- One group who exercised little or not at all
- One group that exercised 45-minutes, at a moderate pace on a stationary bike,
- And a third group that did High Intensity Interval Training: two-minute warm-up, then repeated 3 intervals of cycling all-out for 20 seconds followed by gentle pedaling for two minutes. (total workout of 10 minutes and only one minute strenuous exertion)
The exercise groups completed three workout sessions per week for 12 weeks. As reported by The New York Times:
“By the end of the study … the endurance group had ridden for 27 hours, while the interval group had ridden for six hours, with only 36 minutes of that time being strenuous.
But when the scientists retested the men’s aerobic fitness, muscles and blood-sugar control now, they found that the exercisers showed virtually identical gains …
In both groups, endurance had increased by nearly 20 percent, insulin resistance likewise had improved significantly, and there were significant increases in the number and function of certain microscopic structures in the men’s muscles that are related to energy production and oxygen consumption.”
Studies show that working out for very small intervals of time at very hard levels can produce the same fitness benefits as working out longer at lower intensities.