Humans have had a fascination with their weight throughout the course of history. The perfect weights, ideal weights, and optimal weights of the human body have been the subject of both social and scientific study for centuries.
For non-athletic people, weight is not determined with reference to science or physiology, but by the appearance of the individual. "If you look good, you feel good" is a rule of life for many throughout the world, and these people view ideal weight as one at which they can function as they wish, in terms of the clothing that they may comfortably wear and the daily activities in which they may participate. Ideal weight from a social or personal perspective is unrelated to science.
Sports science approaches weight considerations from a far more rigorous perspective. Ideal weights are not determined with any reference to appearance, but are tied to the analyses of human performance and capabilities achievable at a particular weight to achieve a desired result. The scientifically sanctioned ideal weight for an individual may engage a multitude of physiological, nutritional, training, and competitive considerations, a product of analysis as opposed to personal preference.
Weight gain is a physical process that is diametrically opposed to that of weight loss. These two familiar concepts are positioned on either side of a flexible standard that represents the ideal body weight of an individual. A weight gain strategy is not effective if it later results in the implementation of a corrective weight loss strategy. Western society in general, and North American culture in particular, has been swamped with weight loss strategies in seemingly ever-increasing numbers, with a paradoxical rise in levels of obesity and the numbers of overweight persons; weight gain is a less common concern for the general population.
Weight gain among athletes will be observed in one of three general scenarios: an intentional weight gain, as a part of a structured training and dietary program to achieve a defined athletic goal; a careless or negligent weight gain, when the athlete fails to pay proper attention to diet and nutrition relative to the body's physical demands; and unavoidable or involuntary weight gain, such as those triggered by prescription medication or pregnancy. It is the intentional and the carelessly triggered weight gains that are of prime concern in sports science.
From a scientific perspective, weight gain and weight loss are straightforward scientific propositions. When the attainment of a particular body mass, without reference to physical performance or athletic capability, is the goal of any individual, weight gain or weight loss is readily achievable. One pound of excess body fat represents the storage of 3,500 calories of unused and convertible energy in the body. If a person increases the amount of calories consumed over the amount of energy expended by an amount of 500 calories per day, whether through increased food consumption, decreased physical activity, or a combination of these actions, the individual will gain one pound of body mass per week (7 days × 500 calories), where all other physiological factors remain constant. The same proposition, calculated in reverse, applies to weight loss.
For an athlete, the stark mathematical calculation in support of weight gain is not so straightforward. Ideal weight in any athlete must first be broadly considered with reference to the physical attributes of the athlete with reference to the broader demands of the sport. To reference an extreme example, an 18-year-old female athlete stands 5 ft 6 in tall (1.67 m), and is a strong and fit 135 lb (61 kg). This athlete enjoys throwing the shotput, and wishes to pursue this sport in university competition. An understanding of both the physics of the shotput, and the type of physique needed to compete at a higher level would suggest that the 40-50 lb (20-23 kg) weight gain this athlete would have to achieve to continue with her competitive objectives is likely a physical impossibility. If the athlete wished to be a shot putter for her pleasure, she could do so at her present healthy weight. The ideal weight for this athlete relative to the desired activity is unlikely to be achieved through healthy means.
Once the ideal weight for the specific athlete to compete in the sport has been broadly determined, a number of factors are engaged. The first is the physical composition of the athlete. It is common for persons in the general population and athletes alike to possess a body weight that falls within the apparent ideal range for their participation in a sport. The amount of that ideal weight that is useful lean body mass versus body fat is an important consideration.
The lean body mass is the weight of the musculoskeletal structure; the total mass of an individual less the amount of body fat provides the total musculoskeletal weight. Body fat has been the subject of considerable scientific study. It is generally the fat, stored in the form of triglycerides, that is contained within the specialized adipose tissues of the body; excess fat is simply mass that creates an additional physical demand on the body in the course of athletic performance; leaner bodies tend to be more efficient. The best assessment as to the impact of body fat on performance is to determine the percentage of body fat.
A general tool to predict body fat percentages is the body mass index (BMI). The BMI is a formula that estimates the percentage of body fat in an individual through a consideration of the current height, weight, and age of an individual. The BMI is depicted as a chart that permits people to place themselves accordingly. The BMI is not a determinative measure of body fat.
A more accurate analysis of body fat percentage is achieved through the physical examination of the person. Measurements of the skin folds at the upper arm, abdomen, thighs, and buttocks (the most common storage areas of fat), and submersion in a specially designed water displacement tank will provide accurate measurement of body fat.
The other physiological issues that must be considered in the development of a weight gain strategy are any pertaining to the underlying health of the person. Preexisting conditions, such as diabetes, including prior physical injuries, may influence the manner in which the weight gain program is implemented.
Weight gain will occur whenever the amount of food energy consumed through diet exceeds the amount of physical energy expended. On the simplistic level, an increase in food intake will result in a weight gain. It is the well-managed and carefully directed weight gain program for an athlete that will create a stronger, fitter, more capable athlete. It is for this reason that, once the needs and the person of the athlete has been properly assessed, the diet and the training schedule of the athlete can be coordinated.
Examples of the managed weight gain for a specific athletic purpose are common in elite sports, particularly among athletes seeking to achieve a future professional career. The style of play in the National Football League (NFL) of the United States requires very large and very strong linemen, both in the offensive and defensive formations. Modern football has spawned an evolutionary process at this position, where the offensive linemen are often tall, at heights in a range of 6 ft 4 in to 6 ft 7 in (1.82 m to 1.90 m), with an average weight of over 300 lb (135 kg). The long arms and significant weight permit the linemen to extend their arms to drive back to the somewhat smaller but faster defensive ends; conversely, the most desirable interior defensive linemen outweigh their offensive counterparts, and the defenders seek to secure the lowest possible position and leverage in line play against their opponents.
It is common in NFL football for an aspiring offensive lineman competing at the college level to be encouraged to gain as much as 30 lb (14 kg) in the six months between the end of university football and the commencement of the NFL training camps. Unlike the example of the high school female shot putter, this encouraged weight gain for an athlete 6 ft 4 in and 280 lb (127 kg) is readily achievable. With careful attention to body fat and other efficiency factors, the prospective football player will combine intense resistance training, a moderate amount of cardiovascular conditioning, and balanced diet to manage a weight gain where there is also an increase in his muscle mass.
Careless or unstructured weight gains are often problematic for an athlete. At the conclusion of a long and demanding competitive season, many athletes enjoy a period of deliberate and unfocused rest away from the demands of training. This phenomenon is of particular interest in sports where the athlete competes in a defined weight category. In these circumstances, if the athlete overindulges, consuming food in excess to the regular diet, with a lesser nutritional value, the resumption of training will be hindered by the dual presence of possible nutritional deficiencies and excess weight. Numerous sports scientists and nutritionists advocate that the weight of an athlete who competes in a defined weight class sport should not vary by more than 10% from the ideal competitive weight; these athletes include boxers, lightweight rowers, wrestlers, and many martial arts athletes.
Once an ideal weight has been attained through a healthy and focused weight gain program, it must be maintained at a consistent level. When the athlete no longer competes at either the same competitive level, or on retirement, the basis on which the weight gain was sought will no longer exist. The ideal weight for the athlete will likely be reduced, with appropriate strategy to manage the healthy reduction of body mass to the new desired level.