Recently just like cold water immersion the sauna has become a big trend.
Do you know why you’d use it?
Are you doing it right?
What is it doing to the body?
Core temperature increase
As you sit there in the dry heat the body temperature rises as this happens there is a need for cooling.
One of the primary functions of the cardiovascular system is to cool the body to maintain safe functioning levels. So what begins to happen is that the central governor sends blood just under the skin's surface, and you begin to sweat. This is the evaporation cooling process. Sweating.
This evaporation process reduces blood volume via blood plasma volume. The heart has less blood volume to pump around the body and you begin to see it work harder. Your heart rate increases without doing any work just sitting there.
Here is a graph of my heart rate in the sauna lying completely horizontal with very little movement this is called cardiac drift. Effort level has not changed yet HR is increasing.
That final spike was me just getting up and walking out of the sauna just for context. Then I had a 90sec cold shower and sat pool side for 3:30min
Recap of what is happening
Heat Stress and Vasodilation:
The high temperature causes blood vessels near the skin to dilate (vasodilation) to help dissipate heat through the evaporation process, sweat.
This increases blood flow to the skin, reducing the blood volume available for the heart to pump to other body parts.
Decreased Blood Volume:
Sweating in the sauna causes fluid loss, which reduces plasma volume.
Lower plasma volume = less blood volume and means the heart has to work harder to pump sufficient blood, resulting in an increased heart rate to maintain the cooling process. That cycle continues until it can't.
Cardiovascular Drift:
Over time, the combination of fluid loss, reduced stroke volume (amount of blood pumped per beat), and the continual cooling process causes cardiac drift, where the heart rate rises even if you are at rest in the sauna.
Using a sauna for heat training has amazing benefits on performance especially for endurance athletes preparing for a race in the heat or someone like a firefighter. Because if your HR is rising in the heat with little movement imagine what it is doing when the heart now also needs to send blood to working muscles or your brain to make better decisions.
The heat alone has you starting at a higher % of your capacity.
Why use the Sauna
Regulating the blood flow and plasma volume, reducing cardiac drift during activities.
Increased efficiency in sweat production and improved cooling mechanisms reduce the overall strain of heat on the body.
Sauna exposure stimulates the production of plasma (the liquid portion of blood). Offsetting fluid losses and improves stroke volume (amount of blood pumped per heartbeat).
Enhanced plasma volume translates to better cardiac efficiency, even in non-heat conditions.
Heat shock protein release to support the repair of oxidative stress and damaged proteins
Long term exposure can increase red blood cells meaning more oxygen carrying capacity
There are some things to consider:
Sauna usage for heat training is very controllable because it is passive. This means if done right it won't take anything away from training like working out (run or cycle) in a heat suit for example.
It must not take away benefits or increase fatigue for your actual training
Hydration is important pre and post sauna usage
You have to remember this is STRESS and the body requires rest to adapt
Build tolerance over time
Do you use the sauna what benefits have you noticed?
Are you using it for performance gains?
If you arent would you like a heat training protocol?
Thanks for reading please share with a friend if this helped.
Comment below ⬇️
DG 🤙🏼
コメント