Biohacking refers to a method of changing your body’s chemistry and physiology through self-experimentation with the goal of improving health, longevity, and vitality. If you read our first post on the biohacking benefits of cold exposure, you’ll know that popular ‘Biohackers’ like Dave Asprey, Ben Greenfield and Tim Ferriss have been making biohacking practices popular since around 2005, and the list of things you can ‘biohack’ is almost endless. In part 2 of our series on biohacking, you’ll learn all about another incredibly effective, simple, accessible and seriously beneficial practice to add to your health toolkit; heat therapy, heat ‘stress’ and the use of saunas.

What is heat therapy?

One of the most popular biohacking practices is cold immersion therapy, and its partner heat therapy is one of the other best biohacks you can start benefitting from today. Known as ‘heat therapy’, ‘thermotherapy’, heat exposure or ‘heat stress’, this protocol is all about raising your body temperature to elicit specific benefits, often done in a sauna, although there are other ways of practicing thermotherapy which you’ll learn all about in a moment. The myriad benefits of heat and sauna use include improvements in body composition, lowering inflammation and blood pressure, improvements in cardiovascular health and longevity, improvements in lipid levels, as well as being a great way of reducing stress and enhancing the immune system. [1] [2]

How to practice heat exposure

Before we explore the specific benefits of heat exposure, and how you can use heat stress to vastly improve your health, it’s important to note how vital it is to practice this method safely. Check with your healthcare provider if you’re concerned about using heat exposure, and if you’re pregnant, ill, elderly or have an underlying health condition. Always make sure you experiment with heat exposure within the parameters we’ll discuss today, listen to your body, and stay hydrated, which we’ll also tell you all about.

Different types of heat exposure

• Sauna: Most of the research we’ll reference in this blog was conducted via saunas. The benefits of saunas include improved circulation, reduced pain, reductions in stress levels, and studies conducted on both men and women even show that spending between 5 to 20 minutes in the sauna 2 to 3 times per week can result in a 27% reduction in risk of dying from a cardiovascular event. Those in the studies who went in the sauna 5 to 7 times per week benefitted even more, with a 50% reduction in risk of dying not just from a cardiovascular event, but from all-cause mortality too. [3]

• Infrared Sauna: An infrared sauna uses light to make heat, usually with either near-infrared, far-infrared or a combination of both. Whilst the benefits of infrared light include enhancing detoxification, improving skin health, reducing pain and tension, as well as reducing side effects of diabetes and lowering blood pressure, the sauna side of infrared saunas doesn’t usually get hot enough to elicit the benefits of heat exposure we’ll cover today.

• Exercise: You don’t have to join a gym or buy a home sauna to get the benefits of heat exposure. Exercise that raises body temperature significantly (but safely) also has big benefits. ‘Heat training’ is even a term used in the athletic community to describe a form of somewhat intense exercise done at high temperatures. The benefits of heat training include triggering a series of adaptations that can greatly improve your endurance, [4] aerobic exercise performance, and an increase in the body’s levels of haemoglobin – the essential protein in your red blood cells that carries oxygen to organs, muscles and tissues. [5] Exercising on a hot day, wearing a specific ‘sweat suit’ whilst jogging, or practicing hot yoga can all help you get the benefits of exercise-induced heat therapy.

• Hot Tub: Relaxing, sleep-enhancing and great for releasing muscular tension, hot tubs are another way you can practice heat exposure by immersing your body up to the neck. The water should be uncomfortably warm but completely safe in order to use this method as a ‘heat stress’.

Sauna Vs Steam Room: Which is best?

One of the most searched questions on the benefits of heat therapy is whether saunas or steam rooms are better. The answer? The research shows that both share pretty much the same benefits and risks,[6] so you can choose whichever is most accessible to you. As we mentioned previously however, most of the research has been done on dry saunas, but there are many benefits of steam rooms, including:

• Clearing congestion
• Relaxing muscles
• Reducing Stress
• Lowering Blood Pressure
• Enhancing skin moisturisation

Benefits of Heat Stress: Why Are Saunas Good For You?

So, what are the benefits of heat stress, and why are saunas good for us? Much of this comes down to the way cold exposure benefits us too; it’s all about giving the body a ‘good stress’, also known as ‘eustress’ or a ‘hormetic stressor’. Whilst sitting in the sauna can get uncomfortable, it’s the discomfort that actually gives the biggest benefits – although remember that safety is absolutely vital when you’re in a sauna, and you should build up gradually. Regular sauna use activates heat shock proteins, which make our cells more resilient and adapted to damage and stress.[7] Heat shock proteins are a family of proteins produced by cells when we’re exposed to a stressor, and they help promote the survival of healthy cells, whilst aiding in reducing the amount of ‘senescent’ cells the body has. Senescent cells are those which have aged and permanently stopped dividing, but which don’t die. When excessive amounts of these old senescent cells build up in the body for a prolonged amount of time, they can increase the risk of developing tumours, chronic inflammation, and types of cancer. [8] [9] Other ways to clear out senescent cells include exercise, fasting, as well as using a combination of natural compounds including quercetin.

Another key benefit of saunas and deliberate heat exposure is the incredible benefits this biohacking tool has for cardiovascular health. As you’ll remember from the study we mentioned above; research shows that 2 to 3 sauna sessions per week between 5 to 20 minutes can reduce the risk of death from a cardiovascular event by 27%, and that more frequent sauna visits per week increases the benefit to 50%. These benefits are partly thanks to the way saunas actually mimic cardiovascular exercise by increasing heart rate, improving circulation, exercising the vascular system. This isn’t an excuse to skip the gym and head straight for the sauna, but it’s good to know that there are more ways to improve your heart health than running on the treadmill…

4 Big Benefits Of Heat Exposure & Sauna Therapy

Here, we’ll look at some of the best benefits of heat exposure, and why saunas are so good for us.

1. Heat Therapy For Detoxification

The primary way humans release excess body heat is via sweating, and if you’re a regular sauna user, you’ll know it can get pretty sweaty in there… Sweating is also a key way the body detoxifies itself, and it helps rid the body of some specific problematic toxins. Sweating can help clear the body of heavy metals, such as lead, chromium, copper, zinc, and cadmium. [10] Whilst some heavy metals are important for health, its well known that high levels of heavy metals in the body can cause serious damage to organs and hormones. Research shows that the more frequent your sauna sessions are, the more efficient your body becomes at sweating. Allowing your body to sweat properly is vital, so ensure you’re not wearing antiperspirant deodorant (which is likely to contain heavy metals too) before your heat exposure session.

2. The Benefits of Heat Stress For Weight Loss & Metabolism

If you read our biohacking blog on the benefits of cold exposure, you’ll know that cold immersion can significantly boost metabolism and levels of brown fat. Brown fat is a metabolically active type of fat that helps improve metabolism, as well as enhancing mitochondrial health. You can do this most effectively by spending between 5 to 20 minutes in the sauna, then dipping into cool water or a cold plunge, [11] although research also shows weight loss benefits after a 20 minute session separated into two sets of 10 minutes with a 5 minute break in between.[12] Experts also estimate that a hot sauna session can boost metabolism by around 20-30%, which will last for the length of time you’re in the sauna, and for a couple of hours afterwards. For longer-lasting benefits, try getting into the sauna several times a week.

3. Saunas For Injury Healing & Increasing Growth Factor

When it comes to huge increases in specific hormones, it seems that the ‘shock’ factor of an intentional heat stress practice can provide significant benefits, specifically to growth hormone. Human growth hormone (HGH) is important for growth and development, maintaining normal body structure, healing injuries, healthy metabolism, keeping blood sugar levels balanced, and aiding in recovery and muscle building after exercise. General sauna use can help enhance growth hormone, but to see the biggest benefits, you’ll need to use heat exposure very specifically: Research shows that four 30-minute-long sauna sessions with a cool down period in between over the course of a day can increase growth hormone by 16-fold! [13] The first time the study participants did this protocol, they received this marked rise in growth hormone, but doing this type of practice several times a week shows less and less benefit due to the body adapting to the heat. If you want to significantly boost your levels of growth hormone, practice those longer sessions a maximum of once per week to prevent adaptation, and without eating food for 2 to 3 hours beforehand for even greater benefits.

4. Heat Therapy For Reducing Cortisol

When released at its proper time (around waking in the morning) and in proper amounts, cortisol is a necessary and beneficial hormone. When chronically elevated however, we experience prolonged stress, which is detrimental to both mental and physical health. The good news is that heat therapy and sauna use can help reduce cortisol and improve relaxation. Using a sauna in different ways can elicit different effects, and help decrease cortisol levels. Research shows a 12 minute sauna session at a temperature of 90C followed by a 10 minute cooling down period in 10C water can notably reduce cortisol levels. [14] The best time to do this type of practice would be in the late afternoon or evening, since cortisol levels should naturally drop in the evening in preparation for sleep. A heat therapy session via a sauna, steam room or hot bath in the evening can also help improve sleep, as when you get out of the heat, the brain triggers body temperature to start cooling down, which in turn helps stimulate the release of melatonin. Melatonin is known as the ‘sleep hormone’ and is an essential antioxidant that helps us get to - and stay - asleep.

Now you know the benefits of heat exposure and saunas, here’s how to start creating your own protocol for the benefits you want to see.

What is the best temperature for sauna and heat exposure?

The most common temperature referenced in these studies was between 80C and 100C. As always however, the most important factor is that the temperature is safe! Just as with cold therapy, your session should be uncomfortably, yet safely bearable. Your heat tolerance, health and metabolism will also determine how hot you can handle it. Start at 80C if you’re able to control the temperature, and build up gradually from there.

How long should I be in the sauna for?

Most research shows benefits from between 5 and 20 minutes in the sauna. Again, it’s all about what is right for you. Two sessions of 10 minutes separated by a cooling break may be the optimal way for you to get 20 minutes of intentional heat stress, but build up slowly and don’t stay longer than you can reasonably tolerate.

The Benefits of Contrast Therapy: Combining Hot & Cold

To get the best of both heat and cold, contrast therapy has been shown to greatly enhance circulation, treat oedema and stiff joints, lower inflammation, and reduce muscle spasms. [15] The research also shows alternating between heat and cold can lessen muscle fatigue, and decrease lactic acid build-up after exercise, and be much more beneficial for speeding up recovery from injuries than the use of ice alone. [16] To practice contrast therapy, alternate between hot and cold water, or divide your sauna session up with brief periods in a cold shower or plunge pool. You can also benefit from combining the benefits of cold immersion with the benefits of heat exposure over the course of your weekly routine; Just as research shows the optimal threshold of cold immersion seems to be 11 minutes per week, the threshold of heat exposure is around 57 minutes total per week, divided into several sessions.

So, now you know the benefits of heat therapy and sauna use, as well as how to use cold immersion for greater health and vitality. After your heat session, remember to rehydrate properly, by adding electrolytes to your water. You can get your electrolyte balance supplements HERE, which will help replenish the vital balance of sodium, magnesium and potassium you’ll need after excessive sweating. Electrolytes are also important to include on a low carb or keto diet plan, and can greatly enhance sleep too.

Sources

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• [2] Pilch W, Pokora I, Szyguła Z, Pałka T, Pilch P, Cisoń T, Malik L, Wiecha S. Effect of a single finnish sauna session on white blood cell profile and cortisol levels in athletes and non-athletes. J Hum Kinet. 2013 Dec 31;39:127-35. doi: 10.2478/hukin-2013-0075. PMID: 24511348; PMCID: PMC3916915.
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• [9] Zeng S, Shen WH, Liu L. Senescence and Cancer. Cancer Transl Med. 2018 May-Jun;4(3):70-74. doi: 10.4103/ctm.ctm_22_18. Epub 2018 Jun 29. PMID: 30766922; PMCID: PMC6372122.
• [10] Kuan WH, Chen YL, Liu CL. Excretion of Ni, Pb, Cu, As, and Hg in Sweat under Two Sweating Conditions. Int J Environ Res Public Health. 2022 Apr 4;19(7):4323. doi: 10.3390/ijerph19074323. PMID: 35410004; PMCID: PMC8998800.
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