Let's take a look at what cyclists should know about racing and training in hot weather, tips for staying cool, and warning signs of heat illnesses in yourself and others.
Temperatures are warming up across the United States as Spring arrives. Some parts of SoCal will have a 40 degree temperature swing in about 48 hours, with many residents experiencing 100 degree heat for the first time this year. Cycling in these conditions can be challenging, and even dangerous. We know that controlling a rider's core temperature is key to athletic performance, so proper preparation can affect your race results, too!
* This article is not a substitute for medical advice or first aid training. You should consult a doctor about your exercise program.*
What's the risk?
Heat-related illnesses happen exponentially more in temperatures above 90 degrees, and are also more common in humidity - keep an eye on the "heat index" (a combination of the base temperature and the effect of humidity) and be aware that relative humidity over 60 slows sweat evaporation, which further hurts your ability to cool yourself through sweating.
Riders in warmer temperatures are at risk for the 3 heat-related illnesses: heat cramps, heat exhaustion, and heat stroke. These illnesses can cause brain or organ damage, and death in extreme cases.
As a cyclist who races and trains in the heat, you should know the signs of these heat-related illnesses in yourself and in your riding partners.
Acclimating to riding in the heat
Temperatures in the American Southwest can be shocking for riders visiting from cooler climates. That first really hot day can even surprise the local residents, especially after a long period of cooler Winter temperatures. It can take up to two weeks for a physiological response to occur that better prepares you for the heat.
Carry far more fluid than you think you need, so that you have extra water available in case your ride goes longer than planned (what if you get lost? have a puncture? crash?) If your bike is limited to two water bottle cages, add more bottles to rear jersey pockets or consider using a hydration pack.
Reduce alcohol and caffeine
We cyclists love our beer and coffee, but they don't help with heat related illnesses - consider reducing or eliminating them, especially before harder, longer efforts in the heat. A sports drink with salt/electrolytes can help replace what is lost during exercise in heat as well.
Ease into it
It's important to find out how your body responds to higher temperatures, and every rider is different. Don't make your first ride in warmer temperatures a difficult workout - give it a chance to see how your body responds on an easier, shorter, closer to home ride first, then slowly raise the intensity and distance based on how you feel.
Muscle cramps are one of three "heat illnesses" that can affect athletes and are often one of the first signs of the body having a hard time coping with the effort during warm temperatures.
Fatigued muscles (like calves or quads in cyclists) are often the first to exhibit uncontrollable cramping. It's generally believed to be caused by loss of electrolytes during exercise, which are lost through sweat. If you drink a lot of plain water and suffer from cramps, adding a sports drink containing electrolytes to your workout regime is an inexpensive and easy treatment to try.
Cramps generally aren't serious and usually go away on their own if you simply drink some fluids and rest. Monitor symptoms to make sure they aren't progressing toward heat exhaustion or heat stroke.
Know the signs of heat exhaustion
Heat exhaustion is caused by loss of fluid and/or electrolytes and often occurs after exposure to high temperatures. Although it's not as serious as heat stroke, it's still a medical emergency and demands immediate response. Heat exhaustion often goes hand-in-hand with dehydration.
- Signs of dehydration-based heat exhaustion include: thirst, weakness, headache, and losing consciousness.
- Signs of heat exhaustion due to electrolyte loss are vomiting, nausea, cramping, and dizziness
- Heavy sweating may occur as your body tries to cool itself
A riding partner with heat exhaustion might appear confused, disoriented, or have dark-colored urine.
Heat exhaustion can progress to heat stroke if left un-addressed. If you, or a riding partner, are exhibiting these symptoms, get out of the heat as soon as possible and into an air-conditioned room or shady place.
A cool shower or bath, fans, and applying cold towels can help the affected rider recover.
Know the signs of heat stroke
Heat stroke is a core body temperature of 104 degrees Fahrenheit or higher, brought on by extended exposure to heat in combination with dehydration.
Heat stroke can lead to brain or organ damage, and in extreme cases, death. Heat exhaustion can progress into heat stroke. Some of the symptoms of heat stroke are similar to those of heat exhaustion, with the addition of seizures, rapid breathing and/or heartbeat - but unlike heat exhaustion, the skin might be dry, hot, and red. There is also absence of sweating, even in the hottest temperatures.
Call 911 if you believe you, or someone else, have heat stroke. Until help arrives, render first aid - move to a cooler location - in the shade, or indoors in air conditioning if possible, apply ice packs, use a fan, cold showers or baths - any resource available to you to help lower core body temperature.
Training in the heat
Doing training rides in the heat (carefully) is a good way to test your body response to warmer temperatures, before you race. You'll need to hydrate effectively - some riders might need two bottles per hour in extreme conditions. Weighing yourself before and after your rides can provide you with insight and let you know how much you're losing due to sweat. I like to freeze my bottles so they melt during the ride, providing colder fluid to help lower my core temperature.
If your training permits, consider riding early in the morning or later in the evening, avoiding the full force of the afternoon sun. Riding trails at night with lights is great fun and a wonderful change of pace from your usual routing.
You can also vary your route. Slow, steep climbs reduce the amount of cooling airflow that passes over your body while riding. You might consider staying on the flats, where speeds are higher (and thus there is more of a cooling effect from the airflow) on the hottest days.
Equipment choices matter too:
- wear moisture-wicking clothing and a vented, breathable helmet
- use a sunscreen. Here in California, sunscreen for riding is a daily occurrence, but if you've got out of the habit because you've been riding in grey, overcast weather, don't forget to start using sunscreen again as the sun comes out. Here are my favorite sunscreen products for cyclists.
- Gloves to protect the back of your hands
Racing in the heat
The unique challenges of racing are even tougher in the heat. You can re-schedule training rides for cooler parts of the day, but that's not possible on race day. We know that athletic performance is reduced in the heat, as the athlete's core temperature rises, so your response to the heat can easily affect whether you make the podium.
Riders have come up with some creative strategies to stay cool while getting ready to race:
- Wearing a cooling vest
- Warming up in an air-conditioned space (this technique was famously used by Jan Ullrich when he defeated Lance Armstrong in an individual time trial on a very hot day.) Ullrich rented an air conditioned bike shop, Armstrong warmed up on a trainer outside in the heat, which affected his race performance.
- Use the "pantyhose" technique - you may have seen riders warming up with these draped around their neck. It's an inexpensive way to stay cool. Simply chop the legs off a pair of pantyhose, fill the leg with ice cubes or ice chips, and then tie the top in a knot. Drape it over your shoulders and it will cool you as it melts, then discard at the starting line.
- Have a helper provide an umbrella for shade while you're in the starting grid
I hope you've got some ideas to ride safer and stay cooler this Summer. Take care.