As you already know from Part I of this series, saunas are the Hot Secret to Building Muscle. Check out that blog post to see how heat stress on the body through sauna use can help you maintain your current muscle mass AND help you build more muscle mass. Sauna use is great not only for building muscle though--it’ll help you last longer in your workouts too. Less energy devoted to pumping blood and more energy devoted to pumping iron.
Exercise raises core body temperature causing acute stress. If you’re acclimated to the heat, you can decrease the impact of this acute stress, thereby increasing your resilience and endurance. Pretty dope, I know.
So what exactly do we mean by “last longer”? We mean feel fatigue later in a workout. You’ll be running like a fine-tuned race car: powerful by default, and efficient by adaptation. Heat acclimation increases and optimizes blood flow to the big exercise and endurance engines in your body: your heart, your muscles, and your cooling system.
But how does it do this? Well, many times the reason why something occurs may be more important than the fact that it occurs at all (see here for more on this concept). To get a better idea of the why, let’s explore the mechanisms people...
Both blood plasma volume AND blood flow are increased during acute hormetic heat stress and afterward as an adaptive response . Because there is a greater volume of blood AND it’s flowing quicker, you can last longer during your exercise routine. It’s like not only having a bigger engine in your car, but more fuel in it also!
Your heart won’t have to work as hard, which, like we said, means less energy devoted to pumping blood and more energy devoted to pumping iron. This has been shown to be effective in people who are just starting out their fitness journey and people who already have a solid base of fitness too(1).
Muscle glycogen (the go-to fuel for highly intense movements) is spared once you become heat adapted, meaning you won’t be using as much stored energy to accomplish the same work (2,3). This means you have the ability to go longer and harder than you could before, just by routinely spending a few minutes in the sauna and getting some heat acclimation.
But one question is, if you’re doing a high-intensity workout and you’re not using as much muscle glycogen for fuel, then what are you using for fuel? Well, it’s posited that increased blood flow may provide circulating blood glucose and fatty acids as fuel and, in turn, more quickly expel lactic acid. It’s like having a hybrid race car that can switch over to electric power to spare some of its traditional high powered fuel.
THE COOLING SYSTEM
Sauna usage and heat acclimation will help keep you cool. This might seem counterintuitive but let’s dive deeper. The more you exercise (which elevates your core body temperature) or the more frequently you are exposed to heat (which also elevates your core body temperature), the more efficient your body gets at cooling you down. It forces adaptations to this somewhat infrequent but acute stress. In order to cool itself, your body increases blood flow to the skin and thereby begins to sweat. And the cool thing is (pun intended!) that once you’re heat adapted, you’ll sweat at a lower core body temperature during exercise and sweat for a longer period also. You will inherently be able to last longer and perform better (4). It’s like the coolant system in a race car working quicker and more effectively, staving off the machine from overheating and allowing it to go longer!
Best of all (*drumroll please*) sauna use will improve your performance and endurance in both strength training and “cardio” workouts like sprinting. It’s all symbiotic people: increase your endurance, which will increase your anaerobic capacity, which will increase your aerobic capacity! (Check out the previous blog post on the interplay between strength training and “cardio”.)
These are all extremely compelling arguments and evidences for sauna usage, especially because it requires very little effort (you’re literally just sitting there) for very little time (10 or 20 minutes.) Bring the heat if you’re ready to last longer and run like the fine-tuned machine you were meant to be. Give it a shot and hit us up in the comments!
In Excellent Health,
Garrett & Luc