The Vitruvian

Understanding Sauna Therapy: Infrared vs. Traditional Finnish Saunas

Finnish and infrared saunas share the same hormetic core — but temperature, depth, and nervous system response determine which protocol earns its place in your recovery practice.

Video·Dr. Connor Wolfe·11 min read·June 2026

Both promise heat, sweat, and recovery — but the differences in temperature, mechanism, and outcome matter more than most people realise.

What Heat Does to the Body

Step into any sauna — infrared or Finnish — and the body begins the same conversation. Core temperature rises. Heart rate climbs. Blood moves toward the skin to shed heat and stabilise the internal environment. This heat stress response is not a side effect to be managed; it is the mechanism itself, and both sauna types trigger it, though at different temperatures, speeds, and depths of tissue engagement.

Within that rising temperature, the body produces a short-term spike in reactive oxygen species. In chronic excess, these molecules accelerate cellular damage; in controlled, acute doses, they initiate something more purposeful: a hormetic response. The body reads mild stress as a signal to prepare, activating repair cascades that leave tissue more resilient than before the exposure. Hormesis — the principle that measured, deliberate challenge produces long-term biological strength — is what elevates sauna from passive warmth to intentional practice. The body asked to adapt, adapts; and it adapts in excess of the original demand.

low levels of acute or short-term reactive oxygen species are actually good at helping to signal that hormetic response within the body

One of the most consequential responses to heat exposure is the release of heat shock proteins. These molecular chaperones perform essential cellular maintenance: identifying misfolded proteins, supporting their repair or clearance, and preserving the structural integrity of biological processes across every organ system. Consistent heat exposure raises baseline levels of heat shock proteins, creating a sustained cellular defence that supports recovery, protects against protein aggregation, and reduces the risk of the neurological decline associated with impaired protein clearance. The benefit does not announce itself in any single session; it compounds across weeks and months of deliberate practice.

Heat also activates NRF2 — the body's master antioxidant switch. When this transcription factor engages, it upregulates a broad network of genes responsible for neutralising oxidative stress and supporting metabolic detoxification. The result is a gradual reduction in the cellular burden that accumulates from environmental toxins, chronic stress, and the demands of modern life. Over a sustained sauna practice, NRF2 activation contributes to improved energy, clearer focus, and the kind of cellular integrity that expresses itself as long-term wellbeing.

Two further regulators — AMPK and PGC1-alpha — respond to heat stress by driving mitochondrial biogenesis: the production of new mitochondria and the enhancement of existing ones. As mitochondrial capacity expands, energy production becomes more reliable, metabolism improves, and the body's capacity for recovery deepens. You feel this as steadier energy between sessions, improved endurance, and a metabolic vitality that builds gradually over time. These responses — heat shock proteins, NRF2, AMPK, PGC1-alpha — are shared by both sauna types; what differs is the depth and speed with which each format draws on this shared biology.

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What's going on? Welcome back. Today we are talking all things sauna and we're going to be comparing specifically infrared saunas to the traditional finished sauna. So, I'm sure you've seen the infrared sauna popping up all over the country in wellness spas and celebrity homes. And you may be wondering, what's the difference between an infrared sauna and a finished sauna? And do the infrared saunas really give me those robust changes to longevity, metabolic health, cardiovascular health that a finished sauna does? Well, before you run out and jump into a fitness membership that includes infrared sauna and before you spend thousands of dollars on putting one in your home, let's dive into the differences between the two of them to make sure that you're actually getting the benefit that you're looking for when it comes to your health goals. So, let's just talk about some blanket across the board physiological responses that start to happen when you go through deliberate heat exposure. And this is not specific for the high heat saunas. It's not specific for the infrared sauna. This is just your body's adaptation to heat kind of across the board. So, the first thing that's going to happen is we're going to get that increase in our body temperature and

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this is going to create a heat stress response within the body. We're going to start to create adaptations that are designed to cool that body temperature back down. The biggest things we're going to start to see are an increase in our heart rate and an increase in skin vasoddilation so that we can start to shuttle blood around and ex get that heat out of the body. The other thing we're going to start to see is a short-term increase in reactive oxygen species. Now react reactive oxy oxygen species do create a lot of oxidative stress on the body which we would typically associate with being bad. However, low levels of acute or short short-term reactive oxygen species are actually good at helping to signal that hormetic response within the body. This is going to start to signal a couple of pathways and cascades that happen within the body that help create these adaptations over time. We're going to get an increase in heat shock proteins. Those heat shock proteins are amazing at helping to kind of deal with protein misfolding and clearing excess proteins out of the body. We're going to get an increase in NRF2, which is an

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antioxidant kind of detox switch that has a lot of really good health benefits within the body as well. We're going to see an increase in EMPK and PGC1 alpha, which both help increase mitochondrial activity and metabolism. So, these health increases are all happening under the surface as we start to go through that deliberate heat exposure. And all of these happen regardless of whether we're using an infrared sauna or a high heat sauna. It's just how quickly are they happening and which ones are more robust for the specific type of sauna that we're using. What this is going to react in is an result in in the body is an increase in cardiovascular support and stability. we're going to see an decrease in inflammation and an increase in detoxification activity within the body. Now, we don't want to just say that sauna increased detox across the board because they're not exactly doing that. There's two different phases that we have when it comes to detox and sauna is going to help support both of those phases, but it's not to say it's just creating a blanket detox response is not

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actually correct. So, the first phase is we've got to mobilize. We've got to pull the toxins out of the tissues that they're stored in. And then we've got to excrete those toxins through either the urine, the stool, or through sweat. So, increasing blood flow to the surface tissues and the muscles is going to start to help mobilize some of those toxins throughout the body. And then increasing sweating is going to help with eliminating the toxins from the body as well. So, we are going to get some detox response that's happening there. But there's two different types of detox that are kind of happening and those vary slightly between infrared saunas and the high heat saunas, right? Um, so it's important to understand if detox is the goal, which type of sauna do we want to use? So let's lay the foundation for what the traditional Finnish sauna is. This is the type of sauna that we've had for thousands of years. It's what they use over in Finland, Iceland, Sweden, all those really cold places over in Europe. And what this is is a very high heat sauna. So this is going to be anywhere between 100 or 80 to 100° C converts about 172

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to 212° F. Now this really high heat is going to create a large robust short-term heat stress response within the body. We're going to use this for about 15 to 30 minutes. Now with the finished sauna, the research really supports great cardiovascular risk benefits. It shows a decrease in cardiovascular morbidity by about 65% when we're using that sauna 40 four to seven days a week. And it's going to show a really robust decrease in Alzheimer's and dementia risk as well. So that cardiovascular decrease or the allcost cardiovascular mortality risk is going to decrease by 50 to 70%. Um, and then we're going to see a 65% decrease in Alzheimer's and dementia again when we're using that high heat finish sauna over about 4 to 7 days a week on average. And there is a dose response with this as well. So, we do want to make sure that we are using it on a repetitive basis. Now, this fast rise is going to create a stronger cardiovascular benefit um and it's going

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to cause more of those heat shock proteins to be respond or released. When we compare this to an infrared sauna, infrared saunas work a little bit differently. So, they're not going to have that really high heat getting up into the 170 and 180 200s. The heat in an infrared sauna is typically going to be somewhere between 130 to 150 degrees. So, because of that, you are going to have to stay in the sauna for significantly longer and there is going to be a slower ramp up in heart rate and a slower ramp up in those heat shock proteins being released. However, we can still create that heat shock protein release. it's just not going to be as robust as if we were using a finished sauna. Now, where infrared saunas have a cool edge is that they do have that near mid and far infrared light that's being excreted at the same time. That near mid and far infrared light is going to actually penetrate within the skin an inch to two inches deep. And this is going to have a big impact on mitochondrial function. It's going to support fat mobilization and toxin mobilization from the fat tissue. It's going to kind of heat us up from the

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inside out. So, while it is not going to be as hot, it's going to take longer to sweat, we are getting that deep penetrating heat from those near, mid, and far infrared wavelengths of light. Um, this is going to be more tolerable. So, a lot of people who have less tolerability to heat are going to benefit from this. It's going to be really good for people with chronic illnesses, a lot of pain, um, athletes and working for recovery specifically. Um, and then it is going to help with the stress response as well. When we look at comparing the finished sauna to the infrared sauna, specifically with that stress response, because of how hot that finished sauna is, because of how fast your heart rate's going to elevate, this is going to put you into more of that fight orflight stress response. The infrared sauna being at a lower heat that you're in for a longer period of time is going to stimulate more of that rest and digest parasympathetic response. So if we're trying to support the parasympathetic response come out of that fight or-flight response, something like an infrared sauna is going to really help to support that stress

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response more so than something like a high heat finish sauna. The other big differences here is the utilization. So like I said, they do have a lot of similar benefits, some more robust than others. The utilization is going to be a big difference here as well. So, this can play a role kind of in when it comes to your health goals, which we're going to talk about in just a second, of which sauna you may want to choose. So, the temperature, obviously, a finished sauna is much hotter than an infrared sauna, about 172 to 212 degrees compared to 130 to 150°. The duration of time that you have to be in them because of the heat difference is different as well. So, a finished sauna, you're going to want to be in that for about 15 to 30 minutes to unlock those maximum benefits. Whereas an infrared sauna, you're going to need to be in that for about 30 minutes to 45 minutes. The benefits are going to change slightly. So an infrared sauna is going to be much better for metabolic health, for impacting the mitochondria, and for recovery, chronic illnesses, pain, things like that. Whereas that high heat

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finish on it is going to be much better if you're trying to increase cardiovascular output or decrease cardiovascular mobility or morbidity, increase longevity um and in decrease your risk of dementia or Alzheimer's. So again, both of them have really cool benefits, but they're going to be slightly different. And then of course the mechanism is a little bit different as well and more so just with the robustness of those heat shock protein responses, the changes in heart rate, cardiovascular output, vasoddilation, things like that. Um, so how do we use these? If you want to do the finish sauna, that high heat sauna, typically what we're going to want to see is about four to seven times per week. One of the best times to do this is going to be immediately following exercise. The heart rate goal here is we want to get that heart rate up into the 150 beats per minute area. That's how we're going to know we're getting that cardiovascular benefit from it. A lot of the heat shock proteins start to really be released once that core body temperature gets up to 101.3. Um, so we want to see that increase in blood pressure or in uh that increase in

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core body temperature. And then you don't have to do this, but what a lot of people will do, especially over in Finland, Sweden, all those places, is they'll do kind of in and out sort of a thing. So, they'll go into the sauna for 15 minutes. They'll come out, they'll do a cold rinse, and then they'll go back into the sauna again. And as heating and cooling does have a little bit of an increase in the adaptation that we're going to start to see with that finished sauna. Next week, we're going to talk all about different ways that you can kind of program your sauna usage and talk about the difference between hot and cold exposure and contrast therapy, when to use infrared or finish saunas around exercise, that type of stuff. So, stay tuned for next week's video. But we're going to talk a lot more about that. And then for doing infrared sauna, infrared sauna is going to be more of the three times a week to start with and then we're going to ramp that up to six to seven times a week. So you can use the infrared sauna a little bit more frequently. Um but because you're in it for a lot longer, you've got to make sure that you're really hydrating, taking in your electrolytes. And there is going to be a time constraint. Not everybody has 45 minutes every single

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day to sit in the sauna. And so if time is a factor, the finished sauna may be something that's a little bit better for you. Um, we're going to want to, like I said, drink plenty of electrolytes. And then within that infrared sauna, we're going to want to make sure that we're looking for um the sweat response to start happening. We're going to be looking for that elevated heart rate. And then you may start to get a little bit fatigued, which tells you that your time is coming to the end. We don't want to really push too far past that fatigue setting in within that infrared sauna environment. Um, so contraindications here, there's not a whole lot of contraindications when it comes to either type of sauna. Obviously, if you have some sort of significant heat exposure issue, we would want to be very, very careful with the saunas and probably lean more towards that infrared sauna at a lower heat threshold. If you've got uncontrolled blood pressure issues, there is a huge cardiovascular response that happens within that sauna. So, you've got to be very careful with that. And then, of course, if you are pregnant, you've got to be careful with the sauna as well. Um, or if you're breastfeeding, because of that, sweating is going to decrease fluid volume. it

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may impact breast supply or breast milk supply as well. Um, and the other thing is if you have an active infection, you want to make sure you're being careful with that heat exposure as well. Um, so let's just talk about kind of a brief summary here of which ones are best to use based on kind of what your health goal is. So, if your main health goal is decrease cardiovascular risk and morbidity over time, improvements with Alzheimer's or dementia risk, the finished sauna is really going to be the primary thing that you're going to want to look for there. Um, doesn't mean that the infrared sauna isn't going to have those benefits, but the finished sauna does have the most robust research supporting those benefits. Again, that 50 to 70% decrease in cardiovascular death and the 65% decrease in dementia or al Alzheimer's risk with that finished sonic exposure four to seven times a week. If you're looking for more chronic illness support, pain management support, athletic recovery, this is more where that infrared sauna is going to play in. So again, both have very good

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benefits, but it's just utilizing the one that's going to help you support the goals that you're looking for the most. Uh, so I hope this video was helpful. I'd love to hear what you guys have more questions with, specifically when it comes to saunas. You can drop any of those questions below and I'll make sure to get those answered on a future video. Again, next week's video is going to cover more about when to use each type of sauna, specifically around exercise and programming. Uh, and then some of the some of the things that we can start to see improvements with when we're using contrast sensitivity. So, going from heat to cold exposure. So, we look forward to seeing you guys. If you like this, if you felt like you got value from this, like the channel, subscribe to me, and I look forward to seeing you guys next time. [Music]

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The Finnish Sauna: Intensity as Protocol

The Finnish sauna is the original protocol, and its defining quality is intensity. Temperatures run between 80 and 100 degrees Celsius — 172 to 212 degrees Fahrenheit — producing a rapid, forceful physiological response. Sessions last 15 to 30 minutes. At that heat, the body adapts at pace: heart rate rises steeply, core temperature moves with urgency, and the entire cardiovascular system is recruited at once. The traditional practice, refined across centuries in Finland and Scandinavia, is now validated by some of the most compelling longitudinal health data available.

The evidence for Finnish sauna in cardiovascular and cognitive health is among the most compelling in the longevity literature. Regular sessions — four to seven per week — are associated with a 50 to 70 percent reduction in all-cause cardiovascular mortality and a 65 percent reduction in the risk of Alzheimer's disease and dementia. These are not marginal findings; they are among the most robust associations between any single lifestyle behaviour and long-term health outcomes in current research. The relationship is dose-dependent: frequency drives the benefit, and the consistency of practice determines how fully it accrues.

The mechanism behind these outcomes lies in how the Finnish sauna loads the cardiovascular system. The steep temperature rise activates the sympathetic nervous system, driving heart rate toward 150 beats per minute — a cardiovascular demand comparable in intensity to moderate aerobic exercise. Applied consistently over time, this load drives meaningful vascular adaptation: improved arterial elasticity, reduced resting blood pressure, and the cardiac resilience that sustains performance and energy across decades. The sympathetic activation also sharpens alertness during the session, producing the mental clarity that practitioners identify as one of the protocol's most immediate rewards.

The cardiovascular challenge of a Finnish session also trains something less visible: the nervous system's capacity to regulate itself under pressure. The cycle of activation inside the sauna and recovery outside it — repeated across hundreds of sessions — develops a precision in the stress response that extends well beyond heat tolerance. What the body learns, over time, is to engage challenge with efficiency and return to equilibrium with discipline. Regularity deepens this effect. This is resilience in its most fundamental form, practiced without abstraction and measurable in every dimension of daily performance and clarity.

Many Finnish and Scandinavian practitioners amplify these effects through contrast cycling — moving from the sauna to a cold rinse or plunge, then returning to the heat. This deliberate alternation forces the cardiovascular system through repeated activation and recovery cycles within a single session, compressing multiple adaptation signals into concentrated practice. Cold exposure releases norepinephrine, producing heightened focus and driving further circulatory adaptation that supports mood, recovery, and long-term cardiovascular health. The combined effect exceeds what either thermal stressor produces alone. Contrast is not an optional enhancement; for many, it is the completion of the protocol.

Infrared Sauna: Depth Over Intensity

The infrared sauna operates on different principles. Ambient temperatures sit between 130 and 150 degrees Fahrenheit — lower than the Finnish benchmark, and deliberately so. Sessions extend as a result: 30 to 45 minutes, rather than 15 to 30. In a Finnish sauna, elevated air temperature alone drives the heat stress response. In an infrared sauna, near, mid, and far wavelengths of light penetrate the skin directly, reaching tissue that surface heat alone cannot access and initiating a different class of cellular adaptation.

Those wavelengths penetrate one to two inches below the skin surface — well beyond what ambient heat alone can reach. This depth allows infrared energy to interact directly with tissue and fat cells, stimulating mitochondrial activity and supporting the mobilisation of toxins stored in adipose tissue — processes that directly support recovery and metabolic renewal. The heating process works from the inside out rather than the outside in. That distinction changes what the session accomplishes and makes infrared well suited to goals that require deep cellular engagement rather than acute cardiovascular intensity.

At the cellular level, far infrared light activates mitochondria directly, improving their efficiency and supporting better energy production across tissue. This makes infrared sauna well suited to metabolic support, fat mobilisation, and the cellular repair work that underlies recovery from intense training or chronic physical stress. For those managing persistent pain, chronic illness, or the reduced recovery capacity that follows injury or age, infrared offers meaningful support without the thermal demand that high-heat protocols require. The lower ceiling is not a concession; it is a design aligned precisely to these goals.

That near mid and far infrared light is going to actually penetrate within the skin an inch to two inches deep.

Where the Finnish sauna activates the sympathetic nervous system — driving alertness, cardiovascular urgency, and the focused edge of fight-or-flight — the infrared sauna draws the nervous system toward the parasympathetic. The slower heat ramp and lower ambient temperature engage the rest-and-digest orientation that underpins deep recovery, digestion, and sustained calm. Sessions feel meditative rather than demanding. The physiological outcome — reduced cortisol, improved sleep quality, and a measurable shift toward stillness — reflects this orientation entirely, and makes infrared the more restorative choice for those whose systems need equilibrium before further activation becomes useful.

These qualities make infrared the preferred entry point for recovery-focused athletes, individuals managing chronic conditions, and anyone building toward a heat practice from a lower baseline. Heat tolerance develops steadily at these temperatures, and the longer session duration allows cardiovascular adaptation to occur without abrupt demand. The deep tissue penetration supports both the mobilisation phase of detoxification and the cellular repair that follows sustained training. Infrared does not replicate the Finnish sauna's cardiovascular intensity — it was built to restore, not to challenge, and that distinction defines its place in a complete recovery protocol.

Choosing Your Protocol

Sauna's detoxification effect operates in two phases, and understanding them clarifies which format to prioritise. The first is mobilisation: heat drives blood to the surface tissues and muscles, drawing stored compounds out of the adipose tissue where they accumulate. The second is excretion: sweating then eliminates those mobilised substances through the skin. Both sauna types support both phases, but infrared's deeper tissue penetration makes it more effective at mobilisation, while the intense sweating of the Finnish session drives more efficient excretion. The goal shapes the protocol.

For cardiovascular longevity and cognitive protection, the Finnish sauna is the primary protocol. The evidence is built on high-heat, high-frequency use — four to seven sessions per week, ideally following exercise when the cardiovascular system is already engaged and responsive. Targeting a heart rate of 150 beats per minute within the session ensures the cardiovascular load is sufficient to drive adaptation. Core temperature reaching 101.3 degrees Fahrenheit marks the threshold at which heat shock protein release becomes most significant — the cellular repair response that underpins recovery and longevity. These are not arbitrary benchmarks; they are the physiological signals that confirm the session is doing its full work.

Infrared sauna is the stronger choice for recovery, chronic pain management, and metabolic support. Begin with three sessions per week and build toward daily use as the body adapts to the longer duration and deeper tissue engagement. The lower thermal demand makes consistent daily infrared practice sustainable for most people, and the cumulative mitochondrial and metabolic benefits compound meaningfully over months of regular practice. Athletes using infrared for recovery will find improvements in muscle soreness resolution, sleep depth, and readiness between training sessions — benefits that emerge from the cellular depth that ambient heat alone cannot reach.

Both protocols demand attention to hydration, and the longer duration of infrared sessions makes electrolyte management especially important. Sweating at lower intensity over 40 to 45 minutes depletes sodium, magnesium, and potassium without the acute urgency of a shorter, hotter session — making it easy to underestimate the cumulative loss. Hydrate before entering, not only after. Include electrolytes in that intake, not only water. Dehydration inside the sauna — reduced plasma volume, impaired cardiovascular response, diminished sweating capacity — undermines the very adaptations the practice is designed to produce.

Several contraindications apply across both formats. Uncontrolled blood pressure carries real risk, given the significant cardiovascular response either protocol generates; anyone managing hypertension should proceed with caution and consult a physician before starting. Pregnancy warrants careful consideration, particularly in the first trimester, when elevated core temperature carries documented risk. Active infection places additional demand on an immune system already under pressure, making either format inadvisable until recovery is complete. For heat-sensitive individuals or anyone building a practice from scratch, infrared is the gentler, safer entry point — the Finnish sauna's extraordinary benefits are best reached by starting where the body is, not where ambition leads.

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