The intensive powers of nutrition

Kristen Reaves, a registered dietitian with Kinesiologists.ca in Vancouver gives clients general guidelines on what to eat, instructing them to cover carbs, protein and fat. The carbs give energy and endurance; protein repairs and builds muscle. And athletes underestimate the importance of heart-healthy fats, she says. "It's been shown over and over how it can help. It's so crucial to maintain mass, stamina, endurance, thinking and memory as well as preventing joint pain," she says.

The carbs, she says, should come from whole grains, vegetables and fruits - complex carbohydrates which stabilize blood sugar and take longer to digest.

Fat takes three to five hours to digest, so it's a no-no just before workouts. A large meal takes four hours to digest.

After a workout, there's a 30- to 35-minute window to get the right nutrients. It's when the body is most able to take in nutrients. If muscles have ripped or torn, the carbs go straight to the muscles as stored energy and protein helps to prep and build up and maintain mass. Gatorade, fruit, a protein shake or a turkey sandwich should do it.