Bodybuilders used to avoid any and all fat in an effort to get ripped. Today, we know that fat is an important nutrient for bodybuilders. Not only does it help to keep testosterone levels high, but the essential omega-3 fats can actually enhance the body’s fat-burning capacity. Ten years ago, the typical bodybuilding diet was composed of only about 10% or less of total daily calories from fat. Today, diets that are 30% fat or higher are common. Despite the necessity of fat in the bodybuilder’s diet, there are still two times of the day when you want to keep fat intake to a bare minimum: pre- and postworkout.
FLEX recommends keeping fat under five grams for your preworkout and postworkout meals, because it can slow down the digestion of protein (which you want to rapidly reach your muscles) and it can blunt blood flow to muscles. Yet, research shows that a third reason has to do with fat’s ability to blunt growth hormone levels. Researchers from the UCLA Medical Center (Torrance, California) had subjects perform 10 minutes of high-intensity cycling on a stationary bicycle under three different conditions. One involved ingesting a noncaloric placebo liquid meal before the exercise test. In another, they took in a liquid meal high in glucose, and in the third, they ingested a liquid meal high in fat. They found that when the subjects consumed the highfat meal before exercise, their GH levels after exercise were cut by more than half of what they were when they consumed the high-carb meal or the no-calorie meal. The researchers discovered that the decrease in GH levels was due to an increase in somatostatin levels. Somatostatin is a hormone that inhibits GH release and is the hormone that arginine blunts, which results in higher GH levels. In a more recent study, these results were repeated by researchers from the University of California Irvine School of Medicine. Based on these findings, you have yet another reason to avoid fat around workout times. If you stick with
FLEX’s standard recommendations: 20 g of whey protein and 40 g of slowdigesting carbs (such as fruit, oatmeal or sweet potatoes) for preworkout and 40 g of whey protein along with 40-100 g of fast-digesting carbs (sports drinks, white bread, sorbet) postworkout, you’ll be able to keep your fat intake around workouts down in order to keep your GH levels up.
BY TABATHA ELLIOTT, PHD
References: J.P. Cappon et al., “Acute effects of high fat and high glucose meals on the
growth hormone response to exercise,” Journal of Clinical Endocrinology and Metabolism,
76(6):1418-22, 1993; P. Galassetti et al., “Effect of a high-fat meal on the growth
hormone response to exercise in children,” Journal of Pediatric Endocrinology and
Metabolism, 19(6):777-86, 2006.