Is hot weather an easy excuse or a serious health risk?
Exercising in the heat can damage your health. If you want an intense workout when it’s hot outside, you need to wait until things cool down or head indoors to air-conditioning. The “go hard or go home” mantra is not appropriate in high heat. If you push your body too far, you risk overheating your insides and causing heat stroke.
Your body has inbuilt cooling systems. When you exercise, your muscles give off heat. Your body gets rid of that excess heat by producing sweat. The sweat evaporates on your skin, which cools you down. At the same time, your blood rushes to your skin to help it cool down. This leaves less blood for your muscles, which in turn increases your heart rate and lowers your blood pressure. When it’s hot, your body has to deal with external and internal heat. And, if it’s very humid, your sweat can’t evaporate because the air is already full of moisture. Your body becomes unable to cool down, virtually causing your insides to cook.
How hot is too hot?
This depends on two things: the humidity, and your acclimatisation. First, humidity. When the air is humid, it’s hard for your sweat to evaporate, so your body struggles to cool down. That’s why you can often feel more exhausted in humidity than in high heat. Second, if you’ve been living in a hot climate for a while, you’ll fare better than someone on holidays. Your body can adjust to the heat – but probably not as much as you think. And remember, it takes at least 14 days for your body to acclimatise.
Does hydration help?
Sure, but you can still get heat exhaustion and heat stroke if you’re hydrated. Drinking water and other fluids is essential when exercising in the heat, but it doesn’t make it safe. It simply helps prevent dehydration. Dr Cedric Bryant, a fitness expert for the American Council on Exercise, recommends drinking water before and during exercise when it’s hot. Drink two to four cups of water a few hours before you exercise, and another one or two cups every 15 to 20 minutes during exercise.
Tips for exercising when it’s hot
- Exercise early in the morning before 6am, when it’s cooler.
- Head indoors to an air-conditioned space, such as a gym.
- If you must exercise when it is hot, take it easy. This is not the time to push yourself.
- Wear light, breathable clothing. Avoid dark and synthetic fabric.
- Exercise in the rain. Wait for those afternoon showers to come in, and head outside (just not in a thunderstorm!)
- Exercise in water. Swimming, surfing, or even walking in water is great exercise.