As we roll into the dog days of summer, we’re subjected to the hottest and most humid days of the year. So let’s be a little extra cautious when exercising.
How does the body cool?
There are four mechanisms that our bodies use to cool off: Radiation, Evaporation, Conduction, and Convection.
- Radiation is the heat leaving the body into the surrounding atmosphere.
- Convection is air (or water if you’re swimming) flowing by the body, taking away heat.
- Evaporation is your sweat evaporating, causing a cooling effect.
- Conduction is your skin coming into contact with something cooler, transferring heat.
Radiation, Convection, and Evaporation are all our friends and work together perfectly to keep us cool. Conduction, not so much in cycling. Unless you hold that frozen water bottle to your neck for a quick relief.
However, if the temperature outside is hotter than our bodies, radiation cannot work. The heat goes in the other direction into our bodies.
And if the air is very humid, evaporation cannot work.
Luckily, convection is always at play when we’re moving at 20mph, and it still feels good.
But when you stop, boy can you feel it.
The downside of the efficient cooling effect that we get from cycling is that we can feel more comfortable than we should. And dehydration is a big risk.
Many cyclists say, “Drink before you’re thirsty”, which is great advice especially in hot weather. This is not the time to pack light with only one water bottle. And make it a point to take a sip every 15 minutes, or 5 miles, to replenish what you’re losing.
When it’s super hot and humid, plan to take it easy on yourself. Maybe do a recovery pace. Or map out a route that doesn’t have your normal hills. (thought he downhills are always good for cooling off).
Or if you’re on a longer ride, be sure to loop in a place to refill the water bottles.
What to drink?
When it’s hot and humid, the most important thing is water. You can go with your electrolytes and sugary drinks, but I always like to mix it up with both a sports drink and some plain water to wash it down.
What to wear?
Nothing would be best. But if that doesn’t seem appropriate (there are lots of naked bike rides you can join), wear something that the wind can get through, and this is a great time to choose the shirt with the full zipper front.
Most importantly, take it easy, and listen extra carefully to what your body is telling you.