Martin Gibala is calling your bluff.

The McMaster University kinesiology professor, whose research helped spark a worldwide surge of interest in short, sharp, high-intensity interval workouts, and who co-authored a 2017 book called The One-Minute Workout, has upped the ante yet again. His newest study finds that dashing up a staircase for just 20 seconds, repeated a few times a day, can measurably improve your fitness.

The reason this matters is that “lack of time” often crops up as an excuse when scientists try to figure out why so few of us get as much exercise as we know we should. Gibala and others have been whittling away at this excuse for more than a decade now, designing ever more time-efficient workouts.

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“I certainly don’t think we are going to get much lower in terms of the minimum dose of activity that can yield measurable benefits,” Gibala says of his latest results.

We’re at an important crossroads, then. Either this new workout plan will solve the global inactivity crisis – or we’ll have to rethink our assumptions about what’s really holding us back.

The latest study was led by Madison Jenkins and Leah Nairn, both students of Gibala’s at McMaster, and appears in the journal Applied Physiology, Nutrition, and Metabolism. A dozen sedentary volunteers were instructed to climb three flights of stairs as quickly as possible – a task that took roughly 20 seconds – three times a day with at least an hour between bouts. They repeated this task three times a week for six weeks, and their fitness was then compared to a control group that didn’t do any exercise.

The results showed a significant 5-per-cent increase in aerobic fitness, as measured in an exhaustion test on an exercise bike. That’s about half the size of the improvement seen in some of Gibala’s previous, more time-consuming protocols, so you do pay a price for convenience.

Still, these tiny “exercise snacks,” as the approach is called in the paper, do have benefits. That runs counter to the advice in the Canadian Society for Exercise Physiology’s Physical Activity Guidelines for Adults, which recommend that exercise should be accumulated in bouts of at least 10 minutes. The corresponding U.S. guidelines were revised last November to eliminate the 10-minute minimum, and a CSEP spokesperson said that an update of the Canadian guidelines is currently under way.

So, if the question is: “Do these supermini workouts work if you do them?,” the answer is a qualified yes. Spending 20 seconds on the stairs won’t replace a more rigorous workout, but it’s a decent start.

But if we switch the question to: “Will people – particularly those who don’t already exercise – actually do these supermini workouts, and continue to do them for a long time?,” then the answer is hazier. Critics such as Iowa State University exercise psychologist Panteleimon Ekkekakis have argued that lack of time isn’t really what stops people from exercising, and that the unpleasantness of intense interval training will actually make people less likely to stick with a new workout program.

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“I think it’s true that many people cite time as a barrier, but the reality is they choose to spend their time elsewhere,” Gibala says.

Still, the stair-climbing protocol isn’t just about time, he says. It should also “remind people that ‘exercise’ does not have to involve changing into spandex, going to the gym and making an hour time commitment.” The volunteers in the new study, he notes, didn’t don workout gear or shower afterwards; it was just a brief moment in their normal daily routine.

As for whether people will stick with interval-based training routines – well, some will and some won’t. I’ve been doing interval workouts at least once a week for more than two decades. I like them, but I’ve also come to understand how much some people loathe them.

So, rather than fixating on time efficiency, it’s worth taking an honest look at what’s holding you back from your fitness goals, whether it’s convenience, equipment or simply enjoyment – and finding a routine that works around these barriers. Then get started, even if that just involves heeding the time-worn advice to take the stairs whenever you have a choice.

“The message,” Gibala says, “is start small, and every bit counts.”

Alex Hutchinson is the author of Endure: Mind, Body, and the Curiously Elastic Limits of Human Performance. Follow him on Twitter @sweatscience.

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