Time is looking like less and less of an excuse to give up on fitness: Following up on the news that you only really need to exercise one day a week to stave off the Grim Reaper, a new meta-analysis in Medicine and Science in Sports and Exercise finds that lower doses of higher-intensity exercise leads to greater fitness.
At least in cycling.
Niels Vollard of the University of Sterling in the U.K. led the meta-analysis, which examined the data from 34 studies on cyclists doing “supramaximal” sprints, which is the way sports scientists describe giving all-out effort. Fitness was measured by VO2 max, or the amount of oxygen that your body can metabolize to fuel your muscles. After crunching the data, the numbers suggest that after two sprints, the fitness benefits start to drop off, with the improvement in VO2 max falling by 5 percent on average per additional sprint.
“For the first time, we have evidence to suggest an indicator of fitness levels is improved more by doing fewer repetitions of high-intensity exercise,” Vollard said in a statement.
More research will need to be done to figure out the minimum viable dose for fitness, he said, but this is welcome evidence that high-intensity, short-duration workouts really do work. They’ll wake your brain up, too.