Wed, May 17, 2017 | by TJ JuskiewiczShare
Hydration is an important consideration when riding a bicycle across Iowa in what is often one of the hottest weeks of the year! Your body is continually losing moisture through perspiration, respiration and urination. We must continually replace this lost fluid to maintain proper functioning of our body. 60% of the human adult body is water while the brain and heart are composed of 73% water, and the lungs are about 83% water. The brain, heart and lungs are important, especially for cycling. When we sweat we lose not only water but also electrolytes. Electrolytes are minerals that are critical for the functioning of the body’s many reactions. The major ones are sodium, calcium, potassium and magnesium. So when replacing fluid we also need to replace electrolytes.
We are sweating all the time although at certain times it is more apparent than others. Ride a bike in blazing sunshine during 90 degree weather and 90% humidity and you will be dripping wet. But you also sweat a lot on dry days when you don’t feel sweaty, you just don’t notice it because your sweat dries so quickly. Sweating cools the skin when it evaporates. This is why dry air (think Colorado) feels so much fresher and cooler than Mississippi (or Iowa) in the summertime. The point is, you are losing a lot of moisture when you ride a bike, whether you realize it or not. To illustrate this point, weigh yourself before and again after a ride. It isn’t uncommon to lose 2-3 pounds on a bike ride. And this doesn’t even include the water you drank during the ride.
It is difficult to come up rules of thumb about how much to drink while exercising because all conditions are different, such as temperature, humidity, effort level and individual sweat rate differences. But first of all, it’s important to begin a ride fully hydrated. You should have had to use a restroom (or porta potty) just before your ride. This indicates your fluid levels are topped off. Your thirst mechanism is good but it is not proactive. It doesn’t know you are going to be riding for the next 8 hours on RAGBRAI. So start sipping from your water bottle before you start feeling thirsty (drink before you are dry). This is especially important on very hot days because if you get behind in re-hydrating, it can be difficult to catch back up. You should aim to drink at least one large water bottle per hour, and 2-3 when it is really hot.
But don’t just focus on water. You also need to replace electrolytes. Most people think about salt but sodium isn’t enough. You also need the other electrolytes as well. If you eat a balanced healthy diet, you probably get what you need, but when you are sweating heavily you may run low on some of these. Sports drinks, such as Gatorade and numerous powered products, contain electrolytes as well as water and sugar. So you might want to add sports drinks while riding on hot days. I don’t recommending taking salt tablets because these just replace sodium. Instead there are electrolyte tablets you can purchase to supplement with all the necessary electrolytes.
You also want to be aware that it is possible to drink too much water as well. There is a condition called hyponatremia where you drink so much that you dilute your sodium balance in your body, you literally drown yourself. Now this is a rare event and typically is only seen in extreme sport situations, but for some people, doing RAGBRAI is pretty extreme. This is another reason why you shouldn’t drink just water but include electrolytes.
Bottom line – Be conscious about staying hydrated and don’t just rely on thirst, and include electrolytes as well as water.
Coach David Ertl
David Ertl is a USA Cycling Level 1 Coach. He coaches the Des Moines Cycle Club Race Team, JDRF Ride To Cure Diabetes and individual cyclists through the Peaks Coaching Group. He also provides cycling training plans and ebooks at his website: http://www.CyclesportCoaching.com . He can be contacted at email@example.com.