Runners work nearly 30 percent harder on curved, non-motorized treadmills than on traditionally flat, motorized models, according to a study published in the Journal of Science and Medicine in Sport.
For "The Physiological and Perceptual Demands of Running on a Curved Non-Motorised Treadmill," researchers from the University of Essex School of Sport, Rehabilitation and Exercise Science studied 13 elite male runners across three varied tests. (The participants qualified for the study by their ability to run three miles in 20 minutes or less.)
The first test required participants to run to exhaustion on a motorized treadmill with a 1 percent gradient. During the test, the researchers measured each runner's maximum heart rate, oxygen uptake and running velocity.
A second test required participants to run on a curved treadmill at five different velocities—40 to 80 percent of their previously measured maximum velocity—with a three-minute rest between intervals.
A third test asked participants to complete the same intervals as the second test but on a flat motorized treadmill. The participants were also required to report their perceived effort at this time.
In conclusion, the participants perceived themselves to be working 27 percent harder when running on a curved treadmill. The researchers' data reinforced the runners' perceptions.
On curved treadmills, the participants consumed 32 percent more oxygen, displayed 38 percent worse running efficiency, reported a 16 percent higher heart rate and a 2.5 percent greater running cadence.
Study author Patrick Schoenmakers, research fellow at the University of Essex, said that curved treadmills uniquely respond to runners in a way that traditionally motorized treadmills do not.
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