by Franz Kelsch

It is very important what you eat and drink during the long period that you will encounter during an event like a double century, especially if the weather is hot.

It has long been known that you need salt during long periods of exercise. See this article below for the research. If you don’t take salt and fluids during extended exercise in hot weather, you will tire earlier and increase your risk for heat stroke, dehydration and cramps.

I have personally found Endurolytes tablets from Hammer Nutrition to work for me and easy to take, without any noticeable side effects. However it is not sufficient to just take these. You also need to hydrate. It takes time for the body to hydrate so you should not wait until you are very thirsty before you start to drink.

When I was doing the Devil Mountain Double last year the hot weather and limited water stops caused me to try to conserve my water intake. It was a big mistake and I ended up with significant cramping, even though I was taking several Endurolytes tables. When I finally reached a rest stop, I had to stay there for a much longer period of time, giving my body time to start to hydrate again.

There were some concerns about over hydrating after the death of some marathon runners who drank too much during the race but the medical experts have now come back around. Read this article on Hyponatremia Should Never Happen to You.

In addition to taking in enough salt and fluids, the next item you need to consider is taking in enough calories. Failure to take in sufficient calories will most likely result in Bonking, or when your body stalls mid-ride.

During the before mentioned Devil Mountain Double, my heart rate monitor said I burned 10,000 calories. A heavier person doing the same ride would have burned even more. Even on a much flatter ride, I burn a significant amount of calories during the ride. If you do not take in enough calories while riding you will bonk. Read these articles on how to prevent bonking during a long ride.

All cyclists have their own solutions for getting in the calories they need. It might be a combination of liquid supplements added to your water bottle, some form of gel, and solid foods. There are conflicting reports in the scientific community on what is the right approach, especially when it comes to the amount of protein that should be consumed. It is important to develop your own approach during training. Don’t try something new when you are doing your first double century. Use what has worked for you on long distance training rides.

The above is only my opinion and the references cited are for information only, and are not intended to diagnose or prescribe. For your specific diagnosis and treatment, consult your doctor or health care provider. See the articles below for additional information.

WHY YOU NEED SALT DURING LONG EXERCISE

Copyright 2007 www.DrMirkin.com.
Used by permission.

Gabe Mirkin, M.D.

During World War II, Dr. James Gamble of Harvard Medical School showed that you have to take huge amounts of salt when you exercise for several hours, particularly in hot weather. Nobody has improved on his research in the last 60 years.

After Gamble published his studies, people who work in the heat were given salt tablets, which is such a concentrated form of salt that it can cause nausea, so some doctors stopped prescribing salt tablets. In the 1960s, doctors became concerned that too much salt can cause high blood pressure, so many doctors stopped recommending heavy salting of food, causing many people to die of heat stroke and dehydration during hot weather work and exercise.

A low-salt diet does not lower high blood pressure in most people with high blood pressure. A high-salt diet causes high blood pressure usually only in people with high blood insulin levels. Heavily salting food and drinking salty drinks when you exercise for more than 2 hours in the heat should not raise blood pressure anyway. If you don't take salt and fluids during extended exercise in hot weather, you will tire earlier and increase your risk for heat stroke, dehydration and cramps.

Schmidt W et al. Plasma-electrolytes in natives to hypoxia after marathon races at different altitudes. Medicine and Science in Sport and Exercise. 1999 (October);31(10):1406-13

BONKING

Copyright 2007 www.DrMirkin.com.
Used by permission.

Gabe Mirkin, M.D.

If you watch a major bicycle race on TV, you have to be impressed by how the riders can eat enough to sustain them through races that require more than five hours of near maximum effort. If they do not get enough food during their ride, they can fall off their bikes, lie on the ground unconscious and start to shake all over in a in a massive convulsion. This is called bonking: passing out from low blood sugar.

Your brain gets almost all of its fuel from sugar in your bloodstream. When your blood sugar level drops, your brain cannot get enough fuel to function properly, you feel tired and confused and can pass out. There is only enough sugar in your bloodstream to last three minutes. To keep your blood sugar level from dropping, your liver must constantly release sugar from its cells into your bloodstream, but there is only enough sugar in your liver to last 12 hours at rest. During intense exercise, your muscles draw sugar from your bloodstream at a rapid rate. Your liver can run out of its stored sugar and your blood sugar level can drop, and you bonk.

Bonking is common in bicycle races if a rider does not eat frequently, but is rare in long distance running races. When you run, your leg muscles are damaged from the constant pounding on the roads and you must slow down. However, you pedal in a smooth rotary motion which does not damage your muscles, so you can continue to pedal at a rapid cadence for many hours.

To prevent your blood sugar from dropping too low during intense exercise lasting more than two hours, eat at least every 15 minutes. It doesn't matter what you eat: salted peanuts, a peanut butter and jelly sandwich, chicken, an apple, a banana or anything else. Almost all fit people can take small amounts of food frequently during exercise without developing stomach cramps.

THE SCIENCE BEHIND BONKING

Also read this article from Runner's World magazine on bonking.