However, in a redshirt year, student athletes may attend classes at the college or university, practice with an athletic team, and dress for play but may not compete in games. Using this mechanism, a student athlete has up to five academic years to use the four years of eligibility, thus becoming a fifth-year senior.
According to the Dietary Guidelines for Americans 2010, sedentary teen girls ages 13 to 18 need about 1,600 to 1,800 calories a day, while sedentary teen boys within the same age range require about 2,000 to 2,400 calories daily to maintain healthy body weights.
According to the USDA, moderately active boys age 9 to 13 need about 1,800 to 2,200 calories per day and moderately active teenage boys ages 14 to 18 require about 2,400 to 2,800 calories each day. Active teenage boys engage in physical activity equivalent to walking more than 3 miles per day.