Physiological Adaptations That Occur When You Exercise In The Heat

A bizarre time to write about training in the heat while in the middle of January. 

I had to write this for school so it is what it is. Just as it is 5 o'clock somewhere, it is also hot somewhere.

But regardless, it will get warm again and there are many considerations to think about during the process of acclimatization to hotter weather.

When an athlete trains in the heat for two weeks, a variety of physiological changes occur. 

During the first week of training in the heat, the athlete will experience changes that lower the heart rate, core temperature, and skin temperature, while resting and performing exercise at less than maximal output. 

As time goes on, the athlete’s blood pressure will become more stabilized during periods of extended exercise. 

The athlete’s threshold temperature to begin sweating will lower and sweat will become better distributed over the surface mass of the skin. 

The acclimatization process will also increase peripheral conductance, plasma volume and overall sweating capacity. 

Blood flow to the skin will decrease with time, which will allow central blood volume to be restored to more optimal levels. 

Stroke volume and muscle blood flow will benefit from better blood volume during exercise. As the blood flow to the skin decreases, the sweating and evaporative cooling capacity of the athlete will increase. 

The process of heat conductance will improve, as training time continues. This will also assist in the lowering of the athlete’s core temperature. 

The acclimatization process will also produce an increased blood plasma volume, as more water will be drawn into the plasma. The increases in plasma volume can be as much as 12%. 

The amount of sodium chloride that is lost through sweat will decrease, as more aldosterone is secreted, to maintain a better salt and water balance. 

This acclimatization process can only be optimized through the combination of the athlete training, while exposed to the heat.

So as you can see, there are a lot of physiological changes going on during your first two weeks of training in the heat. 

Plan for that and take the necessary precautions such as good nutrition, adequate hydration, proper clothing etc.. and you will be breaking records in no time, when the sun is blazing!

Until then, bundle up, dress in layers, eat good, stay hydrated and allow extra time for warm-ups in the cold. 

Train hard and stay safe!

References:

Fahey, Thomas. Strength and Conditioning, 3rd Ed. Carpinteria: International Sports Sciences Association, 2013. Print

Eric Dempsey

MS, NASE Level 2 Certified Speed Specialist

Dempseys Resolution Fitness