If You’re Doing Heavy Lifting, Eating After Exercise is Important

The exception to exercising while fasting is if you’re doing heavy lifting. In that case, it’s important to eat within 30 minutes afteryour workout, and your meal should include fast-assimilating protein. Whey protein is a useful option here. Furthermore, some people do have a hard time exercising without eating something first, and for these people whey protein can also be a beneficial pre-workout meal.

Typically these people are more sensitive to changes in their blood sugar levels, which can decline during the first 15-25 minutes of their workout. It is this decline in blood sugar that causes dizziness, faintness, nausea or lightheadedness. This is especially true if you exercise first thing in the morning.

Of course, a number of individual factors can also play a role in whether it's appropriate to exercise while fasting, such as your age, when you last ate, whether or not you're pregnant, taking medications, your medical history, level of fitness, and the type of workout you engage in. I have also been playing with having some fruit immediately prior to lifting. You will easily burn it during the workout so it should not impair insulin sensitivity and it also provides you with some more fuel to work out harder. I typically have a serving of whey protein 30 minutes after a strength workout.