… but make it intense.
From the New York Times:
“One of the main reasons people give” for not exercising is that they don’t have time, says Arnt Erik Tjonna, a postdoctoral fellow at the Norwegian University of Science and Technology, who led the study.
So he and his colleagues decided to slim down the regimen and determine whether a single, strenuous four-minute workout would effectively improve health and fitness.
To do so, they gathered 26 overweight and sedentary but otherwise healthy middle-aged men, determined their baseline endurance and cardiovascular and metabolic health, and randomly assigned them to one of two groups.
Half began a supervised exercise program that reiterated the Norwegian researchers’ former routine. After briefly warming up, these volunteers ran on a treadmill at 90 percent of their maximal heart rate — a tiring pace, says Dr. Tjonna, at which “you cannot talk in full sentences, but can use single words” — for four four-minute intervals, with three minutes of slow walking between, followed by a brief cool-down. The entire session was repeated three times a week for 10 weeks.
The second group, however, completed only one four-minute strenuous run. They, too, exercised three times a week for 10 weeks.
At the end of the program, the men had increased their maximal oxygen uptake, or endurance capacity, by an average of 10 percent or more, with no significant differences in the gains between the two groups.
Metabolic and cardiovascular health likewise had improved in both groups, with almost all of the men now displaying better blood sugar control and blood pressure profiles, whether they had exercised vigorously for 16 minutes per session, or four minutes per session, and despite the fact that few of the men had lost much body fat.