting blood flow, speeding up heart rate, increasing blood vessel dilation and secreting a number of hormones.

Heat also stimulates heat-shock proteins, which are thought to play a role in the growth of muscle tissue. They also support the immune system by identifying proteins from cells that don’t belong in the body.

The principal of “more is better” doesn’t apply to the sauna or steam room. The goal is to reach a point where the heat becomes uncomfortable, but not push it to where you reach the verge of passing out.

Once a threshold is hit, about 10 minutes for most person, you can step out and get in a cold shower or pool. After cooling down, you can return to the sauna or steam room. You’ll respond faster the second or third time you enter the heat.

Again, the goal is to reach a point where the body senses a threat, NOT to see how long you can withstand the discomfort.  Your body will adapt to the heat over time, making longer durations more tolerable.[xii] You may need to start with just five minutes and add a minute each week until you’re able to tolerate 2-3 entrances of 15, separated by cool down periods.

Cooling Down

After using the sauna, make sure to take a cool shower to speed up the cool-down period and rinse off the toxins released through sweat. 

Also, without cooling down quickly, cortisol levels may continue to rise and individuals may feel fatigued for much of the day afterwards. If you feel overly tired following heat therapy, try cooling off faster with a colder shower. You should feel refreshed, not worn out from the sauna.

Sauna vs. Steam Room

The sauna has been used in Finland for over 2000 years. The temperature is kept at about 80°C (176°F) to 100°C (212°C). The extreme temperature is tolerable because the humidity is kept very low.

On the other hand, the steam room is much more humid and has a lower temperature. The steam room is usually 40C (104°F) to 70°C (158°F). Because of its high humidity, most person cannot tolerate being in the steam room as long as they can the sauna.


Sessions in either include two to three entrances of 5-15 minutes, with cooling-off periods between each entrance. The average person loses about 0.5 liter of water in a sauna session, but sweat loss in the steam room is usually less. [xv]

The differences in temperature and humidity do create some differences in effects in the body.

With the low humidity level, the sauna allows for a greater amount of sweating. This is why person can normally stay in the sauna longer. Because they can sweat more, they’re able to cool themselves better than they could at higher humilities.

Even though the temperature is higher in the sauna, the humidity in the steam room causes a faster rise in core body temperature. The high level of humidity in the steam room does not allow for efficient perspiration. Sweat cannot evaporate because of the high humidity.

The sauna or steam room should both enhance recovery, support immune function and provide cardiovascular benefits. These changes occur as a result of the body becoming overheated. person often reach a threshold faster in the steam room, where the humidity makes it difficult to cool one’s self.

For those seeking relaxation and detoxification, the sauna is probably a better option, as it allows for more sweating, which supports detoxification, and is more tolerable, which helps with relaxation.

Either one – the sauna or the steam room – would be a wise addition to a health and fitness program. Work it into your schedule two to three times per week for two months and see if you notice a difference.

 – Written by Flourish staff

(Article was updated since original publication on Core3

This article is not intended for the treatment or prevention of disease, nor as a substitute for medical treatment, nor as an alternative to medical advice. Use of recommendations in this and other articles is at the choice and risk of the reader.