Q. I've become a big mountain biker. Unfortunately, it seems like I'm always biking in the heat of the afternoon sun on the most hot and humid of days. Since I'm not going to give up biking and my schedule doesn't permit me to go at any other (cooler) time, what kind of precautions should I take to avoid sun or heat stroke?
A. This is one of my favorite topics. I've needed to make sure I took in enough fluids while bicycle racing, running marathons, hiking in the mountains, sailboat racing, even cross-country skiing. There is absolutely no time anyone outdoors can ignore the need to replenish the fluids lost through exercising.
Drink up, drink up! You can survive the hottest, most humid conditions as long as you take in enough fluids during your bike rides. This advice goes for anyone exercising outdoors in the summer months, not just endurance athletes.
To start out with, you should have two water bottle cages on your bike. Use the larger sized 24 ounce bottles, instead of the traditional 20 ounce bottle. If you're not spending more than 90 minutes riding, those two bottles (a quart and a half total), should be enough. Drink the same way they vote in < xml="true" ns="urn:schemas-microsoft-com:office:smarttags" prefix="st1" namespace="">Chicago -- early and often. That may sound like a lot of water for a 90 minute ride, but if you drink every 10-15 minutes, and not small sips, but big healthy swallows of 6-10 ounces each time, you won't have any water left by the end of your ride.
And another thing -- the colder the water, the better. Forget any nonsense you might have heard about cold water causing cramps. Studies have shown that cold water gets out of your stomach and into your system faster than water at room temperature. Fill your bottles halfway and freeze them the night before you ride. Top them off in the morning with cold water.
Now if you're going to be out for more than 90 minutes, a couple of issues arise. First of all, you'll need more water. Time to consider one of the hydration systems like the ones made by Camelback, who originated the category. Basically, these are bladders that you wear over your shoulders like a skinny backpack. They come in various sizes (some hold more than half a gallon) and you can fill them with the beverage of your choice. A flexible straw is routed over your shoulder and clips to your jersey. At the end of the straw is a valve that you operate with your teeth. These systems are available from Performance, Nashbar, or your local bike shop.
Second, you have to start thinking about replacing the electrolytes and minerals you're losing through sweating (like sodium and potassium). You can choose to "Be Like Mike" and use Gatorade or some other sports drink found in the supermarket, or you can mix your own drink using the powders available from health food stores and the bicycle catalogues. It doesn't matter which you choose, as long as it's high in minerals, sodium, potassium and calcium and low in carbohydrates. Why low in carbs? Well, if the concentration of carbs (sugar) in a drink is greater than nine percent of the solution, it will sit in your stomach and wait to be digested. That's why pure fruit juice doesn't work as a sports drink. After the ride, drink and go carb crazy to replace lost muscle glycogen.
Use water, a sport drink and some energy gel for a ride up to three hours. Remember, energy gels or bars pack a lot of carbs, so you'll have to drink more water just to wash them down. Put water in the hydration system, but also keep one bottle of water and one bottle of sports drink on the bike. You wouldn't want to spritz the back of your head or rinse the sweat off your glasses with Cytomax or Gatorade.
All that advice is for the actual ride. You should also start hydrating well before your ride. I mean days before. Eating plenty of fruits and vegetables will provide you with some of the minerals and trace elements you lose through sweating. Running out of these items and water in general can cause your legs to cramp.
Avoid alcohol in the days before you ride -- it has a dehydrating effect on the cells of your body. Skip the java, tea, soda or any other products containing caffeine, which is a diuretic. Diuretics make you pee and that's nothing but wasted water. On the other hand, you should be drinking so much water all the time that you can't stop going to the bathroom. A national cycling team coach once said that if you don't get up at least once a night to go to the bathroom, you haven't had enough water to drink that day.
Finally, there are the little habits you pick up over time. On hot sunny days, I wear light colored jerseys that reflect the sun. Usually they're made of Coolmax or some other wicking material that helps transport the sweat off of my skin so it evaporates more quickly. I like jerseys with long zippers so I can unzip them for a little temporary air conditioning, and I wear a helmet with lots of vents to help with the airflow over my head.
I'm forced to train at high noon during the dog days of summer too, El ... just follow the Camelback slogan: Hydrate or Die!