It's officially summer. Even though the temperatures are lower than average for this time of year, the humidity today is 100%. The heat index provides warnings for weather conditions that will make heat stroke more likely. In short, the body experiences 88-degrees/85 percent humidity as if it were 110 degrees. At 40 percent humidity or lower, 88 degrees feels like 88 degrees. So even though the temperature is lower, the need to hydrate is greater. While everyone agrees that it’s critical to stay hydrated, not everyone agrees on how to stay hydrated.
For instance, does coffee/caffeine actually cause dehydration? If I drink 2 cups of coffee prior to a 3 mile run, am I actually doing myself harm?
Or what if I hop on my bike and pedal down to the lake and back? The entire trip takes nearly 60 minutes, and I’m drenched by the time I’m finished. Should I rehydrate with a sports drink?
Let’s start with coffee. Current research out of the Mayo Clinic indicates that if you consume more than 4 to 7 cups of coffee daily, caffeine may have a diuretic effect. If you drink more than 7 cups of coffee in a day without any other liquids, you may become dehydrated from not enough liquid in your body to function normally. Furthermore, in a study published in the Journal of the American College of Nutrition, researchers looked at how different combinations of water, coffee, and caffeinated colas affected hydration levels in a group of 18 men between the ages of 24 and 39. During one phase of the experiment, the only fluid the volunteers consumed was water. During another, 75% of their intake was caffeinated. Although researchers used “almost every test ever devised to measure dehydration”, they found no difference at all.” Whew. Coffee can stay. YAY!
Moving on to sports drinks. Most researchers agree that the only folks who actually need sports drinks are ATHLETES. So, unless you’re exercising at a high intensity for 60 minutes or more (think marathon, triathlon, etc), it's really not necessary to replace losses of sodium, potassium and other electrolytes during exercise. Looks like I’ll be enjoying a tall glass of water at the end of my ride!