Why is it important to track core body temperature?
The effects of core body temperature on physical performance have been under research for a long time. As a result, we have a pretty good idea of how the body reacts to heat while doing sport, especially in terms of cardiac output and energy creation. In this blog post, we will cover the most relevant insights coming from this research, as well as some of the direct consequences in terms of athletic performance.
First of all, we need to start with the basics: the human body needs a stable temperature to stay healthy. The core body temperature fluctuates, and the body needs to react accordingly. That means that it is continuously expending energy to maintain its stability, either creating more heat under cold conditions or dissipating heat when the environment is hot. However, the process is not straightforward, nor exact.
What does this fact mean to athletic performance? There is plenty of scientific research about this topic, so we will just quote some relevant papers to make our point. First of all, the body needs to divert cardiac output under hot conditions to dissipate heat through the skin. As explained by Périard and Racinais (Périard and Racinais, 2019: page 5): “While resting in a thermoneutral environment, about 0.5 L/min of blood (5–10% of cardiac output) is supplying the cutaneous circulation, but during heat stress the cutaneous circulation receives up to 8 L/min (50–70% of cardiac output)”. That means that if we are under heat stress most of our energy will go to try to compensate for the core body temperature. Obviously, that will affect sports performance! In fact, aerobic exercise performed in the heat is impaired compared to cool conditions.
However, it is possible to use several strategies to minimize this impairment, as explained by Périard:
- Aerobic fitness.
- Heat acclimatization.
- Hydration. Gradual dehydration has been shown to exacerbate the rise in thermal and cardiovascular strain during heat-stress exercise in proportion to the extent of body water loss.
- Cooling during the event.
How could these scientific facts help us to improve our training and overall physical status? Controlling our core body temperature fluctuations might be useful to prevent in advance heat stress situations where our performance could be seriously undermined. That is what CORE is about! By getting core body temperature tracking to everybody we want to help athletes to better understand their bodies, improving training and getting better results.
(1) Périard, Julien D., Racinais, Sebastien (Eds.) (2019): Heat Stress in Sport and Exercise, Thermophysiology of Health and Performance, Springer.