The Lycra-clad fitness fans among us like to dine out on their exercise exploits, whether it’s racking up mileage on running tracks or pumping iron in the gym.
But while the rest of us might prefer to chew our own arms off than spend half an hour on the treadmill (and those of us with kids or hectic jobs might struggle to find half an hour at all), new research suggests there’s more value than you might think in smaller portions of activity spread throughout the day.
Studies now show that getting in just a few ‘snack-size’ quantities of activity each day can help you stay healthier and live longer.
One recent paper found that meagre helpings totalling little over three minutes of vigorous activity could cut the risk of all major cardiac events, including heart attack and stroke, by around 45 per cent in UK women. The study focused on people who otherwise considered themselves non-exercisers.
These findings are only now emerging due to modern movement trackers, which allow scientists to monitor people’s activity levels much more accurately than they could by asking them to recall the exercise they’d done.
“Wrist-worn trackers are good for capturing mostly ‘ambulatory’ movement-based activities, like walking, but they’ll also capture vigorous gardening and quite a few other things,” says author of the study, Prof Emmanuel Stamatakis from the University of Sydney.
“One of the reasons we’re able to see such large effects from such small amounts of physical activity is the accurate measurement.”
Stamatakis studies what he calls ‘vigorous intermittent lifestyle physical activity’ (VILPA) – short, intense bouts of activity, such as running upstairs, that people do as part of their daily routines, rather than as ‘exercise’, which implies a level of planning.
An earlier study using tracker data showed that middle-aged and older inactive people who did three 1–2-minute VILPA bouts each day were around 40 per cent less likely to die within seven years compared to those who did none.
The concept of VILPA is similar to that of micro-exercises, or ‘exercise snacks’, which are also known to have health benefits.
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Precision matters
Before fitness trackers, scientists could only get rough estimates of people’s activity from surveys.
“Typically, these ask for bouts of at least 10 minutes of walking, cycling or gardening, so you’ve already cut off many of the [shorter] activities,” says public health expert Prof Lennart Veerman from Griffith University in Brisbane, Australia.
“People can’t really recall what they were doing and if you measure what they are doing imprecisely, then it’s more difficult to establish a relationship with an outcome.”
Veerman’s recent work used data from trackers and looked at the link between activity levels and longevity in Americans aged 40 and over.
The results show that when people are divided into four groups by activity level, every hour of walking done by people in the least active group could add an extra six hours to their lives – and if they increased their overall activity levels to those of the most active group, they could add 11 years.
While Veerman’s study converts all activities into the equivalent of walking, it does take account of differences in intensity. The good news, he says, is that any activity counts. On the other hand, it doesn’t rule out people doing more intense activity for half the time.
The work on VILPA and exercise snacks, meanwhile, looks exclusively at shorter, high-intensity bouts of exercise that Stamatakis says help our hearts to make healthy adaptations.
Something is better than nothing
Currently, the World Health Organization (WHO) recommends at least 150 minutes of moderate-intensity physical activity – or 75 minutes of vigorous-intensity activity – per week.
But recent research across 163 countries suggests that nearly a third of us aren’t achieving this and that activity levels are trending lower. So, could people be more inspired by a less daunting, more flexible target incorporating shorter bursts of activity?
University of Edinburgh-based epidemiologist, Dr Tessa Strain, who led the study, agrees that the current target, which equates to 30 minutes of exercise five times a week “can seem onerous in a busy world”, even though it’s provided for a raft of reasons related to both physical and mental health.
It’s easier to imagine absorbing wider benefits from going for a jog in the park – such as chatting with running buddies or communing with nature – compared to blasting up three flights of stairs.
But for those of us who don’t have the time or inclination, Strain notes that the WHO is also promoting the message: “every move counts”. And the small print in the official guidelines acknowledges that “doing some physical activity is better than none.”
Both VILPA and exercise snacks are potential antidotes to inactivity, the idea being that they can be sprinkled into your daily routine (to get the best results, however, it needs to be done liberally).
VILPA can include any activity you do as part of your day, whereas exercise snacks tend to be more intentional bursts of activity, according to Prof Jonathan Little of the University of British Columbia, one of the originators of the concept: “With exercise snacks, we’ve prescribed or instructed people what to do throughout the day.” An example might be marching on the spot next to your desk or doing jumping jacks before you brush your teeth.
The aim with both concepts is to make physical activity more palatable, particularly for the least active among us. One way to imagine them is like high-intensity interval training (HIIT) workouts, but with much longer recoveries. HIIT crams big fitness boosts into short exercise sessions and Little’s work suggests that exercise snacks could have similar effects.
According to Little, VILPA and exercise snacks are complementary and could help “move the needle” for those who are discouraged by hefty exercise regimes. Stamatakis, meanwhile, is planning future research that combines the two.
One possible issue with VILPA, however, is that it can’t be scheduled. In Stamatakis’s studies, activity is classified in 10-second windows by AI algorithms that learn to identify movements based on tracker data from people doing known movements.
But he admits that the techniques they’re using aren’t perfect and that they’re hoping they’ll soon be able to combine movement data with physiological data – heart rates, for example – to get a more accurate picture of what exercisers are doing.
“This is a work in progress,” he says. “I think we’re about two to three years away and we know it’s going to add accuracy to our predictions.”
Still, based on what we know already, can we ditch the Lycra as long as we’re blazing around the supermarket at top speed? Well, ideally not. None of the experts say short bursts of activity should be seen as a substitute for more traditional exercise regimes, which have proven health benefits.
“This isn’t about competing,” says Stamatakis. “Our main audience is people who, for whatever reason, can’t initiate and stick to an exercise programme.”
On the other hand, even if you’re the sort who devours hour-long workouts for breakfast, you could still treat yourself to the odd snack once in a while.
Read more:
- Exercise can reverse ageing in the brain, study claims
- Group workouts can make you fitter – if you do them right
- Looking to lose weight? Here's why exercise won't work
About our experts
Emmanuel Stamatakis Emmanuel (Manos) is a Professor of Physical Activity and Population Health and Director of the Mackenzie Wearables Research Hub. With over 440 peer-reviewed papers, he has been named a Highly Cited Researcher and Field Leader in Sports Medicine, and co-chaired the WHO’s Physical Activity Guidelines Development Group.
Lennart Veerman is a Professor of Public Health at Griffith University, Australia, leading the Public Health & Economics Modelling group, with expertise in health economics, epidemiological modelling, and the cost-effectiveness of prevention.
Tessa Strain is a post-doctoral fellow at the MRC Epidemiology Unit, specializing in physical activity research, including its measurement, health impacts, and epidemiological methods, with a focus on national surveys and their role in public health policy.
Jonathan Little is a professor from the University of British Columbia, Canada. He is one of originators of the concept of "exercise snacks”.