by Coach David Ertl

In the past couple of blogs I’ve been dealing with the 4 H’s of RAGBRAI. This blog covers the final two, Heat and Humidity. I will deal with these together because they are related and should be dealt with in much the same.

One thing is for sure, RAGBRAI seems to always land during the hottest, most humid week of the year in Iowa. Be prepared for temperatures in the 90’s (F) and high humidity. This doesn’t always happens but you should be expecting it. Dealing with this heat and humidity requires some precaution.

It is important to maintain a safe body temperature when exercising in high heat and humidity. When you exercise, you generate a lot of excess body heat that is removed from the body through sweating.  As sweat evaporates from your skin, it cools you off and helps reduce your core temperature. The problem with humidity is that the sweat does not evaporate very well.  When sweat starts to drop off of you, you know it is not being totally effective.  Now one positive thing about cycling as a form of exercise is that you are constantly generating your own breeze.  Even if there isn’t a breeze blowing, if you are riding along at 15 mph, you are generating a 15 mph breeze which helps cool you off. You have probably noticed how hot it feels when you stop after riding on a hot day.  If you are feeling overheated, back off on your pace and pedal easier.  The easier you work, the less heat you generate.

Many of the miles on RAGBRAI are out in the sunshine.  The unofficial state tree of Iowa is corn, which doesn’t provide any shade for you while riding.  You will be out in the sun most of the day while riding and not much shade.  So to help reduce the heating effect of the sun, you should weight light colored clothing such as a white jersey.  Dark colored jerseys will trap the sun’s heat and make you even hotter.  Also, avoid wearing cotton shirts which do not release moisture very quickly. Synthetic fabrics dry quickly and help with the cooling effect. If you are starting to feel the effects of heat, as you reach each town seek out some shade, preferably in a breezy location and allow yourself to cool off before heading out for the next stretch. Some town offer hoses to spray you off.  If you are hot, nothing feels more wonderful that getting sprayed with cool water.   You can also do this yourself. If feeling very hot, splash some water from your water bottle over your head and down your arms and legs. You will feel some immediate relief.  Just make sure you don’t use your Gatorade bottle!

The other important component to dealing with heat and humidity is staying hydrated.  You can literally see the water leaving your body through sweat on hot and humid days. You need to stay hydrated so that your body can continue to sweat and cool you off.  On hot, humid days you should be constantly sipping on liquids.  You should consider bringing two water bottles on your bikes, although there are usually places all along the route when you can get water or other beverages.   While it is important to stay hydrated, you don’t want to go overboard on the drinking. There is some debate currently on how much is necessary to consume.  You should certainly drink to satisfy thirst but on very hot days that may not be adequate. On the other hand you don’t want to force yourself to drink to the point you are uncomfortable. You don’t want a sloshing stomach.  Water is great but you shouldn’t just rely on that. You lose a lot of electrolytes (sodium, potassium, calcium) when you sweat a lot and should replace these.  All sports drinks contain these so you consider alternating between water and a sports drink throughout the day.

Heat exhaustion is serious and you should be aware of its symptoms, which includes headache, cramps, nausea and chills or goosebumps.  If you notice any of these you should stop, get something cold to drink, find shade and cool off.  Don’t hesitate to notify a medical personnel if you are concerned about your condition.

One last comment. I know a lot of people prefer to get up and ride early in the morning on RAGBRAI to avoid the heat of the day out on the road. That’s a great strategy. But for training, don’t do all your rides in the early morning.  Get out and do some riding in the heat of the day to build up some tolerance to it, and to practice dealing with the heat.

With some care and attention, you should be able to handle all the heat and humidity that Iowa throws at you in July.

Coach David Ertl

David Ertl is a USA Cycling Level 1 Coach. He coaches the Des Moines Cycle Club Race Team and individual cyclists through the Peaks Coaching Group. He also provides cycling training plans and ebooks at his website: . He can be contacted at