I don't know if it's a blessing or a curse that I sweat a lot. I've read that fit people sweat sooner. But I recall sweating heavily in gym class in the 3rd grade when I wasn't at all fit. It was actually quite traumatic because one particular girl would always point at my face after class and yell "Ewww! You're really dripping. That is SO gross!" No one else, not even the boys, seemed to "drip" as much as me. Anyway, thanks to wicking headbands and gym hand towels, it's not as noticeable anymore.
However, last year I did notice a change in my performance, especially on certain days when I was teaching two consecutive intense exercise classes. I'd start to feel completely drained mid-class even though I was eating and rehydrating enough. I wondered if depleted electrolytes from heavy sweating were contributing, so for the first time I tried Gatorade (the low calorie G2 version). I used it during class and have to admit that it seemed to do the trick. I haven't had fatigue problems since replacing my regular water with the G2 Gatorade. The only problem is that it's an extra expense and I hate buying bottled waters or drinks because of the environmental waste.
Speaking of waste, when my son Jake recently decided that he only wanted Mader Juicy Juice boxes for school and refused the 8-pack of Fillmore Juicy Juice boxes I'd just bought, I thought it a good excuse to test a homemade sports drink recipe. According to sports nutrition experts, the ideal fluid replacement for vigorous-intensity exercise contains 6-8% carbohydrate (regular Gatorade is 6%) with a small amount of sodium and potassium. According to Vegetarian Sports Nutrition by Larson-Meyer, solutions with 2-8% carbohydrate are ideal because they're digested very quickly and absorbed as well or better than plain water. The electrolytes and sugar help pull water molecules through the intestines. A higher carbohydrate ratio such as in full strength fruit juices or sodas may cause stomach upset or diarrhea.
To make your own, dilute your favorite fruit juice with the same amount of water (e.g., 8 ounces fruit juice and 8 ounces water) to get a 6-7% ratio. You can then add 1/8 teaspoon (290 mg sodium) to 1/4 teaspoon (580 mg sodium) of salt to replete electrolytes. The fruit juice will already contain adequate potassium. I opted to make a 3% carbohydrate drink more similar to G2 with less calories: Mix 3 cups of water with 1 Juicy Juice box and 1/8 teaspoon salt, providing 110 calories in about one liter (920 ml). Add a little Splenda or Stevia if it tastes too tart. It comes out very similar to G2 Gatorade minus the neon colors!