Ask Jillian Michaels
Q: Is it better to eat a meal before or after a workout?
A: Both. Here's what I like to do: have my breakfast at 9 a.m., work out from 10:30 to 12, and eat by 1 p.m. Here's why:
Back in the old days, people thought they should train on an empty stomach in order to burn more fat, but that has turned out to be FALSE. In fact, your body needs some glucose (blood sugar) for fuel in addition to what it can use from fat stores when you're working out. If you don't have any blood sugar available, your body will eat the muscles' glycogen, or stored glucose. Low blood sugar will also make you tired and sluggish during your training session. For these reasons, I suggest you eat something 45 minutes to an hour before training — you'll have more energy and endurance to work harder, burn more calories, and improve your muscle tone.
After training, during a period known as the golden hour (45 to 60 minutes after a workout), muscles absorb the most nutrients, and glycogen is replaced the most efficiently. You don't have to have a huge meal — just a little something that contains both protein and carbs will give the best results.