Your choice of preworkout carb can have a huge effect on your next training session

June 16, 2011


You know what 20/20 vision means in terms of eyesight. Here at FLEX, we aim for 20/40–as it relates to preworkout nutrition. By that, we mean you should consume 20 grams of protein, such as whey, and about 40 g of slow-digesting carbs in the form of whole-wheat bread or oatmeal, for example, before you train. Why? Slow-digesting carbs will keep insulin levels low, which will help you burn more fat during exercise and have longer-lasting energy. Getting in a fast-digesting protein, such as whey, before workouts will help to prevent muscle breakdown during the workout and boost protein synthesis as soon as the workout is over. Don’t just take our word for it.

THE STUDY: The National Taiwan College of Physical Education had eight male athletes run to exhaustion on two separate occasions. During one session, they ran three hours after eating a meal that was rich in slow-digesting carbs (Kellogg’s All-Bran cereal, skim milk, peaches, apples and apple juice). During the other session, they ran three hours after consuming a meal of fast-digesting carbs (Kellogg’s Corn Flakes, skim milk, white bread, jam, a glucose drink and water).

THE RESULTS: As reported in the International Journal of Sport Nutrition and Exercise Metabolism, the subjects were able to run almost seven-and-a-half minutes longer after eating the slow-digesting carbs, compared to having the fast-digesting carbs preworkout. The reason? The runners burned more fat for fuel during the run when they ate slow-digesting carbs.

THE MORAL: Choose your preworkout carbs wisely. Make sure they are slow-digesting carbs such as fruit, whole-grain breads, pastas, oatmeal and sweet potatoes. This will help you keep energy levels maximized throughout the entire workout, as well as enhance your fat-burning potential. Save the fast-digesting carbohydrates–such as sports drinks–for after the workout.