Hot, Hot Summer

How to keep competing as temperatures soar.
By Sam Van de Velde, Lone Peak Performance Exercise Physiologist

This summer has been a doozy. We’ve already experienced dozens of 90+ degree days and we’re still in July. How can we keep training and riding into the alpine when the heat makes us want to crumble? Can short-term use of heat stress during training improve endurance performance and performance in the heat by providing a means of heat acclimation prior to competition? 

Short answer: absolutely!

Heat acclimation can be achieved in a quick four-day stint of intentionally exercising in the heat at 65-75% of your maximum effort (see template below). In terms of how hard this intensity is, your Rate of Perceived exertion on a scale 1-10 should feel about a 4-6 disregarding the discomfort of heat.

Staying hydrated and well fed is also critical to the process of temperature acclimation, and it’s important to note that it’s ineffective and dangerous to intentionally restrict liquid intake in an attempt to teach the body to perform well without it. You’re better off supporting your body’s natural adaptations with plenty of fluids.

What is Heat Acclimation?
Heat acclimation or acclimatization plays a large part in the body’s physical responses and overall ability to cope with heat exposure. Heat acclimation is a broad term that can be loosely defined as a complex series of changes or adaptations that occur in response to heat stress in a controlled environment over the course of four to 14 days. These adaptations are beneficial to exercise in the heat and allow the body to better cope with heat stress. Heat acclimatization describes the same process, but happens in a natural environment. In either case, the positive adaptations that occur include reductions in:

• Heart rate

• Internal body temperature responses

• Skin temperature responses

• Sweat electrolyte concentrations

• Rating of perceived exertion

And increases in:

• Sweat rate, which helps dissipate heat and improve your cooling system

• Conserved salt and electrolytes

• Sweat onset (sweating starts earlier)

• Cardiac Output (Blood flow increases improve endurance performance in the heat.)

• Exercise performance in the heat and even in cooler conditions

A Record Hot Summer Upon Us
Montana is experiencing drought and we’re on our way to setting records for days above 90 degrees. As an endurance coach, this phenomenon builds two key concepts into my summer training plans. 

1.     Heat acclimation prior and heat stress during competition
2.     Potential of fire and poor air quality during crucial training blocks

Methods of Inducing Heat Stress
So, how do we safely induce heat stress and continue training? There are several ways:

1.     Cycling indoors/outdoors for 30 min @ 65-75% of max without moisture-wicking clothing
2.     Sauna use 10-15 min post exercise
3.     Although less effective, practice short- and mid-endurance rides in the heat of the day. (The convection of riding outdoors isn’t guaranteed to give enough of a consistent stimulus to body core temperature to absolutely ensure acclimation.) 

Always, always, always hydrate, and be sure to use an electrolyte substance—I prefer NUUN. Heat Training can be dangerous and unhealthy if not done properly, however the benefits can prevent heat stroke as summer wears on. Consult svandevelde@lonepeakpt.com to learn more. Training in a spring-style wetsuit for 30 mins indoors or 30-50 minutes outdoors is another effective method.

4-Week Heat Acclimation Schedule Prior to Competition