One hour of bicycle racing can require 500-900 kcal of energy, depending on the speed of the race, the terrain, and the weight of the racer. Tour de France riders must consume abnormal amounts of food to supply this energy. Food in the form of protein or carbohydrates produces 17 kJ of energy per gram consumed. How many kilograms of protein or carbohydrate must be consumed to provide the energy for 110 minutes of racing that requires 650 kcal/hr.1 kcal = 4.184 kJ.
