Snacking on Exercise: Could four minutes of exercise really be enough?
|Photo by Bruno Nascimento on Unsplash|
Originally published on Medium on April 9, 2019.
We hate those people.
But I think we all want to feel fit, be healthy, and if we could look great naked, too, well, good. So, the growing interest in the “snack on exercise” movement, with a total of…wait for it…only four minutes of exercise a day sounds pretty fantastic. But is it too good to be true?
Of course it is! Four minutes??? I mean, really.
But then I started to investigate. (As I do.)
I reviewed the research into the snacking on exercise movement here. Go check it out!
Where did this ridiculous idea even come from?
High-intensity interval training, or HIIT, has been around for a while. You’ve probably heard of this training method by now, which combines short bouts of all-out, intense exercise interspersed with active rest, like light cycling.
Now, “all-out intensity” is highly relative to the fitness level and perception of the individual; HIIT, to be properly done, must be at levels between I-feel-terrible and oh-dear-I-just-threw-up. It’s been employed by athletes for at least a century, but we’ve only been seriously studying it for about a decade.
Author’s note: While I do feel that HIIT training sounds better than just HIIT, then I’d be saying “high-intensity interval training training”, which I think we can all agree is stupid.
So, while “HIIT” sounds scary, the fun-and-relatable term “snacking on exercise” was originally coined in a 2014 University of Otago study to describe “snacks” of six, one-minute, all-out workout sessions interspersed with active rest or resistance training in groups of insulin-resistant individuals. They found that, compared to 30-minute sessions of moderate-intensity exercise, those in the snack groups showed more effective blood sugar control. This result — and the catchy title — helped the movement towards less-is-more take off. Most studies — but not all — that have looked into this phenomenon are putting their participants through the paces with HIIT.
HIIT, to be properly done, must be at levels between I-feel-terrible and oh-dear-I-just-threw-up.
“The Snack on Exercise movement is primarily about getting people started,” says Mrs. Parsons, who differentiates between HIIT and her principle of wanting people to make a healthy habit of four, one-minute bouts of exercise over the course of a day. “I really went to reach people who are currently quite sedentary at present (and missing out). It’s about getting them moving regularly because of the incredible benefits the research shows they’ll receive.”
I started my research with the study she cites in her inspiring TED talk.
That 2016 study from McMaster University is mentioned in several news articles on the exercise snacking phenomenon. It is just one of a number of McMaster University studies on the effects of short-bout exercise programmes — as compared to those of longer durations of moderate-intensity exercise — on various health markers and in different populations.
How long do these short bouts have to last?
Some studies show that as little as 36–60 seconds of intense exercise per session (in six-second bursts) are enough to make impressive gains in certain populations. They have shown health improvements in overweight adults with a cumulative one minute of hard exercise, three times per week — that’s three minutes per week. Sedentary students have improved their cardiorespiratory fitness with three, twenty-second snacks of brisk stair climbing per day, for a total of three minutes a week. And they’ve seen insulin sensitivity decrease with “reduced-exertion” high-intensity interval training (a bit of an oxymoron, I think) with only two, twenty-second sprints, three times a week.
Yes, math fans, that’s 120 seconds (or two minutes) of exertion a week. No wonder people are interested.
Does it really have to be high-intensity?
Author’s note: If I come across as totally judging people that hear that they can improve their fitness by working out for just four minutes a day, but then complain that it has to be hard, yeah, that’s about right.
I asked Lauren about intensity. “Numerous studies have shown that by adding a bit of intensity we see much better results in a wide range of health markers including fitness, muscle gain, fat reduction, blood lipid profiles and insulin resistance, than simply doing longer steady state exercise,” she says.
I think I can safely stake my professional reputation on agreeing that higher intensity equals better results, and that the amount of research showing positive results from high-intensity, lower-volume sessions is impressive.
But research into moderate, six-minute exercise sessions and those lasting less than ten minutes per session showed positive results for the participants too: improved blood sugar moderation after meals and cardiometabolic profiles, as well as bold declarations that the results are as good from these ten-minute sessions as if the sessions lasted over 30 minutes. Another study states that participation in both “bouted” and “non-bouted” (shorter and longer than ten minutes, respectively) moderate-to-vigorous activity reduced chances of developing multimorbidity, and recommends that both types of exercise be promoted.
In plain English, then: intense, really short workouts are good for you, but engaging in short, moderate exercise also shows great results if you lead a largely inactive life.
Lauren agrees. “It’s still definitely worth breaking up your day of sitting, as we know that having a sedentary lifestyle — which is defined as six or more hours of sitting per day — increases morbidity and mortality. This remains true even if you exercise at other times — that doesn’t undo the negatives of a sedentary lifestyle. It’s the regular movement breaks that are key.”
Just bear in mind that quality vs. quantity is important with all of your exercise.
Do people enjoy it? Do they stick with it?
So, it’s been clearly established that even a few minutes of exercise a day has physiological benefit. But what about the emotional and motivational benefits of snacking? Does snacking lead to adoption of a regular and/or longer-duration training programme? Do snackers tend to maintain or augment their routines?
Another team at McMaster University found that enjoyment of high-intensity interval exercise actually increases with ongoing training — even those doing it “properly” at I’m-about-to-puke intensity. And a 2012 study reported that a tabata group also reported improved enjoyment of — and intentions to engage in — continued exercise, whereas the endurance group showed no change in enjoyment.
Author’s note: HIIT is sometimes used interchangeably with the term, tabata, a specific form of HIIT with a set ratio of twenty seconds of (very hard) work and ten seconds of rest, eight times, for a total of — you betcha — four minutes of exercise.
A study from the University of British Columbia also suggests that interval training makes exercise more enjoyable for sedentary individuals, and proposes it as a good alternative to traditional continuous exercise for ongoing adherence to exercise. Two other groups studying insulin management in sedentary adults had similar findings: high-intensity, time-efficient training programmes improve participation among inactive populations who otherwise wouldn’t adhere to time-consuming traditional aerobic exercise regimes. As well, they spent more time performing intense physical activity overall per week.
So…yes, and yes.
Two last questions
These are points that I couldn’t find in the existing research, so I’m stating clearly and on the record that more research is needed specific to short-duration exercise, and in fit people in particular.
But! I would assert that, as physiological benefits are consistently shown, and enjoyment and adherence are positive, this is a no-brainer. They should (should, not do) echo the accessory benefits of traditional exercise programmes. The anecdotal evidence, at least, is all positive, as are Lauren’s client testimonials.
My last question to her was simple. So, is four a magical number? Do I have to stop at four minutes?
“No,” declares Lauren. “You certainly don’t have to. This whole concept is about getting you started and ideally getting you moving at four different times throughout your day for a minute or so. If you can increase that and do more, then good on you. Go for it! Just bear in mind that quality vs. quantity is important with all of your exercise. Spending longer periods, particularly doing restorative movement in ways that you enjoy and getting out into nature for good dose of sunlight is also important. It’s all about balance. We just want four minutes to be your baseline every single day.”
Doing a few quick bouts of exercise a day will benefit most people, as long as it is of an intensity higher than they are used to.
Highly-trained individuals can’t expect good results from moderate-intensity exercise “snacks”; they would have to work at near-maximal (barfy) levels.
But the research clearly indicates that untrained or sedentary populations can use very short intervals of exercise to achieve impressive improvements in their blood pressure, blood sugar management, body composition and VO2 Max and have a good chance of enjoying it and sticking with it, whether they be at vomit levels or lower.
My take: it’s an excuse-proof time commitment, with mountains of evidence of physiological benefits, and the studies show that it’s more fun than longer-duration sessions. However, it’s also true that working harder (and putting the HI into HIIT) shows even more benefits, because of course it does.
Author’s note: Although “all out” HIIT models (such as Wingate cycle-type exercise) are the most effective, this type of extremely-high-intensity training may not be safe, tolerable or practical for many individuals.
So, can health and fitness gains really be made by taking on snack-size intervals of exercise, for as little as four minutes’ effort, or less?
It’s too good. And it seems to be true.
So, consult your doctor first, but get up and start snacking!
Interested in getting started? Lauren Parsons offers a free, 7-day Snack on Exercise Challenge and lots of resources for snacking ideas. Give it a try and see how four minutes a day feels for you. (After you consult your doctor.)
Karen (Power) Hough is a writer, editor and blogger with an Honours BSc. in Human Kinetics, whose part-time “superhero job” has been as a fitness instructor for over 20 years. She currently lives in London with her husband, three energetic kids and a codependent dog, and bores/impresses them all with stories about how she used to be a nutritionist, personal trainer and national-level fitness competitor. Her glutes still hurt from a tabata workout three days ago.