This may come as a surprise, but most athletes don’t eat enough. At SPARTA, we are constantly telling new athletes that they need to eat more, and especially more frequently. The prevalence of eating disorders in athletes (especially females) is well documented. In a study of 263 athletes and 263 non-athletes in the Department of Psychology at the University of Western Australia, the athletes had a higher percentage of eating disorders than the non-athletes. Sports that stressed a thin body shape (diving and gymnastics), or a low body weight (rowing, cycling), were especially prone to eating disorders. Eating disorders aside, the idea that physical shape is the best indicator of fitness is a concept that leads many athletes to a detrimental eating pattern.
Most athletes feel that the best way to maintain the body weight they want is to eat less, and especially eat less fat. This leads to skipping meals (especially breakfast) and a diet that is too high in carbohydrate and deficient in fats and protein. The Department of Physical Therapy, Exercise and Nutrition Sciences at the University of Buffalo has done extensive research on the effects of acute exercise combined with inadequate nutrition. In their estimation, many athletes consume about 25% fewer calories than they expend, leading to low intake of essential micronutrients and fats. Intense exercise has been shown to increase inflammatory immune factors (weaken your immune system), increase oxidant stress (those pesky free radicals everyone is always talking about), and increase stress hormone levels. Low nutrient levels, specifically low glycogen (sugar) and fat stores are shown to have the same effect, compounding the problem. When your body is put in a stressed state, either through intense exercise or deficient nutrition (or both), performance suffers and the risk for infection rises dramatically.
So how can you combat the effects of acute exercise? The researchers at the University of Buffalo showed that most athletes’ diets are too low in fat, and too high in carbohydrate (roughly 15% and 65% respectively). This macronutrient combination decreased anti-inflammatory immune factors, depressed antioxidants and negatively effects fat and protein ratios in the blood. Conversely, athletes with a 25% higher caloric intake (which matched energy expenditure), including 32% of calories from fat, reversed the negative effects of the low-fat, high-carbohydrate diet. In addition, this higher fat diet had no negative effect on performance, and in fact increased endurance performance at 60-80% of VO2max in cyclists and runners. This increase in endurance performance can be attributed to glycogen sparing, in which glycogen (sugar) stores in the body are maintained by increased fat oxidation (using fat for energy instead of sugar). Muscle glycogen depletion compromises exercise performance and increases stress factors.
Athletes can combat the effects of acute exercise by consuming at least as many calories as they expend. Eating frequently (this means breakfast and snacks) will keep glycogen stores high and immune stress low. In addition, a higher fat diet can help reduce the inflammation associated with intense exercise, and help protect vital glycogen stores. Skipping meals is not a good way to control body composition in sports where body weight is a factor. The increased stress from poor nutrition can actually lead to a slowed metabolism, and breaking down muscle for vital nutrients, decreasing the energy levels and strength necessary for elite performance. Diets containing the right combination of protein, fats and carbohydrate can effectively control body weight, while maintaining the high energy levels needed for athletes.