Can you eat fast food before a workout?

If you are trying to keep up a healthy, active lifestyle you will want to eliminate fast food from your diet. If you eat it once in a while, as a “treat,” you probably won’t suffer any consequences. If fast food is your regular choice, however, or if you eat it before your workout, you might end up paying the price. Junk food often contains high amounts of sugar, which can directly affect your energy levels. When you eat something full of simple sugars -- like a donut or a piece of candy — it immediately raises your blood sugar.

You will get a quick burst of energy, but an equally quick crash not long afterward. How long the burst of energy lasts depends on your current weight, what you eat and how much. However, if your workout is an hour or two hours long, junk food is not likely to provide you with enough energy.