Runners are a dedicated bunch.  Most pound the pavement in every kind of weather: rain, snow, hail and even the blazing heat.  But did you know that running in the hot summer heat can actually be hazardous to your health if not approached correctly?  It absolutely can – here’s an overview of how and why, and what you can do to minimize your risk this summer season.
Why can running in the heat dangerous?
Air quality is lowest in the summer months, particularly in urban areas like Toronto, which means that there are more pollutants in the air than any other time of year. When you exercise, your heart rate increases causing you to breathe faster and heavier, taking in more air than when at rest. Inhaling a large volume of low-quality air can reduce the function of your lungs, cause inflammation, swelling, chest pain and coughing for days following your run.

You may be surprised to learn that many doctors compare running in smoggy conditions to smoking cigarettes. This is because once the inhaled pollutants enter your blood stream, they make the cholesterol more “sticky” which increases the likelihood of blockages that can result in heart attacks. And it doesn’t end there: running in the heat can also lead to dehydration, heat stroke, heat cramps and heat exhaustion.

Below is a list of tips to help keep you running safely in the summer heat.

1.    Check the Air Quality Health Index. In Canada, you can check the air quality for your city (and even your neighbourhood) at any given time to determine whether it is safe to run outside. If the air quality is poor, opt for an indoor treadmill run instead (or see #3).

2.    Hydrate, hydrate, hydrate. Drink water (and lots of it) before, during and after your run. You can even weigh yourself directly before a run and after – if you have lost weight, it means you sweat more than you drank and you need to drink more next time.  Take either a water belt or a hand held water bottle with you.

3.    Keep it early or late. The temperatures are lower in the early morning and in the evening. Avoid running in the middle of the day or during rush hour when there are more vehicles on the road and therefore pollutants in the air.

4.    Dress appropriately. Wear a hat, sunglasses and moisture-wicking clothing in light colours. You may even want to soak your hat before you leave or at any water fountains you pass to keep your head cool.

5.    Allow for acclimation. If you’re not used to running in the heat, don’t expect to set a personal best the first time you try. Instead, slow your pace down, decrease your distance and allow yourself to take breaks whenever needed.

Your best bet for hot-weather running is a shady trail with soft terrian, like Toronto’s beltline trail.

6.    Find the shade. A shady trail is hands-down the best place to run in the heat because it offers protection from the added heat of the sun.  An added

7.    Avoid concrete. If you can’t find a trail, at least opt for a pathway or grass as opposed to concrete. Concrete retains heat which can make it harder for you to keep your temperature down.

By following these tips, you will not only increase the safety of your runs, but also your comfort and enjoyment during them. Happy running!