Sprinters competing in the 2012 Olympics might assume their championship performance is the result of their fuel-efficient physiology.
But a new study disproves the classic scientific view that conserving energy maximizes performance in a sprinting event.
The study by biomechanics researchers Matthew W. Bundle at the University of Montana and Peter G. Weyand at Southern Methodist University, Dallas, demonstrates that metabolic economy is not an important factor for performance in events lasting 60 seconds or less.
In fact, just the opposite is true.
"That prevailing view is no longer viable," said Weyand. "Sprinters, if anything, are wasteful of energy. This is due to the biological trade-offs between faster muscle fibers that provide the large and rapid forces needed for sprinting, and slower muscle fibers that maximize metabolic economy."
Instead, the key to top-flight sprinting is to maximize how hard each foot hits the ground, which allows sprinters to translate musculoskeletal and ground reaction forces into swift motion, said Bundle.
"Saving energy is critically important for endurance, but not for sprinting, which our findings indicate is not energy-limited," Bundle said.
Metabolic energy available from sustainable, aerobic sources predominantly determines performance during endurance events by setting the intensity of the musculoskeletal performance that can be sustained throughout the effort, the study found.
For sprinters, Bundle and Weyand conclude the opposite is true.
"The intensity of the mechanical activity that the musculoskeletal system can (for a very short time) achieve determines the quantities of metabolic energy released and the level of performance attained," according to the study.
The authors reported their findings in "Sprint Exercise Performance: Does Metabolic Power Matter?" in the July issue of Exercise and Sport Sciences Reviews,
|Contact: Margaret Allen|
Southern Methodist University