When Is It Too Hot For Intense Exercise?
By Dave Smith
The air conditioner just had to break on the hottest day of the summer.And, of course it had to happen just before dozens of clients were about to show up for boot camp class. It was Murphy’s Law in action.
As the gym owner, what was I supposed to do? Let my clients exercise in the sweltering heat? Or, turn them away, causing inconvenience for them and lost revenue for me?
Maybe your gym air conditioner won’t die at the worst possible time like mine did, but you might face a similar dilemma in the coming months. Whether you’re running an outdoor boot camp class, hosting a running club, or even teaching yoga in the park, what are you going to do on the hottest days of summer? Will you let your clients exercise?
Before finding yourself in that situation, it’s important to have some guidelines in place to help you make a wise decision.
How Hot Is Too Hot?
The “heat index” is a temperature measurement that combines the humidity of the air to the actual outdoor temperature. A day with high humidity might “feel like” it’s much hotter outside than a thermometer would actually show.
Exercise researchers have used the heat index to determine what exercise is considered safe in certain heat conditions:
- When it feels like 28 degrees Celsius(82 Fahrenheit) outside, it is recommended that continuous physical activity not exceed one hour in length.
- When temperatures hit 30-32C(86-90F), all exercise for “less-fit” populations should be cancelled, and exercise for “fit” individuals should be limited and reduced in intensity.
- Above 32C(90F), strenuous exercise should be stopped for all individuals.
You can check your local weather to find out what heat index is expected each day. Use this forecast to plan ahead for your outdoor fitness training.
What’s At Risk?
It might be tempting to “push through” the heat, but that isn’t a safe choice.
Even when the heat index is relatively low, outdoor exercise can fatigue your clients much faster than they would experience when exercising indoors. This can lead to dizziness and stomach upset.
As heat and humidity rise, so does the chance of sunstroke, muscle cramps, heat exhaustion, and eventually heatstroke, which is accompanied by fever and often unconsciousness.
Heatstroke is a serious condition at which point your client’s body is no longer able to regulate its own temperature.This requires immediate emergency treatment. You do not want to be responsible for your clients suffering from heat stroke.
What Can You Do as a Fitness Professional?
- Be smart.The simplest action is one we’ve already discussed: As temperatures rise, watch your local heat index to make a safe judgment call about outdoor exercise you have planned for that day.
- Be flexible.If you do decide to carry on with outdoor exercise during hot weather, be prepared to modify your plans as needed. Keep a careful eye on your clients to look for signs of fatigue due to heat (e.g. perfuse sweating, flushed skin, complaints of dizziness, etc.). During hot weather it is not the time to play “drill sergeant” by pushing your clients to do more and work harder. Consider shortening your workouts or offering alternatives to any high-intensity activities you might have originally scheduled.
- Be prepared.Bring cold water in case your clients run out. If you’re exercising in an area where there is no natural shade, bring an umbrella or shade tent for your clients to use.
Summer is a great time to get your clients outdoors for some fun-in-the-sun exercise, but as a fitness professional, it’s your job to keep them safe above all else.