Typical fats contain about 9 kcal per gram. If the energy in...

Typical fats contain about 9 kcal per gram. If the energy in body fat could be utilized with $100 \%$ efficiency, how much mass would a runner lose in a 26.2 -mile marathon while consuming 125 kcal/mile?

Labs

Want to see this concept in action?

NEW

Explore this concept interactively to see how it behaves as you change inputs.

View Labs

Key Concepts

Energy Density of Fats

This concept refers to the amount of energy stored in a unit mass of fat, which is typically about 9 kilocalories per gram. It serves as the conversion factor to determine how much physical mass is associated with a specific amount of energy, and it is essential for understanding the energy yield from metabolizing body fat during physical activities.

Caloric Expenditure Calculation

This concept involves determining the total energy used during an activity by multiplying the per-unit energy cost (in kcal per mile) by the total distance traveled. In contexts like a marathon, calculating the cumulative caloric burn helps quantify the overall energy deficit that must be compensated for, which is crucial for estimating changes in body mass.

Conversion of Energy to Mass Loss

This concept is the application of converting the calculated total energy expenditure into the corresponding mass change. By dividing the total energy deficit by the energy density (kcal per gram) of fat, one can estimate the amount of fat mass that would be lost if the energy were derived solely from fat reserves. It is a practical illustration of how energy-conservation principles can be used to relate energy consumption to physical changes in mass during exercise.

Transcript

Please give Ace some feedback