Using only his or her
available energy stores,
How Far Can a Person Run?
This diagram provides another perspective on energy stores and how long these stores would last if used to fuel continuous activity. Clearly illustrated is the large disparity in running distance when the fuel is based exclusively on carbohydrate stores versus exclusively on fat stores.
Three assumptions have been used to make the diagram:
- The energy cost of running a
mile is 100 calories per mile. Body weight affects the energy cost of movement.
A person who weighs 135 pounds and runs at any pace (5-12 mph) expends approximately
100 calories per mile. A heavier person expends more calories per mile while
a lighter person expends less.
- Each individual substrate is
used as the exclusive energy source to fuel running. In reality, energy
systems are used cooperatively; both anaerobic and aerobic metabolism work
together to provide energy for physical activity.
- The total body store of muscle glycogen is available as fuel for a given activity. Actually, only the muscle glycogen stored in muscles that are contracting can be accessed to fuel a specific activity.
