Your Fitness Guide for Summer: How to train in the heat

by Emily Caine

Every year as summer approaches there is a keen interest and renewed enthusiasm for all things sport and fitness. For many of us that naturally involves a greater time spent outdoors and as we enter the warmer months, we need to consider how the heat and humidity will affect our ability to exercise. So, how can we train in the heat, still hit those goals and keep ourselves safe? Here are four key aspects to consider before planning your next summer sweat session.

Managing Body Temperature

Before we look at how to manage our body temperature, we need understand how it cools. In order to maintain a stable body temperature, around 37C, a balance between heat gained and heat lost needs to be achieved. As our temperature rises the body has to make a decision between keeping blood pumping to our muscles for performance or sending that blood to the skin to cool down. The latter is always prioritised as it is required for survival.

Our bodies maintain our body temperature in four ways, radiation, evaporation, convection and conduction.

During exercise, our body uses mainly radiation (dispelling heat from our skin into the environment) and evaporation (sweat) to stay cool. But how can we manage this when the heat feels like it’s working against us and our body can’t keep up? Pre-cooling is one way!

Pre-Cooling

Pre-cooling is used to lower the core body temperature and should be used right before your workout. Here are some ways to cool yourself down before exercising:

  • Ice baths or cold shower for a few minutes
  • Place a wet towel or ice pack on your neck, armpits or groin
  • Have a Slushie or ice drink (freeze your Powerade or Gatorade!)

Keep in mind that one of the best ways to avoid exercise induced heat illness and decreased performance is to avoid workouts at the hottest part of the day!

Hydration

During a hard workout in moderate heat it is common for us to lose between 1- 2 litres of water through sweat and breathing. When this water is not replaced it results in dehydration which severely limits performance and greatly increases the risk of heat exhaustion. Sports Medicine Australia recommends that hydration should be focused on before, during and after competition or training.

Tips to stay hydrated

  • Start by drinking 500ml of water 2 hours before exercise
  • If exercise lasts longer than an hour, drink 500-700ml of water or a sports drink throughout
  • Continue drinking water following exercise until you feel rehydrated.

Most importantly, make sure you are aware of the common symptoms of dehydration.

Acclimatisation

Acclimatisation is the process by which we build a tolerance to exercising in the heat. Acclimation is important for protecting performance and a significant factor in reducing the likelihood of heat related illness during exercise.

Research has been conducted on acclimatisation in many different fields and we know that in general it takes a person roughly 7-14 days of exposure to heat where at least 90 minutes of moderate exercise is being performed. At 14 days the resting core body temperature of a person will have decreased by around 0.5 C. Acclimatisation also involves cardiovascular and metabolic adaptions which further improve a person’s response to training in the heat.

Tips for acclimatising

  • Don’t start with anything too strenuous, a walk is a great place start!
  • Ensure you take breaks as you need and stay hydrated
  • Stick with exercise that you are familiar with for the first few weeks
  • Wear loose fitting clothing that will protect you from the sun but allow your skin to breathe

Fitness

People with higher levels of fitness are more able to deal with the heat stress while exercising. High levels of fitness are usually associated with lower core temperature and a faster response in sending blood to the skin surface for cooling. Excess body fat makes the regulation of body temperature slightly more difficult even at rest. These aspects of fitness are often gained over a long period of time, all the more reason to keep setting those fitness goals!

Over motivation

Increased fitness levels are sometimes associated with greater risk of over motivation. The level of fitness where an individual is used to the discomfort of training and has previously ‘pushed’ themselves to achieve goals. This can lead to sense that the same discomfort applies with heat stress. Quite often this is seen in competition and the consequences can be life threatening.

It is important to consider that if you are going for a personal best in a workout or competition, paying attention to the environmental conditions is always a wise decision.

Always remember to take into account your own health and physical fitness levels before exercising in the heat. Heat related illnesses can be life threatening and require immediate attention. Read here for more information the signs and symptoms to look out for.