Can 30 seconds of exercise actually make a difference? Here’s what experts say
Doctors and researchers have long known that exercise is good for your health. For years, federal health agencies and medical associations told Americans to aim for at least 150 minutes of moderate or 75 minutes of vigorous exercise each week, and that physical activity as short as 10 minutes at a time counts toward that total.
But more recently, research began focusing on shorter bouts of activity, often called “exercise snacks,” which can be a few minutes or less — like a quick round of jumping jacks, wall sits or a jog up the stairs on the way to work.
It’s not clear who coined the term, but the concept of the exercise snack — that small doses of activity “count” toward your weekly total — started gaining more traction in medical studies about a decade ago, according to researchers who study the topic. Interest grew after 2018, when U.S. exercise guidelines removed the previous 10-minute threshold, signaling that exercise can be shorter than 10 minutes and still have benefits.
There was nothing magical about the 10-minute minimum, said Dr. Robert Nied, a sports medicine specialist at Kaiser Permanente in San Francisco. It was more that many studies used 10 minutes as a common protocol, just as they once often used 30 or 60 minutes.
This opened the door to questions like what length of time qualifies as physical activity and how frequent or intense those intervals must be to benefit heart health, blood sugar levels and other key health measures.
Researchers are still trying to figure out some of those answers, but the consensus so far is that exercise snacks have clear benefits.
“We used to think you have to (exercise) at least 10 minutes at a time for it to matter,” said Marily Oppezzo, an instructor of medicine at the Stanford Prevention Research Center who studies exercise snacks. But “your body doesn’t care if you do it all in one place at a time for it to count. That belief is an artifact.”
Exercise snacks can break up long stretches of sitting, which harms your health starting at as little as two consecutive hours by negatively affecting insulin resistance.
“Even 30 seconds of walking can reverse some of the effects of prolonged sitting,” Oppezzo said. “Or do some body-weight squats. Just use your large limbs.”
Snacks can also make exercise feel more accessible to the many people who struggle to meet that 150-minute-a-week goal. And they’re a chance to get in activities you might not normally do in your regular workout, even if you’re already a consistent gym-goer.
Here’s how experts say you can get the most out of your exercise snacks:
Aim for moderate to high intensity
While simply walking is beneficial because it interrupts sedentary time, upping the intensity offers more benefits, experts said. In most studies on exercise snacks, people are moving “pretty vigorously,” Nied said.
“It’s not, ‘I get up and walk to the fridge and back,’” he said. “It’s, ‘I’ve got to get my heart rate up.’”
Nied recommends shooting for a 5 out of 10 on a scale of perceived exertion, or a pace of walking that would take about 20 minutes to cover a mile — the equivalent of 3 mph.
“You should be out of breath enough that you can’t sing an aria but you could still carry on a conversation,” he said. “That’s your target zone for how hard you’re doing these snacks.”
Office workers can achieve this, for instance, by parking farther from the office and walking a longer distance in, or by doing short spurts of bodyweight exercises during the day, like squats or burpees, he said.
Getting your heart rate up frequently is important because “it gives your heart and body a chance to go, ‘Oh, I have to work. Then I have to calm down. And this is OK,’” Oppezzo said. “If you only do that once a month, your body thinks that was a fluke and we don’t have to do it again. But if you’re doing this a couple times a day, your body thinks, ‘Oh, we better make this easier,’ and it adapts. This is what conditioning is.”
Experts say short bursts
of movement — including exercises like squats — can improve health and
make it easier to fit physical activity into a busy day.
Strength training may have more benefits
In one study Oppezzo is working on, participants did either walking snacks or strength snacks (bodyweight exercises like wall sits and single-leg sit-to-stand exercises) for a couple of minutes at a time, a few times a day, for several weeks.
Both groups got stronger, but the strength group got a lot stronger, she said.
Snacks benefit even those who work out regularly
Everyone can benefit from exercise snacks, but how much you benefit probably depends on your baseline activity level.
There’s a principle in exercise research known as Paffenbarger’s rule, which says that the greatest benefit will be for those who start out sedentary and then do a little activity. Those who are already active and add to that will still benefit, but less dramatically than those who start at zero.
“A little goes a long way initially,” Nied said.
But those who already work out consistently can still benefit from snacks.
“Maybe on days you aren’t going to the gym, you’re doing these little things,” Nied said. “Or you spend less time at the gym because you’re doing these little things.”
Oppezzo recommends doing something you wouldn’t normally do during your regular workouts, like meditation while walking.
Planning ahead may help motivate you
Oppezzo’s research suggests that people are more likely to do exercise snacks if they’ve decided what they’re going to do beforehand — say, strength on Monday, stretch on Tuesday, high-intensity on Wednesday.
“Do whatever you’re going to do, but it helps to decide ahead of time,” she said. “Otherwise you might get to your time and waffle about what to do, which makes you less likely to do anything.”
Anecdotally, she’s observed in her research that people are more likely to have snacks later in the day if they have one in the morning. This is because some people fall into an all-or-nothing way of thinking.
“If they don’t have one done by lunch, they’re like, ‘Ugh, this whole day is a fail. I’ll start tomorrow,’” she said.
‘Dose’ may not matter that much
Don’t get too hung up on how many minutes or how often you should snack, experts said. The most important thing is to do something, and try to make it something that’s sustainable.
“I’m not as concerned about what’s the right dose,” Oppezzo said. “I care about what people will do and for the long-term. It can be 30 seconds, that’s it. Maybe it’s 30 seconds of a wall sit. And get back to work. And give yourself the win.
“It’s just a snack. Don’t overthink it. Just do a thing,” Oppezzo said.