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 17.0 kJ of energy per gram consumed. How many kilograms of protein or carbohydrate must be consumed to provide the energy for 175 minutes of racing that requires 650.0 kcal/hr?

0.467 kilograms of protein or carbohydrates

Explanation:

First, there is a need to understand that 1 kJ = 0.239 kCal

Hence, 17 kJ = 17 x 0.239 = 4.063 kCal

The race requires 650.0 kCal/hr and has to last for 175 minutes.

175 minutes = 175/60 = 2.917 hrs

The total kCal requires for the race = 650 x 2.917 = 1,895.833 kCal

1 g of protein or carbohydrate food produces 17.0 kJ or 4.063 kCal of energy. Hence, the total g of protein or carbohydrate that will produce 1,895.833 kCal of energy would be;

                    1,895.833/4.063 = 466.609 g

1 g = 0.001 kg

466.609 g = 466.609 x 0.001 = 0.467 kg

Hence, 0.467 kilograms of proteins or carbohydrates must be consumed.