For those of us who enjoy exercise, sometimes we don’t have time to make a meal out of it. Sometimes, an “exercise snack” has to suffice.
For those who say a lack of time means they never make a meal out of it – about 40 per cent of Australian adults – these “snacks” are a way to start sneaking the benefits of exercise into their day.
The question for researchers trying to tackle the lack of time excuse, and help the 60 per cent of adults who don't move enough, is how small a snack will satiate our body’s exercise needs?
The Canadian researchers who brought us the six-minute workout and then the one-minute workout, have found that a 20-second exercise “snack” done several times a day leads to measurable health and fitness benefits.
For the study, published in the journal Applied Physiology, Nutrition, and Metabolism, 12 sedentary students were asked to sprint a 60-step flight of stairs – a task that took about 20 seconds – three times a day, with one to four hours' break between each set. Before each set, they did a dynamic warm-up consisting of 10 jumping-jacks, 10 air squats and five lunges on each side, and afterwards they did a one-minute walking cooldown.
After six weeks, the participants showed a significant 5 per cent increase in aerobic fitness, compared to a sedentary control group.
A previous study by the same researchers found that those who did the three “snacks” in quick succession with only a short recovery in between (as opposed to the group that took longer breaks) had about double the aerobic fitness, which equated to a 13 per cent lower mortality risk and 15 per cent lower risk of cardiovascular disease.
So although the 20-second snacks are beneficial, lead researcher Martin Gibala of McMaster University in Ontario says it would still be better to do the three sets of sprints in one session.
“That approach requires about 10 minutes in total, which is still a very small time commitment,” Gibala notes, adding that although people say they lack the time to exercise, most are choosing to spend their time elsewhere.
Australian adults spend an average of 13 hours a week watching television, for instance, and about seven hours a day on electronic devices.
“I do think a benefit of studies like our recent effort is to remind people that ‘exercise’ does not have to involve changing into spandex, going to the gym, and requiring an hour time commitment,” says Gibala, stressing that the “snacks” are a good place to start but do not replace the exercise guidelines nor do they provide the same benefits as a more robust routine.
“It’s about working physical activity into your day, and there are countless ways to fit it into our lives in practical ways that do not demand much time, and even this can provide health and fitness benefits.”
Emmanuel Stamatakis is a professor of physical activity, lifestyle and population health at the University of Sydney.
He says that it is a very timely study, particularly given that the recently revised US Physical Activity Guidelines abandoned the 10-minute exercise minimum.
Stamatakis adds that “exercise snacks” are appropriate and achievable for most adults, regardless of their fitness.
“Most people can walk up a few flights of stairs daily, do a few ‘walking sprints’ or park their car a bit further away and carry their groceries for some 50 to 100 metres or so,” he says.
“It is impressive to see how such a low dose of exercise over a short period of time has [such] rapid effects on fitness, one could speculate that if such an activity pattern was maintained long term it would have much more dramatic effects.”
In a paper due to be published in the British Journal of Sports Medicine in February, Stamatakis and his colleagues argue that for those who are overweight or unfit (that is, the majority of Australian adults) “huffing and puffing” regularly through intense incidental activity – which could mean climbing stairs, walking uphill, walking briskly on a level surface or running and playing with children – is a valid way to keep healthy and fit.
Gibala says that there are a host of complex behavioural reasons why people don’t make time to move but finding ways to help them start is important and necesary to reduce the epidemic of chronic disease and obesity, while improving social and emotional health and wellbeing.
“For those who are quite sedentary and just starting out, it is such an emotional gulf to think about getting to the recommended 150 minutes per week of activity,” Gibala says. “The message is, start small and every bit counts.”