Estimate the energy in joules and kcal (food calories) that a runner supplies to overcome aerodynamic drag during a 10 km race. The runner runs a 6:30 pace (i.e., each mile takes 6 minutes and 30 seconds). The product of frontal area and coefficient of drag is CD A = 8 ft ². (One “food calorie” is equivalent to 4186 J.) Assume an air density of 1.22 kg/m³.