Sport Performance and Metabolic Rate

The following is an exclusive excerpt from the book NSCA's Guide to Tests and Assessments, published by Human Kinetics. All text and images provided by Human Kinetics.

Knowledge of metabolic rate can help athletes as well as health-conscious people improve their exercise performance or obtain the fat-to-lean-mass ratio optimal for their personal situations. Metabolic knowledge can be used to create a personal training plan, to design an eating schedule for an ultra-endurance event, to monitor body composition during the off-season, and to lose weight to improve health status; it can also be applied to other needs. Two examples of how this works follow.

A personal trainer, who is also a dietitian, is working with an athlete who wants to increase lean body mass during the off-season. The professional obviously knows how to structure the off-season training regimen and how to design a diet to meet specific nutritional needs. What the professional will need to know to make this program most effective is the client’s metabolic rate—specifically, the client’s 24-hour energy expenditure. Because this client is an athlete who expends a great deal of energy when training, the professional will need to determine the athlete’s exercise energy expenditure as well as the resting energy expenditure to calculate the athlete’s 24-hour energy expenditure. If the athlete’s RMR is 2,300 kcal per day, and the athlete will expend an additional 700 kcal a day in exercise, the athlete’s 24-hour energy expenditure would be 3,000 kcal per day. The personal trainer would then have to design a nutritional plan for the athlete that surpasses 3,000 kcal per day for the athlete to increase lean body mass.

A second example is of a competitive cyclist planning to compete in an ultra-endurance event lasting several days (e.g., the Tour de France). The goal for the dietary prescription during the event is to ensure adequate energy intake to meet the metabolic demands of the competition. Otherwise, the athlete will become fatigued prematurely. Again, knowing the athlete’s 24-hour energy expenditure is critical to the design of the diet plan. If the athlete’s RMR is 2,000 kcal per day, and the athlete expends an additional 6,000 kcal per day in activity, the goal would be to consume 8,000 kcal per day during the event. Knowing this, the professional can now structure the composition of the diet and the timing of dietary intake to match the exercise needs and meet the 8,000-kcal-per-day requirement.

In the two preceding examples, accurate measures of RMR and exercise energy expenditure were necessary prior to the design and implementation of a diet and exercise regimen. There are several ways to measure energy expenditure. The method of choice will depend on equipment availability, cost, and desired accuracy.

Developed by the National Strength and Conditioning Association (NSCA), this comprehensive text offers extensive information on performance-related assessment and testing for strength and conditioning professionals in measuring key fitness components. The book is available in bookstores everywhere, as well as online at the NSCA Store.