Consider the stroke of a swimmer: The kick of the legs, the pull of the arms and the coordination of both motions with the breath. The energy that fuels each stroke comes predominantly from calories a swimmer gets from food. In addition to the nutrition they require for training, adolescent swimmers have higher energy and nutrient needs than older swimmers. Adolescents are still growing, and growth requires proper nutrition and extra calories.
Active girls ages 9 to 13 require around 1,800 to 2,200 calories per day, while active boys in the same age group require around 2,000 to 2,600 calories per day, according to the "Dietary Guidelines for Americans 2010." Active 14- to 18-year-old girls require around 2,400 calories, while their male counterparts require 2,800 to 3,200 calories per day.
Adolescents who swim daily for an hour or two at practice need more calories than average active adolescents. A two-hour practice adds about 1,200 calories to a swimmers dietary requirements, says registered dietitian Jill Castle at USASwimming.org.
Three macronutrients -- carbohydrate, protein and fat -- provide calories. The USDA recommends that 10 to 30 percent of calories come from protein; 25 to 35 percent from fat; and 45 to 65 percent from carbohydrates. Castle recommends that adolescent swimmers eat three balanced meals and at least two snacks every day to meet their nutritional needs.
Eating for Fuel
During a workout the body uses carbohydrate and fat as its primary source of fuel, and saves protein to use when carbohydrate and fat calories are not available, which can occur when a swimmer does not meet daily caloric needs. An adolescent swimmer needs to incorporate carbohydrate and fat into each meal to provide the body with the proper fuel for both training and growth.
A Balanced Meal
A balanced meal includes a combination of the following foods: whole grains, protein, dairy foods, heart-healthy fats, and fruits and vegetables. Castle urges adolescent swimmers to stay tuned to internal hunger cues, so that they are eating when they are hungry, and to avoid practicing on an empty stomach.
Effects of Deficiency
Adverse effects occur when adolescents do not meet their nutritional needs. Castle says that when nutritional needs are not met, children experience fatigue and lack the ability to build muscle and recover efficiently from workouts. Because the body is not getting the fuel it needs during this growth period, poor nutrition leads to a slowing of physical development and an overall lack of improvement in physical performance.