I’m no expert, but…
Many articles by experts offer deep science about body heat, fluids, and other stuff. And if all those numbers and matrices make you feel more confident, then, by all means, read the articles. As for me, I’m not an expert in physiology, but I’ve survived some pretty stupid stunts while in the saddle, and I'd like to share some wisdom from practical experience. I’ve ridden my bike in the 115+ degree heat of the parched Sonoran Desert of Arizona, as well as the 98 degrees, 96 percent humidity of the Gulf Coast states. And while everyone tolerates heat differently, the following pointers will give you some measure of safety when riding in the summer heat.
Listen to your body
The first and most important rule is: Use common sense. You can’t ride in the summer heat at the same intensity you ride in the 60 and 70-degree temps of spring and expect to stay well. Your body is highly adaptive, but you need to build up your heat coping mechanism gradually. Spend the first couple of weeks cycling in the summer heat by “working into it.” Listen when your body talks to you. If you’re feeling weak, dizzy, or chilled, when you should be feeling hot, your body is over-stressed, and you should stop and reevaluate your physical and mental condition.
Schedule your rides better
Avoid the heat of the day. Schedule your rides in the early morning or the early evening when the sun less intense. Or, scout out some new routes that provide more shade and places to stop that provide shelter from the sun.
Discover your best hydration practice
Learn how to drink. In other words, don’t ride hard for 45 minutes and then slam 20 ounces of water to catch up. Sip your fluids a couple of gulps every few minutes. When I’m out on a hot day, I drink approximately every 4-miles: a gulp of Gatorade with two gulps of water after it. But everyone is different. You’ll have to discover your own rate of hydration, but it should have consistency.
Learn what to drink
Water is a given, but you need more than water. You need a mineral and electrolyte replacement drink. Blood doesn’t work well if it gets too watered down; it’s a condition called hyponatremia. It can occur on a hot, sweaty day when you drink only water for an extended period. The main ingredients that help keep you stabilized are sodium, potassium, chloride, and magnesium. These are available in many sports drinks and water additives. I often drink Gatorade, but not all cyclists can tolerate Gatorade. Some of the other products available are NUUN, Clif Shots, and Accelerade, to name just a few. If you get too dehydrated or too “watered down,” your endurance wanes, recovery takes longer, or worse, you could put your body in a dangerous condition. Experiment with hydration to see what works best for you and what your stomach can tolerate.
Another way to maintain sodium in your blood on a hot, sweaty day is to try munching on salty foods along your ride. Salted peanuts, beef jerky, or similar prepared foods help you maintain your sodium levels. I know a few long-distance cyclists who buy one of those jumbo dill pickles at every convenience store stop.
Your drink bottles get warm on a hot day. Stop at a convenience store and put some ice in your drinks or buy a cold drink. Putting cool fluids into your system will help keep your core temperature down. Experimentation is in order here as well. Super cold water on a hot ride gives some riders stomach cramps, so go easy at first.
And finally, water is not just for drinking. If you have an ample supply and need a cool down, consider pouring water over your head, down your neck, or over your shoulders. It can provide some welcome relief in the heat of the day. The same is true for an ice sock. I’ve never used one, but I’m told it works well.
Reflect and dissipate heat
I love cotton fabric. But not for cycling on hot days. Cotton gets wet and stays wet. It can’t effectively wick the sweat from your body, and when it’s stuck to your skin with sweat, it won’t allow you to dissipate heat. There are many performance fabrics available that are better for summer cycling. Check out Boure’, or PEARL iZUMi. Read what they have to say about their clothing, and you’ll see the benefits.
Also, give some thought to light colors to reflect the sun and long sleeves to keep the sun off your arms. There’s a good reason desert dwellers cover-up, no matter how high the temperature. I wear a long-sleeved summer jersey, and it works very well to keep my skin surface from overheating.
Use a helmet with adequate ventilation. Here’s a look at the styles of helmets available; you’ll notice some are well vented, and some are not. On a hot summer day, you’re going to want some air circulating over the top of your head.
Common sense, acclimatization, and proper hydration will help you steer clear of over-heating while riding in high temps and humidity. The bottom line on all of this is to understand the messages your body sends and know its limitations. Everyone is unique, so experiment to see what works best for you and enjoy riding this summer. You might also consider joining the National Bike Challenge. It’s FREE, FUN, and you might even win a prize.