Bodybuilding

Bodybuilders strive for a physique that is the extreme of high muscle mass and low body fat. The low body fat is a necessary adjunct to performance, which requires a high level of muscular definition to achieve a high score. A high body fat level would mask the underlying muscle formation because approximately 50 percent of all body fat expresses itself subcutaneously. To achieve this high level of muscle mass, bodybuilders must place a high level of repetitive stress (typically via free weights and muscle-resistance equipment) on each muscle group. This is never done aerobically (i.e., low-level muscular force over long time periods). Instead, bodybuilders rely on high-intensity repetitions that rarely last longer than 30 seconds per muscle group and never last longer than 1.5 minutes. In preparation for competition, bodybuilders couple this hard muscle training with the consumption of extra energy to support an enlargement of the muscle mass or reduction of the fat mass.⁹ Diets of body builders are often high in protein and protein-related supplements and creatine.¹⁰

Once the muscle mass is enlarged, bodybuilders go into a second training phase that involves a reduction in energy coupled with a small aerobic component in the training.¹¹ This second phase is aimed at reducing body fat levels (particularly subcutaneous fat) to allow for a greater visual muscle definition. During the week before competition, bodybuilders typically decrease total energy intake and increase carbohydrate intake to glycogen load the muscles. There is also a great deal of fluid and sodium manipulation to aid in muscle definition. During this week, both fluids and sodium are typically restricted. There is evidence that fluid restriction is dangerous, particularly in younger bodybuilders, where both low blood potassium and phosphorus have been observed.¹² There is also evidence that the energy restriction common during the period immediately before the competition causes a loss of lean body (muscle) mass, suggesting that the energy restriction is counterproductive.¹³

Perhaps no sport is as prone to nutrition misinformation as bodybuilding. In a study evaluating advertisements in bodybuilding magazines, no scientific evidence was offered for 42 percent of the products for which beneficial nutrition claims were made. Only 21 percent of the advertised products had appropriate documentation to support their claims, and 32 percent of the products that had some scientific documentation were marketed in a misleading manner.¹⁴ A study of male and female bodybuilders found widespread multidrug abuse (up to 40 percent of the subjects), and a majority of bodybuilders reported following regimens that led to severe dehydration.¹⁵ In this same study, the female bodybuilders had extremely low calcium intakes and nutrition practices that placed them, as a group, at high risk for poor health. Keeping this in mind, bodybuilders must consider the following nutritionally relevant factors for their sport.

Bodybuilders strive for a high level of muscle mass, a goal that mandates a higher need for energy. Although the total amount of protein needed to maintain this larger mass is slightly greater than what athletes with a stable muscle mass require, the proportion of protein provided by typically consumed foods is likely to satisfy need. Ideally, bodybuilders should consume between 1.5 and 1.7 grams of protein per kilogram of body weight, but this should be consumed in the context of adequate total energy consumption where most of the energy is derived from carbohydrates.

Studies of bodybuilders strongly suggest that protein consumption is usually much higher than the body's capacity to use it anabolically (i.e., to use it to build tissue). Therefore, the excess protein is simply burned as a fuel or, in the case of excess total energy consumption, stored as fat. This has been confirmed by the findings in one study, which determined that bodybuilders had significantly higher protein intakes than did lean control subjects, and they also relied more heavily on protein as a fuel to meet the energy requirements of the muscles.¹⁶ The belief that the excess protein is a requirement for building muscle is pervasive among bodybuilders, but in truth, this extra protein is merely a source of needed calories that would be more efficiently provided through the non-nitrogenous energy substrates. The key to building muscle mass is to consume enough energy to support the larger mass. A bodybuilder now weighing 180 pounds (82 kilograms) who wishes to weigh 190 pounds (86 kilograms) should eat enough energy to support the larger mass. In doing so, the increase in calories should not come solely from protein but rather a proportionate increase in protein, carbohydrate, and fat where carbohydrates remain the major source of energy. Data from successful bodybuilders suggest that the ideal composition of diets should emphasize carbohydrates (55 to 60 percent of intake) and be relatively low in fat (15 to 20 percent of intake), with the remainder from protein (25 to 30 percent of intake).¹⁷

Bodybuilders strive for an extremely low level of fat mass. Body fat percentage is, to a great degree, determined by a person's genetic makeup but can also be influenced by dietary and exercise habits. From a dietary standpoint, it is most important to consume only enough energy to meet physiological need because excess energy intake will manifest itself as stored fat. Dietary fat is the most concentrated source of energy, so consumption of excess fat may most easily create an excess total energy intake, and it is easily converted to stored fat. Carbohydrates are more efficiently burned as a fuel for high-intensity muscular work and are not as efficiently converted to fat for storage. For these reasons, fat intake should be kept relatively low (15 to 25 percent of total calories). This level of intake is slightly below the general population recommendation that no more than 30 percent of total calories be provided from fat. The consumption of small and frequent meals is also a useful strategy because it helps suppress the manufacture of fat by lowering the insulin response to food. If you eat 1,500 calories in a single meal, the normal processing of so much energy at one time will inevitably lead to an important percentage of this intake being stored as fat. Were this 1,500-calorie meal to be consumed in two meals that are 3 hours apart (750 calories per meal), the energy could be more effectively processed without storing a significant proportion of it as fat. Therefore, eating the right amount of calories to maintain an energy-balanced state (something that is easier on a moderately low-fat diet) and eating small but frequent meals are both important strategies for obtaining a low body fat percentage.

Bodybuilders commonly go through repetitive patterns of weight gain and weight loss in an attempt to build muscle and then reduce body fat levels. The average reported weight loss experienced during the competitive season is 15 pounds (6.8 kilograms), and the average reported weight gain is 14 pounds (6.3 kilograms). This cyclic dieting leaves bodybuilders with a food preoccupation that leads to binge eating after competitions, as well as psychological stress.¹⁸ A much more logical approach to building muscle safely is to consume a moderate excess in calories (300 to 500 calories beyond current needs) from complex carbohydrate to support a larger muscle mass, coupled with activities that sufficiently stress the muscles to encourage their enlargement.

Bodybuilders appear to be excessively dependent on nutritional and quasi-nutritional products and ergogenic aids to achieve the desired body composition. Self-experimentation with ergogenic aids and nutritional products is common in many sports. However, bodybuilders are especially targeted by marketing efforts for these products. To make matters more complex, the placebo effect in nutrition is very real. That is, if an athlete believes a product will help him or her meet specific goals, then it probably will have some benefit even if there is no physiological or biological basis for this improvement. Ideally, athletes should consume products and foods that have a physiological and biological basis for achieving their goals. If the athletes also believe these products and foods work, they may realize an even greater benefit (i.e., the placebo effect).

It is common for bodybuilders to rely on strategies that increase body water loss to achieve the desired cut appearance. Dehydration is dangerous (numerous deaths occur yearly from dehydration, among both athletes and nonathletes) and diminishes athletic performance. With bodybuilders, even though it is important to have a "ut-appearance, achieving this through dehydration is an unacceptable strategy because it can lead to organ failure and death. Bodybuilders should achieve their desired appearance through hard work and the development of a relatively low level of body fat using the strategies discussed already.

Nutrient intake appears to be inadequate for many in this population. The focus on nutritional products (protein powders and shakes, amino acid supplements, creatine monohydrate supplements, and so on) rather than nutrient-rich foods may place bodybuilders at nutrition risk. Consumption of low-fat, high-carbohydrate, moderate-protein foods that provide adequate energy (calories) will ensure a good nutrient intake. An excessive reliance on supplements appears to provide an unnecessarily high protein intake and may not satisfy the nutrients most lacking in the diets of these athletes. Blindly consuming individual vitamin and mineral supplements is also not a useful strategy because athletes rarely know what specific nutrients are most needed. Consumption of a wide spectrum of foods that exposes these athletes to all the nutrients is the best strategy, with supplements playing a role only where the adequate intake of energy substrates or nutrients is impossible.