Sauna for Runners: How Heat Therapy Can Improve Recovery and Endurance

Unless you were born and raised in Finland, chances are saunas aren’t part of your daily routine. You’ve seen them, maybe tried them, and decided that frequent heat therapy might not be for you. But it’s time to change that. If you’re practicing endurance sports like running, you’re missing out on several benefits that could boost your performance.

Historically, saunas have been used for relaxation and hygiene. Yet, in recent years, they’ve found fame among runners, cyclists, and other physically active people due to different sauna-induced physiological responses, like improved cardiovascular efficiency, heat acclimation, and even muscle growth.

If you’re looking for that extra something that could give you an edge, sauna therapy could be it. So, let’s explore the science behind the sauna for runners and how it can help you reach your peak potential.

How saunas can benefit you as a runner

There’s often a love-hate relationship when it comes to saunas. Some people enjoy the hot air, sweating, and getting red cheeks that come with it, while others claim heat worsens their well-being and prefer to stay cool. 

I used to be one of those sauna avoiders, but the truth is that the more you get exposed to heat, the better you feel in hot and humid conditions. That’s often the case of summer running. But not only that. Regular sauna use can also lead to such beneficial adaptations as faster recovery, improved muscle hypertrophy, and increased cardiovascular efficiency. 

Let’s unpack each one of these benefits.

Faster recovery

If there’s one thing all runners long for, it’s to feel well and fresh after every run. But if you’ve run a record-long workout or had an intense track session, muscle soreness is inevitable. Or is it?

Post-workout heat therapy, like sauna bathing, dilates blood vessels, promoting blood flow to fatigued muscles. This process aids in the removal of metabolic waste products like hydrogen ions, which accumulate during intense exercise and contribute to inflammation and muscle soreness the next day. In fact, heat therapy is proven to be even more effective at the job than cold treatment.

However, in contrast to popular belief, the main cause of post-workout pain isn’t lactic acid but tiny tears in your muscle fibers. You can’t avoid it entirely after a particularly hard workout. 

Yet, taking a sauna after exercise can accelerate the repair process as increased circulation delivers oxygen and nutrients essential for repairing the damaged muscle fibers. That’s good news if you have two workouts a day or need to recover quickly after a race. 

Sauna use also promotes relaxation due to the post-session activation of the parasympathetic nervous system, which is important in improving sleep quality. And sleep, as we know, is the prime time for protein synthesis and muscle repair.

Improved muscle growth

Muscle growth is key to improving strength and sustaining more intense workloads. Any workout that’s been hard enough for your body will result in tiny muscle tears – a signal to the brain to create additional muscle fibers so that the muscle is better equipped to endure a similar effort next time.

Regular sauna use is known to contribute to muscle hypertrophy. Heat stress activates the mTOR pathway, which is directly related to protein synthesis. It also increases blood flow, ensuring that muscles receive a steady supply of nutrients and hormones necessary for growth. Furthermore, heat exposure stimulates the production of heat shock proteins, which help transport repair proteins and remove toxic metabolites. 

Now, many endurance athletes get hesitant when they hear the words “muscle hypertrophy”, fearing becoming bulky. But remember—muscle growth is essential to becoming stronger and delaying fatigue in long runs. Plus, sauna sessions can only promote the physiological adaptations already induced by the exercise, and cardio workouts don’t result in exponential muscle-building.

Overall, direct studies on sauna-induced muscle growth in runners are still limited, yet the general enhancement of recovery and reduction in muscle soreness can create a more favorable environment for consistent training and muscle development.​

Enhanced endurance

One of the most compelling benefits of sauna use for runners is the potential improvement in endurance. Repeated heat stress has been known to stimulate the production of more red blood cells, which eventually increases the total blood volume and helps deliver more oxygen to the muscles. This, in turn, also induces the creation of mitochondria—energy powerhouses inside muscle cells.

More oxygen means more energy and a higher VO2 max – a measure most often linked to a better aerobic capacity and enhanced running performance. A study with 20 middle-distance runners concluded that weekly 30-minute sauna sessions can substantially improve VO2 max and time to exhaustion in hot conditions in just 3 weeks.

This can be a particularly interesting benefit for runners and endurance athletes who are gearing up for a race in hot temperatures or simply would like to feel better while exercising in summertime. Spring is the perfect time to improve your heat tolerance, and a couple of sauna sessions a week will do it. Plus, the adaptations gained will boost your efficiency while running in mild temperatures as well.

Finally, exposure to heat leads to more than just the physiological benefits. Sitting in a sauna requires discipline and adaptation to discomfort, similar to endurance training. This mental resilience can help you improve focus and pain tolerance during long-distance running workouts and races.

Practical guidelines for sauna therapy

If you’re new to sauna use, taking a 1-hour session right away is not just unadvisable; it can actually be detrimental to your health. As with any new practice, it takes time and several steps to get used to it. 

So, consider the following guidelines to safely and effectively incorporate sauna sessions into your running training routine:

1. Timing: Use the sauna after your workouts to aid in recovery. Post-exercise sauna sessions can enhance blood flow to muscles and accelerate healing.​ However, skip sauna if you feel extra tired and may fall asleep during the session.

   
   

2. Duration and frequency: Begin with shorter sessions of 5-10 minutes and gradually increase to 20-30 minutes as your tolerance improves. Aim for 3 sessions per week to maximize benefits.​

   
   

3. Hydration: Ensure you are well-hydrated before entering the sauna and rehydrate adequately afterward to compensate for fluid loss through sweating.​ Drink at least a glass of water before and after sessions.

   
   

4. Temperature: Traditional saunas typically operate between 70°C to 100°C (160°F to 210°F). Start at lower temperatures and move to a hotter sauna as you become more accustomed to the heat.​

   
   

5. Type of sauna: Saunas vary in terms of humidity. Typical Finnish saunas are dry, while steam saunas, like the Turkish ones, have 100% humidity, which can be particularly beneficial for people with respiratory conditions or dry skin.

6. Cool down: Allow your body to adjust after exiting the sauna by cooling down gradually. A cold plunge straight after heat therapy may not be for everyone; however, it can intensify some of the physiological benefits of sauna.

7. Listen to your body: Pay attention to how you feel during and after sauna sessions. If you experience dizziness, nausea, drowsiness, or discomfort, exit the sauna immediately and cool down.​

   
   

8. Consult a professional: Before beginning any new therapy, especially if you have underlying health conditions like low blood pressure or heart disease, consult with a healthcare provider to ensure sauna use is appropriate for you.

   
   

Final verdict: Is sauna for runners worth it?

Integrating sauna therapy into your running routine can offer numerous benefits, from faster recovery to enhanced muscle growth and cardiovascular endurance. It can be a true game-changer, providing a natural, passive way to improve your running performance.

Start with one or two short sessions over the weekend to ease yourself into the heat therapy. Follow the practical guidelines and, most importantly, notice how your body reacts as you increase the duration. Adding sauna to your running regimen will help you feel more resilient and achieve greater results as a runner.