Toronto in July: the humidex says 38, your program says back squats. Here is how to workout in the heat without turning a good session into a bad afternoon.
Can you still workout in the heat?
Yes, mostly. But heat is a second stress stacked on top of your training stress. Your heart rate runs higher at the same effort, you sweat more, and everything feels harder than it did in May.
So the same session is a bigger ask. My position: in July, train by effort, not by the numbers on the whiteboard. If the prescribed weight feels like a grind on the first set, drop it 5 to 10 percent and move on. Nobody ever got fitter by getting heat-sick.
Pick your window: early or late
The easiest way to workout in the heat is to dodge the worst of it. In Toronto the hottest, stickiest stretch is usually early afternoon into early evening, after the sun has had all day to cook the pavement.
- Early morning: The city has cooled overnight. Our Brock gym in Parkdale has open gym from 4am daily, so a pre-work session is on the table.
- Late evening or overnight: The Dundas gym in the West Junction is open 24/7, so you can wait for the humidity to break.
- Outdoors: If you run in High Park or along the lake, go at sunrise. Shade and a breeze beat any hydration hack.
Check the forecast before you commit. The City of Toronto points residents to Environment and Climate Change Canada for local weather alerts, and the WeatherCAN app puts them on your phone.
Hydrate before you need it
Thirst is a late signal. Drink water steadily through the day, not just during the session. Health Canada's advice for extreme heat is simple: drink water regularly.
A rough check: if your pee is dark and you're peeing less than usual, you're behind. Health Canada actually lists dark urine and decreased urination among the signs of heat exhaustion.
For most of our sessions, which run about an hour, water is enough. If you're a heavy sweater, training for a long stretch, or you notice white salt marks on your shirt, an electrolyte drink can help. Don't chug a litre in one go right before a squat set. Sip.
Give yourself a week or two to adapt
Your body gets better at handling heat if you give it time. Heat acclimatization takes roughly one to two weeks of regular, gradual exposure. During a first heat wave, shorten the session, lengthen the rests, and keep the intensity honest.
If you're coming back from a holiday somewhere cooler, treat your first few Toronto summer sessions like a fresh start. You'll feel the difference by the second week.
How to cool down properly
Cooling down in the heat is less about stretching and more about lowering your core temperature.
- Walk for a few minutes after the last set instead of stopping dead.
- Cold water on your neck, wrists and face.
- Get out of the sun and into shade or air conditioning.
- Wear loose, light-coloured, breathable clothing. That's straight from Health Canada.
- Take a cool shower when you get home.
Toronto also lists more than 500 cooling spaces across the city, plus pools and splash pads. If your home runs hot, they're worth knowing about.
Know the warning signs
This is the part to read twice. Health Canada lists these as signs of heat exhaustion: heavy sweating, headache, muscle cramps, dizziness or fainting, nausea or vomiting, rapid heartbeat, extreme thirst, and confusion.
Heat stroke is different and serious. Confusion, lack of coordination, fainting, and hot skin that can look red and dry or damp are red flags. Health Canada calls it a medical emergency: call 911.
If you feel off, stop. Get to a cool place, sip water, and cool your skin. Don't be a hero. Some medications and health conditions change how you handle heat, so if that's you, talk to your doctor or pharmacist before you ramp up summer training. You can read the full guidance in Health Canada's staying healthy in the heat fact sheet.
Our small group classes cap at 8, so a coach can spot a person who's gone grey and quiet. Find your options on the classes page, or use open gym and train on your own schedule.
Quick answers
Is it safe to workout in the heat?
For most healthy adults, yes, with sensible changes: train in cooler hours, hydrate, scale the intensity, and stop at the first warning signs. If you have a health condition, check with your doctor.
What's the best time to train in a Toronto summer?
Early morning or late evening. Both our gyms have extended hours, with open gym at Brock from 4am and at Dundas 24/7.
How much water should I drink?
Sip steadily through the day and during the session. A pale yellow pee is a decent everyday guide. Health Canada says to drink water regularly in extreme heat.
When should I stop mid-workout?
Stop if you get dizzy, nauseous, confused, or stop sweating when you should be. Cool down, drink water, and call 911 if it looks like heat stroke.
Train early, train smart
Come see both gyms and find the training window that fits your summer.