Dietary Intake And Energy Expenditure Of Female Swimmers During Decreased Training - Brief Article

Nutrition Research Newsletter, April, 2001

Swimmers, like all athletes, require adequate energy intake for normal daily activities plus the demands of training and competition. Because training volume varies with the competitive season, it is important to investigate dietary intake at different levels of training. Many previous studies have examined the nutritional status of athletes during heavy or peak training. One period of training during which nutritional intake has not been studied is during a taper period, a time of decreased training before an athletic event to improve mental and physical readiness for competition.

A group of researchers chose to look at two important issues related to the nutritional status of competitive swimmers during decreased training prior to competition. One of these issues is whether the discrepancy between energy intake and expenditure previously reported during heavy training is maintained during a period of reduced training. The authors also examined the number of reduced-fat food products consumed by female athletes. Increased use of these foods may contribute to the increased carbohydrate intake observed in some recent studies.

Sixteen women from the swim team of a large Midwestern university participated in this study. All data was collected during a taper phase (swimming 4,300 meters/day, 6 days/week). Training during this period usually consisted of a daily afternoon session lasting 1 1/2 to 2 1/2 hours. Food records were used to collect dietary intake for four consecutive days, including one weekend day. Each subject also recorded vigorous physical activity outside of practice. Total energy expenditure for the four days was estimated by adding the energy costs of swimming and other vigorous physical activity plus sedentary energy expenditure (SEE = energy costs of resting metabolic rate, sleeping metabolic rate, the thermogenic effect of food and light activity).

Mean intakes for carbohydrate and protein were 63% and 14%, respectively, which is within the recommended range. Fat intake was also within the [is less than] 30% recommendation at 23%. Estimated energy intake was 2,275 kcal/day, while energy expenditure was calculated to be 2,341 kcal/day. A subsidiary focus of the study found that all swimmers used reduced-fat foods on a daily basis. Swimmers living off campus tended to consume an average of 3.7 servings daily, while those swimmers living in residence halls consumed an average of 1.6 servings of reduced-fat foods per day.

As was the case in previous studies focusing on intense training periods, a negative energy balance was found during a taper phase, even when underreporting is considered. The results of this research coupled with previous data show that energy intake is not highly associated with a change in training intensity. Levels of athletic training and energy requirements can vary dramatically depending on the season (values were 4,300-19,900 meters/day between taper and peak training seasons). Therefore, it is very important that dietitians working with athletes become familiar with training schedules and educate them on their changing energy and macronutrient requirements.

Laura Ousley-Pahnke, David R. Black, Randall J. Gretebeck, Dietary Intake and Energy Expenditure of Female Collegiate Swimmers During Decreased Training Prior to Competition, JADA 101(3): 351-353 (March 2001) [Address correspondence to: David R. Black, Purdue University, Department of Health, Kinesiology, and Leisure Studies, 1362 Lambert Hall, West Lafayette, IN 47907. E-mail: blackran@gte.net].