Have you ever heard claims such as ‘a single sauna session mimics moderate exercise’, or ‘taking a sauna is the same thing as going for a half hour long jog.’ Statements such as these are made by sauna companies and health influencers across the internet as well as in vivo interactions. So, what is really happening in a sauna to cause the rumor mill to start turning? Is it a myth that saunas mimic exercise, or is there some truth behind this over-stated claim?
The reality is that this claim has some basis in science based evidence, but it is not the whole truth. There are some aspects of certain types of saunas sessions that will give the body a similar aerobic effect as a moderate cardiovascular based workout. The reality is that there are many different types of exercise and under certain conditions the use of a sauna as a substitute for exercise is an excellent option.
Is taking the sauna equivalent to weight bearing exercise or hitting the gym to lift weights? Absolutely not. However, the biomechanics of a sauna can improve blood flow to muscles that were trained during a workout and ultimately this will aid recovery so that more workouts can be performed during a weekly time frame.
Saunas do support cardiovascular health and can sometimes be substituted for cardiovascular workouts, or can be used to enhance other workout experiences to improve recovery rates. You will not build more muscle by sitting in a sauna alone, nor will you activate certain skill sets to perform at a higher level in different sports. So, the answer to the question about whether claims that saunas can replace exercise is more nuanced than a simple yes or no. In fact, the truth is that saunas can improve cardiovascular function, but cannot replace exercise entirely.
The exciting aspect about saunas as a potential tool for aerobic exercise is how this evidence can support certain populations who are immobile, recovering from injury, or adapting to exercise from a previously sedentary lifestyle. There is strong evidence that sauna use can replace aerobic exercise and this fact may be a game changer for those who would otherwise be stuck on the sidelines.
Find out the details of the new study that unequivocally demonstrates sauna use as not only equal to an aerobic workout, but possibly more effective than a session on a stationary bicycle at near maximum capacity.
The Evidence and Data — The Details of the Groundbreaking Study that Found Saunas to be Equivalent to Moderate Aerobic Exercise
At its foundation the claim that saunas are a comparable form of aerobic exercise to actual physical cardiovascular workouts is a study that was published in 2021. This study found that saunas alone stimulated the cardiovascular system in a comparable way to the same amount of time spent exercising plus some time in a sauna. (1) The positive and wide sweeping result from this study shows that those who are in need of aerobic exercise, but who are, for whatever reason, unable to exercise can still positively stimulate the cardiovascular system in a sauna alone.
Published by the National Library of Medicine the paper entitled ‘‘Standalone sauna vs exercise followed by sauna on cardiovascular function in non‐naïve sauna users: A comparison of acute effects’ (1) sought to find out, if in fact, a sauna session was equivalent to moderate aerobic exercise. The authors claim this as their purpose in conducting this study.
“Therefore, the purpose of the study was to explore the hemodynamic changes of a single session of sauna exposure compared to the combination of aerobic exercise and sauna exposure of matched duration, in a population with at least one cardiovascular risk factor.” (1)
The study examined 72 participants who all had at least one risk factor for developing a cardiovascular disease. The subjects were placed into two separate groups to compare the effects of a single sauna session versus exercise coupled with a sauna session.
The first group took a 30 minute sauna session with the temperature set to 167 degrees Fahrenheit. A traditional Finnish sauna was used for this experiment. The second group spent 15 minutes cycling on a stationary bicycle at 75% of their maximum heart rate and directly followed this with a 15 minute sauna session. A variety of biomarkers were measured before and after both sessions, including blood pressure, heart rate, arterial stiffness, and arterial pressure. (1)
This is a graph depicting how the groups were organised:
(1)
Surprisingly, the results did not demonstrate any significant cardiovascular differences between the two groups. This shows that the 15 minutes spent at 75% of maximum heart rate on a stationary bike was equivalent to sitting in a sauna for 15 minutes for aerobic effect on the body. These findings are highly significant for anyone unable to exercise, but still needing to stimulate their cardiovascular system.
For example, this means that someone recovering from injury could still engage their cardiovascular system in a sauna without any impact activity. Anyone who is chronically unable to move their body in such a way that they could activate their cardiovascular system has the option to enter a sauna and still benefit from aerobic stimulation. This study shows that saunas reduce blood pressure, and arterial inflammation without requiring the movement of the body.
Sauna only participants demonstrated a greater change in critical cardiovascular biomarkers than the group that exercised and used a sauna.
“Our results showed that SAUNA induced greater changes PRE‐POST compared to EX+SAUNA in both DBP and MAP.” (1)
*** EX+SAUNA = Exercise + Sauna
The authors describe the groundbreaking evidence for individuals unable to move their bodies, but still in need of aerobic exercise when they write.
““From an acute standpoint, sauna bathing is able to elicit responses that are comparable to a combination of aerobic exercise followed by the sauna, when matched for duration. For populations who are unable to perform aerobic exercise, sauna exposure may provide some similar benefits acutely.” (1)
The authors continue to elaborate on the fact that saunas are a reasonable alternative to exercise for those individuals in need when they state this.
“The sauna is a suitable option for acute blood pressure reductions in those who are unable to perform aerobic exercise, and may be a viable lifestyle treatment option to improve blood pressure control.” (1)
This study only examined the effects that saunas have on the activation of the cardiovascular system. It should be noted that sitting in a sauna will not replace activation of the muscles of the body.
Just knowing that saunas can operate as a stand-in for aerobic exercise is very exciting, but why is it that exposure to heat can activate the cardiovascular system in a similar way to fairly aggressive aerobic output on a stationary bicycle?
Find Out the Biomechanics Behind Saunas and Cardiovascular Engagement
When most people think of a sauna they consider how deeply relaxing it can be to sit down, or even lay down in a sauna and let their cares melt away with the heat. So how is this activity considered a strenuous aerobic activity?
The reason why saunas can activate the cardiovascular system in a way that mimics exercise for the heart is because of the heat stress placed on the body, and the thermoregulation that ultimately ensues from this.
Unlike any other species on earth, humans have the very unique ability to regulate their internal temperature through the process of perspiration. In order to reach the point where sweating begins, the cardiovascular system must engage to begin the process of cooling the body down in order to protect the brain, and as well as other internal organs. Essentially, humans have a built-in air conditioning system that requires a huge amount of energy and engagement from the cardiovascular system.
According to the previously mentioned study, the authors describe the mechanism of cardiovascular engagement from a sauna session when they write.
“Sauna bathing exerts a strain on the cardiovascular system, to maintain blood pressure and sufficient blood flow to other organs and muscles.” (1,4)
As heat stress is applied in a safe manner in the sauna the body naturally begins to cool itself off through sweat and eventual evaporation. The process begins in the brain known as the hypothalamus, a paper published by the National Library of Medicine entitled ‘Physiology, Temperature Regulation’ (5) describes the first signals that the body is overheating when the authors write this.
“The human body’s thermostat is the hypothalamic thermoregulatory center, which, more specifically, is located in the preoptic area of the hypothalamus. This center sets the body’s set point and regulates temperature homeostasis. The hypothalamus contains temperature sensors, which receive information via nerve cells called thermoreceptors.” (5)
Once the brain receives the signal from the central nervous system to begin cooling the body off, a cascade of biochemical changes occur including the enlistment of the cardiovascular engine. As blood begins to move through the upper chambers of the heart and back through the lower chambers of the heart this induces increased circulation throughout the entire body, and also reduces inflammation of the arteries.
The body needs to draw blood away from the surface of the skin and back around the organs to protect them from the threat of the extreme heat in a sauna. The catch is that a sauna session only lasts for 20-30 minutes, so the threat is not real, but still places hormetic stress (healthy stress) on the body for just long enough to reap the medicinal benefits.
The required exertion from the entire cardiovascular system in order to cool the body off during a sauna session is enormous. So great is the demand on the cardiovascular system that the results after a single sauna session on the heart and surrounding arteries is greater than if the individual had been cycling at 75% of their maximum heart rate. (1)
While saunas can be used to exercise the cardiovascular system for many reasons in different populations, it cannot increase muscle development directly. Find out how saunas can indirectly help with muscle development by allowing faster recovery times between sauna sessions.
How Can Saunas Improve Muscular Recovery So That You Can Get Back to the Gym Faster
Saunas directly engage the cardiovascular system, however they do not directly improve muscle development and are not entirely a substitute for exercise. Saunas can help with muscle recovery in general by supplying more oxygen and healthy nutrients to the strained muscles through improved circulation. (6)
If you are already involved with a muscle development protocol in the gym or anywhere else, the real work happens when muscles begin to repair themselves from the damage caused during lifting. Any activity to improve this recovery process will inevitably help in the building of muscles.
The heat of a sauna induces extreme improvements in circulation. As circulation is improved oxygen, proteins via heat shock proteins are delivered to muscles in a more efficient and healthier way. When this occurs the damage done to the muscles during a workout begins to be repaired. As recovery time is improved it is likely that individuals will be able to go back to the gym sooner then if they had not taken a sauna.
So, while saunas are not able to directly improve muscle tone and development, they can aid in the recovery process and therefore indirectly help to improve muscular development.
Saunas are not a complete replacement for all kinds of exercise, but taking a sauna regularly will improve all kinds of exercise.
When, Who, and How to Use a Sauna as a Substitute for Exercise
- Cardiovascular Risk Factors
- High Blood Pressure
- During the Down Time of Injuries
- Preparing to Exercise
- A Replacement Aerobic Workout for the Over Trained Athlete
- Individuals Who are Immobilized and Unable to Exercise for Any Reason
Saunas cannot entirely replace exercise all of the time, but there is a time and a place when they can be used as an excellent alternative to exercise. This is especially true for any individual living with cardiovascular risk factors such as hypertension, clogged arteries, or chronic heart failure. Sitting in a sauna is a way to quickly reduce blood pressure and ease any stress on the heart, including inflammation of the arteries. A sauna is a safe and efficient way to address many cardiovascular risk factors, and especially for anyone for whom exercise is prohibitive.
Populations that still require aerobic exercise but are unable to do so physically can turn to a sauna to improve their cardiovascular health. For example, an athlete who has been injured can maintain aerobic fitness during the healing process. Instead of being back to square one, some level of engagement can continue until the individual can go back to the track, court, or field.
For anyone who has previously experienced a sedentary lifestyle could use a sauna to begin to prepare them for the eventuality of physical exercise. According to the paper entitled ‘Standalone sauna vs exercise followed by sauna on cardiovascular function in non‐naïve sauna users: A comparison of acute effects’ (1) a series of sauna sessions to build up exercise tolerance could be useful for individuals who have been leading a sedentary lifestyle.
“Long‐term sauna therapy has been shown to effectively improve exercise tolerance, while regular exercise and sauna exposure were able to improve cardiac function and autonomic nervous system activity.” (1,6)
Some athletes are overtrained, especially for highly demanding sports such as endurance athletes, soccer players, or boxers/fighters. These athletes would do well to save the strain on joints by replacing one or two aerobic sessions per week with a sauna. For example, skip the 30 minute jog that you may take in the morning before the main workout in the afternoon and replace it with a sauna session. Endurance athletes can turn to sauna sessions as an injury prevention method.
Finally, anyone who is, for example, wheelchair bound, or is unable to engage in aerobic exercise for extended periods of time may find a safe haven in using a sauna as an alternative to aerobic exercise. It is truly for this segment of the population that saunas can become a magical platform to still engage the cardiovascular system. It is for this demographic that saunas can be used as a replacement for exercise, and the scientific data is evidence of this possibility. In concluding remarks from the study that was examined previously the authors write.
“This study demonstrated that when matched for duration, EX+SAUNA and SAUNA elicit comparable acute hemodynamic alterations in middle‐aged participants with cardiovascular risk factors. The sauna is a suitable option for acute blood pressure reductions in those who are unable to perform aerobic exercise, and may be a viable lifestyle treatment option to improve blood pressure control.” (1)
(Ex+Sauna = Exercise + Sauna)
Saunas cannot be said to be an exact mimicry of all types of exercise, but they do mimic aerobic exercise and can be used as an alternative as it is appropriate for individual cases. Saunas are not a replacement for weight lifting though they can help during the recovery phase.
If you do have cardiovascular health concerns and are unsure if sauna use is safe for you, then please consult your medical physician. All sauna users must be conscientious of maintaining excellent levels of hydration throughout the day every day. Please be sure to include electrolytes as well as plenty of essential minerals.
Go forth and enjoy the sauna knowing that yes, saunas can replace aerobic exercise as needed!
Sources Cited:
- https://pmc.ncbi.nlm.nih.gov/articles/PMC8485612/
- https://pmc.ncbi.nlm.nih.gov/articles/PMC8202594/
- https://pubmed.ncbi.nlm.nih.gov/31126559/
- https://pubmed.ncbi.nlm.nih.gov/12744548/
- https://www.ncbi.nlm.nih.gov/books/NBK507838/
- https://pubmed.ncbi.nlm.nih.gov/30077204/
- https://pubmed.ncbi.nlm.nih.gov/21944673/