Lifting Legs While Running Drains More Energy Than Thought
New finding could lead to improved physical therapies
FRIDAY, Jan. 9, 2004 (HealthDayNews) -- The movement of your legs in the air when you run may consume more energy than you suspect.
Northeastern University researchers say they've demonstrated that, contrary to previous findings, swinging your legs in the air while running requires a significant amount of energy. Previous research concluded the force produced when the foot is on the ground is the only way to determine energy cost when a person runs.
However, the Northeastern researchers found significant energy is used to fuel muscles that move the leg while it is off the ground.
In their study, the researchers estimated energy use by measuring blood flow to the hind leg muscles of guinea fowl. They concluded that movement muscles consume 26 percent of the energy used by limbs while running. Standing muscles consume the remaining 74 percent of the energy.
The study appears in the Jan. 2 issue of Science.
This method of using blood flow to estimate energy consumption offers a technique to provide information about other aspects of energy consumption during running. That could help researchers better understand which specific muscles are used to support weight and how differences in body size and speed affect energy use, which may improve knowledge of rehabilitative medicine.
Here's where you can learn more about physical therapy.