Team-sport athletes ( 9 male , age 22.3 2.1 y , VO2max 57.4 8.5 mL kg-1 min-1 ; 7 female , age 20.7 1.3 y , VO2max 47.2 8.5 mL kg-1 min-1 ) were assigned to a double-blind , randomized , crossover design .