101 – that’s how hot it’s been (or 38 degrees Celsius), depending on where you live. Maybe even hotter for you!
How can you ride in the heat and still have fun? How can you train effectively?
You’re the Reason Why You Get Hot. The human engine is very inefficient. Only about 20 – 40% of the calories you burn move you down the road. The other 60 – 80% generate heat, which must be dissipated. This is why you can feel hot when you’re riding briskly on a cool day.
How to Train in Hot Months
Joe Friel says, “An athlete should do the least amount of properly timed, specific training that brings about continual improvement.” Put more simply—no garbage miles! Every ride should have a specific purpose, and you should only do a ride when it will contribute to your fitness. Different types of riding bring about different physiological changes:
- Base endurance training. Base training increases the efficiency of your heart so that it pumps more blood and increases the blood flow to your skin, which helps with cooling.
- Tempo training. Riding at a brisk pace—you can talk but you can’t whistle—such as into a headwind or up a long climb builds aerobic fitness. As you become more aerobically fit, you start sweating at a lower core temperature. You also sweat more as the temperature rises than you would if you weren’t as fit. The result is that you can tolerate higher temperatures than if you weren’t as fit.
- Power training. Riding hard enough so that you can’t talk, but at a pace you can sustain for up to an hour (like racing a time trial) increases the power you can produce and also helps you acclimate to riding in a hot environment.
The physiological changes from both endurance and tempo training result from months of training. They are not short-term adaptations. Because both types of training require a fair amount of time in the saddle, if possible you should do these in the early part of your cycling season before your main season when you are riding in hot weather.
Intensity training, on the other hand, produces acclimatization in a matter of weeks. Intensity training builds on and is not a substitute for endurance and tempo training. For more on the different types of training and how to ramp up to your main season, see my eArticle on Intensity Training: Using Perceived Exertion, a Heart Rate monitor or Power Meter to Maximize Training Effectiveness.
How to Acclimate
When you acclimate, you start to sweat at a lower core temperature and you sweat more, which keeps your core temperature lower. Your total blood supply increases so that you can sweat more while still maintaining blood flow to the muscles. Thus you disperse more heat both by convection (the increased blood flow to the skin) and by radiation.
You can bring about these changes through long endurance rides in hot conditions. You can also adapt if you ride so that your core temperature rises 1.8 to 3.6 degrees Fahrenheit (1 to 2 degrees Celsius) for a period of 60 to 90 minutes. The fitter you are, the faster you will acclimate. Ride hard enough to sweat heavily for 60 to 90 minutes.
If you are already very fit, you can achieve significant acclimatization by riding this hard on four successive days. If you aren’t quite as fit, you may need as many as eight sessions with a rest day in between each session. If you live in an area where the summer isn’t hot all the time, you can acclimate by riding with enough clothing so that you sweat heavily, which is particularly easy if you ride a trainer in the sun without a fan for cooling.
How to Ride Without Overheating
During your main season and the hot summer months, you should continue each type of training, although with reduced total volume. You may enjoy weekend club rides. Or ride for fitness and relaxation. Or ride to prepare for a longer event such as a century. How can you do these without overheating badly?
- Study the weather and plan around it. Plan your hardest workouts for the cooler days.
- Adjust your expectations. When it’s really hot you can’t ride as hard or as long as you can when it’s just 10F (5.5C) cooler.
- Ride by effort, not pace. Riding when you are hot drives up your heart rate, so your heart rate monitor doesn’t provide useful information about how hard your muscles are working. If you use a power meter, it will accurately tell you how hard your muscles are working; however, because you can’t ride as hard when you are hot, gauge your effort by perceived exertion, not by your computer.
- Slow down. Since most of the heat comes from your working muscles, slowing down to reduce the internal heat generated helps you to deal with the external heat. If you ride a bit more slowly but don’t have heat-related problems, you’ll finish sooner than if you pushed the pace!
- Ride early. Get out before the heat of the day. I have clients in Arizona who train before sunrise.
- Take frequent breaks. If you are doing an endurance ride, stop as needed to cool down by resting in a cool environment. For example, get a healthy snack at a fast food place or minimart. A client raced all day across the Arizona desert when the high was near 120F (50C). He rode for about 90 minutes and then took a 15- to 30-minute break in his support van to cool down. Riding like this, he passed three riders who were trying to just keep pushing. You could do laps from your house and stop periodically back home to cool down and fully hydrate.
- Split your workouts. Start your endurance ride in the morning, take a break indoors for lunch (or breakfast) and to cool down, and then ride more after your break. Your total riding time can be longer so you’ll get more training benefit than trying to push through without a significant break.
- Ride indoors. Intensity workouts can be hard to do when it’s hot. Your legs are demanding so much blood that not enough goes to your skin for cooling, and you overheat. Try riding your intensity workouts on the trainer with a huge fan blowing on you and with two water bottles. It’s not much fun to do trainer rides like this, but at least they are short—and better than doing them in the sun!
- Use the wind. Climbing on a hot day, it’s harder to stay cool because you are going much more slowly. You can train for both short and sustained climbs by riding into the wind for about how long each climb would take you.
- Practice technique. During an easy endurance ride, throw in a few 20- to 30-second flat-out sprints in a hard gear. The purpose is to improve how your nervous system coordinates the firing of your muscle fibers, not to reach a specific power or heart rate. By improving your neuromuscular facilitation, you’ll increase your power. Because you aren’t trying to sustain a hard effort, allow plenty of recovery in between each sprint.
- Smile. In an experiment 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 15, 25 and 35C (59, 77, 95F). Based solely on perceived effort, their power output declined as the temperature rose. Instead of complaining about the heat accept it.
Cycling in the Heat Bundle
You can learn more about the science of riding in the heat, and managing your fluids and electrolytes, in my two-part eArticle series:
- Cycling in the Heat, Part 1: Ride Management is 19 pages and covers how to acclimate to hot conditions, how to train in hot months, what to wear, eat and drink, how to cool down if you overheat, and how to deal with heat-related problems.
- Cycling in the Heat, Part 2: Hydration Management is 21 pages and covers how to determine how much you should drink depending on your physiology and sweat rate, how best to replace your fluids and electrolytes, the contents of different sports drinks, how to make your own electrolyte replacement drinks, how to rehydrate after a ride, and how to deal with hydration-related problems.
The cost-saving bundled eArticles totaling 40 pages Cycling in the Heat Parts 1 and 2 are just $8.98 (a 10% savings) and, as always, just $7.64 for our Premium Members (includes their everyday 15% discount!).
Coach John Hughes earned coaching certifications from USA Cycling and the National Strength and Conditioning Association. John’s cycling career includes course records in the Boston-Montreal-Boston 1200-km randonnée and the Furnace Creek 508, a Race Across AMerica (RAAM) qualifier. He has ridden solo RAAM twice and is a 5-time finisher of the 1200-km Paris-Brest-Paris. He has written nearly 30 eBooks and eArticles on cycling training and nutrition, available in RBR’s eBookstore at Coach John Hughes. Click to read John's full bio.