Scientists out of McMaster University recently conducted research on the shortest interval training ever:
To see just how little you can get away with when it comes to interval training for health purposes, the researchers brought in 25 less-than-in-shape young men (future studies will focus on women). They tested their levels of aerobic fitness and their ability to use insulin in the right way to control blood sugar, and biopsied their muscles to see how well they functioned on a cellular level.
Then they split them into a control group, a moderate-intensity-exercise group, and a sprint interval training (SIT) group.
The control group did nothing differently at all.
The moderate-intensity group did a typical I’m-at-the-gym routine of a two-minute warm-up, 45 minutes on the stationary bike, and a three-minute cool down, three times a week.
The SIT group did the shortest interval training ever recorded thus far by science. Participants warmed up for two minutes on a stationary bike, then sprinted full-out for 20 seconds, then rode for two minutes very slowly. They repeated this twice (for a total of three sets). The whole workout took 10 minutes, with only one minute being high-intensity.
All of the groups kept at it for 12 weeks, or about twice as long as most previous studies.
The results?
The control group, as expected, had no change in results.
The two other groups enjoyed results that were basically identical to each other’s. In both, scientists found a 20 percent increase in cardiovascular endurance, good improvements in insulin resistance, and significant increases in the cells responsible for energy production and oxygen in the muscles (thanks, biopsies).
That is remarkable. By the end, the moderate-intensity group had ridden for 27 hours, while the SIT group had ridden for 6 total hours, just 36 minutes of which was arduous.
This means one group spent about 10 total minutes on each workout, while the other spent 50 minutes. The SIT group got the same benefits in a fifth of the time.