Training in the Heat

Welcome Summer!

Living in Texas is fantastic for so many reasons! First off, we have tasty food and can train outside year-round. A downside to Texas is our summer heat and humidity. This coming week, we are going to reach 100+ degrees F every day. As athletes, we need to be aware of how nutrition and hydration should change in this type of weather. Learning about thermoregulation, tips on how to train in the heat and nutritional alterations to consider are topics discussed in this blog.

What is thermoregulation?

Thermoregulation is the body’s cooling system that maintains our internal temperature within an ideal range. As your body temperature rises, the blood is diverted from the muscles and gastrointestinal system (GI) to the skin, to aid in cooling the body. When there is less blood flow and oxygen going to the muscles and GI system, their ability to perform decreases.

As heat increases, the likelihood of GI complications

increases and muscle performance decreases.

FUN FACT: About 80% of the energy produced by working muscles is heat”. This heat must be regulated and dissipated by the body. When training in hot summer months, athletes tend to struggle when the heat generated is more than what can be offloaded. The body initiates a cooling response in the form of sweating and re-directing the blood flow towards our skin. High humidity can impact performance significantly due to an increased difficulty in dissipating heat.

So, what can we do?

Here are a few tips on how to navigate training in the summer heat.

• Heat Train – This causes physiological adaptations that increase blood plasma and ultimately improve performance in hot and cool temperatures. Two forms of heat adaptation/training include heat acclamation and heat acclimatization. Both forms may take 7-14 days to see benefits of exposure. Heat acclamation: controlled heat exposure (sitting in a sauna). Heat Acclimatization: exposure to heat naturally in your environment (safely incorporating training in the heat).
• Time Training Sessions – Perform higher intensity sessions during the cooler times of the day. If you need to train during the heat of the day, save the lower intensity sessions for the hotter times of the day.
• Drink Up – Stay hydrated by consuming proper amounts of water and electrolytes. Unless you have a medical complication that is impacting electrolyte levels, refueling with only water during training sessions will further deplete electrolyte stores. Make sure you are aware of upcoming training sessions and when to pre-load in preparation for your training. Aim to start each session in a hydrated state.

Most athletes will lose 1-2 liters/hour.

Heavy sweaters may even lose close to 4 liters/per hour.

• Sweat test – Perform the test in varying temperatures to learn how much fluid you may be losing. Nailing your hydration and electrolyte needs before, during and after is imperative for optimizing your training as well as recovery for the next training session.
• Stay Cool – Determine cooling strategies that work for you. Consider staying in cooler temperatures leading up to a training session. Carry ice or frozen hydration that will melt throughout the session. Wear light colored clothing that breathes well and a hat.
• Pacing – Pacing properly is key. Managing pace early on reduces the risk of overheating later in the training/competition.
• Acceptance – Extreme heat will impact power and intensity. Accept that in extreme hot and humid temperatures, you are not as likely to perform at the higher intensities. Heat and humidity are limiting factors that stress the heartrate and cooling system.

Lastly, I want to discuss the impact heat has on your GI system.

Did you know gut issues are a main contributor for DNFs? WHY?!?

As heat increases, the stress your body feels when exercising increases. As I mentioned earlier, in extreme temperatures, there is competition for blood flow between the gut, muscles and skin. Blood flow is redirected to the skin to aid in cooling the body off. As a result, GI function slows and digestion/absorption rate slows in the gut, resulting in bloating and diarrhea.

Tips to combat GI issues:

1. Stay hydrated! Getting behind on your hydration can be the limiting factor that prevents you from finishing your training or competition.
2. Use multiple transportable carbohydrate = choose sports nutrition that has a blend of carbohydrates (fructose + glucose) rather than a single carbohydrate.
3. Train your gut! If you train under fueled and underhydrated and try to adjust in competition, your gut may not be able to handle the higher volume. When training, hydrate and fuel the way you will in competition.

It is summer and getting hotter. Athletes should be responsible in learning how to train in the heat, what their safe limitations are and strategies that help them stay cool.