Outside takes a hard, scientific look at our pandemic year (and our softening middle sections) using a measure called “VO2,” which is a way of tracking how aerobically fit one is. Experiments have found that if you want to keep fit when you can’t work out as often, then keeping your workouts long and intense is key:
The overall conclusion of the new review, then, is that you can get away with as few as two sessions a week as long as you maintain volume and intensity of your workouts. But they caution that maintaining your VO2 max isn’t the same as maintaining your ability to perform long-duration endurance activities. Don’t expect to run your best marathon after a few months of twice-a-week training: your legs, if nothing else, won’t be able to handle it.
The picture was similar when Hickson’s volunteers reduced the duration of their training sessions to 13 or 26 minutes (i.e. reducing their baseline duration by one third or two thirds). Once again, VO2 max gains were preserved for 15 weeks. This study also included tests of short (~5-minute) and long (~2-hour) endurance. Short endurance was preserved in both groups, but the 13-minute group got worse in the two-hour test.
The third and final variable that Hickson manipulated was intensity—and here, finally, we get confirmation that training does matter. Dropping training intensity by a third (from 90 to 100 percent of max heart rate to 82-87 percent) led to declines in VO2 max and long endurance; dropping it by two-thirds (to 61 to 67 percent) wiped out most of the training gains. The takeaway: you can get away with training less often, or for shorter durations, but not with going easy.
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One of the co-authors of the new review is Iñigo Mujika, a physiologist and coach at the University of the Basque Country in Spain who is among the world’s leading experts in tapering, in which athletes try to reduce their training enough to rest and recover for a few weeks without losing fitness before a big race. In tapering studies, athletes can reduce their training frequency by about 20 percent and their volume by 60 to 90 percent and maintain fitness as long as they keep their intensity high. That’s one good reality-check that suggests [Robert] Hickson’s findings [from the 1980s] about the importance of intensity make sense.