Listen to Your Heart (Rate)

by | Updated: December 3rd, 2016 | Read time: 2 minutes

Q: Why do I feel so sluggish during the summer when I should be at peak performance?

Amy Marsh answers

A: The simple answer is the heat. Even though you have the heart of an athlete, you’re susceptible to an increased heart rate in warmer weather. Don’t over-think or over-analyze a bad workout. Instead, understand the science behind it so you can adjust accordingly. There’s a perfectly good explanation…and solution.

During the summer months, heat can play a large part in how you perform. Knowing why this happens and how to adapt to it will help you push through — mentally and physically.

Why: Humidity and high temperatures put extra stress on the body. For one, your heart is forced to beat faster in order to quickly pump blood to the skin to cool you down. This reduces the blood flow to your muscles. Less blood flow means that less oxygen and other key nutrients are being shuttled to your muscles. It may feel as if you’re working twice as hard to run at a pace which is usually easy.

Listen to Your Heart (Rate)Your body’s natural reaction is to sweat, because this is your internal air conditioning system. However, when the humidity is up and the air feels a little thick, sweat doesn’t evaporate as easily, which increases your core body temperature. If you’re not careful, you could be at risk of serious illness such as heat exhaustion or heat stroke.

How: First, be cognizant of the warning signs: fatigue, nausea and/or dizziness. To help prevent these symptoms listen to your body, specifically your heart rate. Know what your average heart rate is while exercising at a certain pace, so you can identify when it’s above your norm. You can monitor this with your watch, either by manually calculating the beats per minute (count the number of beats over 10 seconds and multiply by 6) or by wearing a sensor strap which communicates directly to your watch.  You may also need more fuel during hot workouts to maintain energy levels. Because caffeine can raise your heart rate even more, stick to gels that are caffeine-free or provide vitamin-based energy boosts.

Your second line of defense is to keep your core temperature down. Hydration is obviously crucial in this process, so don’t wait until you’re thirsty to drink. Consider a sports drink if the workout is intense or lasts longer than 90 minutes. Another core-cooling method is to apply ice or cold cloths to your pressure points: under arms, behind the ears and around the wrists.

Before you even step outside, make sure you’re wearing light-weight, light-colored clothing. Also, apply sunscreen to all exposed skin and top your head with a visor for sun protection and some extra shade.