You can get hot even when it’s not hot outside. Climbing or riding the trainer, for example. Why? Your engine is only 20 - 40% efficient. Of the calories your muscles burn, 60 - 80% produce heat, not forward motion. You need to disperse that heat or your core temperature will start to rise and your performance will diminish. You may start to suffer from heat exhaustion, which, if not treated, could develop into heat stroke, a potentially fatal condition.

Performance falls off even at moderately warm temperatures. A group of trained cyclists was asked to ride at the same perceived effort they would expend if riding a 20- to 40K-time trial. They repeated the trial rides at temperatures of 59, 77, 95F (15, 25 and 35C). Based solely on perceived effort, their power output declined as the temperature rose. At what you and I would consider a comfortable riding temperature they weren’t performing as well as at a cooler temperature!

Increasing your sweat rate and radiation from increased blood flow to the skin account for about 85% of your body’s cooling.

• Build Fitness Early—The fitter you are when hot weather arrives (or you start riding hard), the more readily you’ll adapt. Base endurance training increases both the amount of blood your heart can pump per stroke and the blood flow to the skin, both of which are key to cooling down.
  Information on: Endurance Training
• Pick Your Time to Ride—I have clients in Arizona who ride before dawn! That may be a bit extreme, but it’s coolest just before and after dawn.
• Ride Outdoors for Endurance—Since your core temperature is primarily the result of how hard you are riding, use you outdoor rides to build or maintain your endurance.
• Ride Indoors for Intensity—When you are riding hard you are generating a lot of heat. You’ll have a better quality workout if you ride in a cool environment with a big fan.
  Information on: Intensity Training.
• Slow Down and Ride by Effort, not Pace—Most of the heat you feel and sweat you produce is from your working muscles so slow down. Your heart rate rises when you get hot, so ride by perceived exertion, not heart rate.
• Light Colored Clothing Helps—Light colored clothing helps to prevent solar gain; however, when it’s on the skin in interferes with the evaporation of sweat, so wear loose clothing.
• Keep Head Bare— The skin on your scalp has a high concentration of blood vessels, which dissipate heat. Riding with a bare head (except for a helmet and sweatband). Anything else that covers your head is just another layer that sweat has to penetrate to cool you.
• Ride Outdoors for Endurance—Since your core temperature is primarily the result of how hard you are riding, use you outdoor rides to build or maintain your endurance.
• Prevent Cramps—Neuromuscular fatigue (so the nerves become more excitable) and sodium depletion are the main causes of cramps.
  Information on: Preventing and treating cramps
• Symptoms of Heat Exhaustion—Know the symptoms of heat exhaustion:
  Information on: Heat exhaustion
• Symptoms of Heat Stroke—Heat stroke is a medical emergency. Know the symptoms and if someone develops them, call 911.
  Information on: Heat stroke

Recent research even shows that training in the heat yields more improvement than training in cool conditions! Twenty very fit cyclists’ one-hour time trial performance was tested in 55F (13C) conditions. Twelve of the riders trained for 10 days in hot conditions of 104F (40C) riding at 50% of VO2 max, i.e., hard enough to acclimate to the heat, but not hard enough to induce training adaptations for the highly trained athletes. The other eight did the same workouts at 55F (13C). All the subjects were then retested. The 12 who had acclimated to the heat improved their time trial performance by 6% in cool conditions and 8% in hot conditions. The cyclists who trained in cool conditions showed no improvement.

Through careful ride management you can achieve your goals in both moderate and hot conditions, whether you ride for fun, fitness or performance.

Remember: riding in the heat isn’t just about riding when it’s hot outside.

More Information

• Cycling in the Heat Bundle Parts 1 and 2 — 41 pages for $8.98, a 10% discount, from RoadBikeRider.com. It includes:
1. Cycling in the Heat Part 1: Ride Management — How to acclimate, how to ride in the heat, what to eat and heat-related problems. 19 page eArticle for just $4.99 from RoadBikeRider.com.
2. Cycling in the Heat Part 2: Hydration Management — Develop your personal hydration and electrolyte plan. 21 page eArticle for $4.99 from RoadBikeRider.com.
• Cramping: How to prevent and deal with cramps — my 10-page eArticle for $4.99 from RoadBikeRider.com.
• Nutrition for 100K and Beyond: Cycling nutrition, hydration and electrolytes — my 16-page eArticle for $4.99 from RoadBikeRider.com.
• Eating & Drinking Like the Pros: Expert advice on cycling nutrition and how to make your own healthy nutrition at lower cost — my 15-page eArticle for $4.99 from RoadBikeRider.com.
• Other articles by Coach Hughes from RoadBikeRider.com