Fuel During Exercise

The rule of thumb that I live by is that if you are doing less than 60 minutes of cardio (or weights for that matter) you do not need anything but water to hydrate. You do not need a sports drink with sugar for that short duration of exercise. If you do like the taste of a sports drink and you want to drink it even though you are doing less than 60 minutes, that is fine and you may even get a little bit better performance from it. However, if you are trying to lose weight or prevent weight gain and are relying on burning those calories in your session of exercise, you do not need to drink them right back on with a sports drink!

You do need water, so drink 4-8 ounces every 15-20 minutes during exercise. If you choose to drink a sports drink, that will hydrate you and counts as your water (you don't need 8 ounces of both, but you could do a little of each if you want).

That being said….there are occasions when you may need something with sugar, or calories, to keep you going. Again, the rule of thumb is if you are going an hour or more, then you will need some sugar to get you to the finish.

What should you eat/drink?

You want high glycemic index carbs during exercise. High GI carbs will be absorbed quickly into the bloodstream so you can use them right away. Examples: Sports drinks, sports gels, jelly beans, gummy candy, pretzels, bananas, diluted juice, honey sticks, etc. I personally stick with sports drinks and gels because they are easy, fairly tasty, and convenient. I can tuck a gel into my shorts or plant some sports drink on my route.

How much do you need?

You need about 30-60 grams of carb per hour of endurance cardiovascular exercise. Read labels of the particular brand you are using, but most sports drinks have about 15 grams per 8 fl oz (1 cup) serving.

Just because you don’t need it if you do less than one hour of exercise doesn’t mean that you should start at one hour into exercise to get sugar. If you are going for a long endurance session, start at 15-20 minutes into it with the sugar containing fluids or foods so that you don’t crash when you get to one hour. Continue all the way through and after your exercise is finished.

Things to consider:

1. When you are exercising, your body is finicky with what it will accept. Gastrointestinal (GI) upset (aka diarrhea) is very common among athletes if they eat the wrong things (even if they eat the right things!)
2. Sports drinks are formulated with the exact percentage of carbohydrate that is absorbed properly with minimal GI upset. If you drink full strength juice instead of sports drink, you may experience serious cramping and diarrhea.
3. If you choose to use gels or jelly beans or candy, make sure you drink water with it to help with absorption and to dilute the amount of sugar coming in.