Given the recommendation that total daily caloric intake should consist of no more than 30% fat, and that the average diet contains a significantly greater percentage, much of the perils attributed to fat can be charged to excessive fat consumption. In fact, most recommendations made by nutritionists suggest that a safer fat intake would be approximately 20-25% of total calories. Of this amount, roughly two-thirds should be comprised of unsaturated fatty acids, with saturated fats making up the final one­third.

In most cases, athletes and lay people alike consume more fat than is required. From an athletic standpoint, it may be that fat intake is not of dire concern if carbohydrate needs are met and adequate glycogen stores are maintained. Furthermore, the energy that can be derived from triglycerides in stored adipose tissue is sufficient for nearly interminable periods of moderately intense exercise. For the most part, therefore, as long as carbohydrate and protein ratios are met, athletes should allow fats to make up the remaining percentage. For example, because carbohydrates will typically make up roughly 60% of total calories and protein, 15-20%, fats would comprise the aforementioned 20-25% of total energy.

Although ample amounts of energy are stored as fat, the relative contribution of fat to energy production is limited by the delay in which it can be mobilized and ultimately oxidized. In the case of high-intensity exercise, this delay is increased and fat oxidation can eventually become unattainable. That is, as exercise intensity increases, the contribution of fat towards energy production decreases. Because low-intensity training uses a greater percentage of fat than does high-intensity exercise, it would appear that fat intake is a significant concern for endurance athletes. However, many endurance competitors can maintain an exercise intensity level that still derives a majority of energy from glycogen, thus reducing the importance of fats. Even in the occurrence of ultra-endurance events (i.e., triathlons, ultra marathons), in which fat metabolism increases in significance, the near endless supply of stored fats makes the need for further supplementation unnecessary.

The significance of proper fat intake for the high­intensity sporting athlete is found in the fact that fatty acids are continually oxidized to provide energy for muscular function, although the contribution of fat is minimal during exercise itself. For this athlete, it is between repeated high-intensity exercise bouts when benefits are derived from fat oxidation and adequate intake. For example, the enormous caloric expenditure that results from repeated sprints means that increased fat will be oxidized at rest and during low-intensity phases of training. Although performance benefits are doubtful following fat supplementation, inadequate fat intake (less than 15-20% of total calories) has the potential to hinder performance. Such is the case for both endurance and high-intensity athletes.

Those individuals who are severely limiting fat intake (less than 10% of calories) run the risk of becoming deficient in essential fatty acids, particularly linoleic acid. This may jeopardize health in the long-term, especially because this practice may also cause deficiencies in fat­soluble vitamins. Many athletes and exercise enthusiasts restrict fat intake for physique-related reasons, and this practice is also discouraged, given that total calories are much more significant in reaching body composition goals. Severely restricting fat intake, has the potential to limit subsequent fat mobilization and oxidation. Of course, this is highly undesirable for those individuals who want to lose fat.


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