Exercise Snacks: Why Short Bursts of Hard Effort Count

Most exercise advice assumes you have a block of time to give it: a run, say, or forty minutes at the gym after work. In a lot of weeks that block doesn’t exist, and the advice turns into one more thing you mean to start. US activity guidelines used to count only bouts of ten minutes or more, which didn’t help. The 2018 edition dropped that rule.

A newer line of research looks at the minute or two of hard effort people already do without calling it exercise, like taking the stairs fast because you’re late, or carrying the shopping up a steep street in one trip. Researchers have started calling these bursts exercise snacks. For people who don’t exercise at all, the early findings are encouraging.

What Wrist Trackers Picked Up

The best-known study comes from the UK Biobank. Emmanuel Stamatakis and colleagues at the University of Sydney looked at 25,241 adults, average age about 62, who said they did no exercise in their spare time and who had worn an activity tracker on the wrist for a week. Software picked out short spells of vigorous movement in their ordinary days, and the team then followed everyone for about seven years.

People who had about three such spells a day, each lasting one to two minutes, had a 38–40% lower risk of dying from any cause, and from cancer, than people who had none. Their risk of dying from cardiovascular disease was 48–49% lower.

Stamatakis, E. et al. (2022). “Association of wearable device-measured vigorous intermittent lifestyle physical activity with mortality.” Nature Medicine, 28(12), 2521-2529.

This is observational data, with an obvious weak spot. People who are already unwell are less likely to hurry up stairs, so part of the gap could be illness showing up early rather than the bursts protecting anyone. The researchers ran checks to reduce that bias, but a study like this can’t rule it out. It’s also worth remembering who was studied. These were people doing no exercise at all, so the comparison is between a few short bursts and nothing.

Testing It on Stairs

Small trials have tested the idea more directly. In one, published in 2019, sedentary young adults climbed three flights of stairs (60 steps) at a brisk pace, three times a day, three days a week. After six weeks their peak oxygen uptake, a standard measure of cardiorespiratory fitness, had risen by about 5% compared with a control group who skipped the climbs.

Five percent is a modest change, and it came from a few short climbs a day. That matters because cardiorespiratory fitness is closely tied to long-term health, which we covered in our article on VO2 max. Still, this was a small six-week trial in young people, and it tells us nothing about lifespan.

Jenkins, E.M., Nairn, L.N., Skelly, L.E., Little, J.P. & Gibala, M.J. (2019). “Do stair climbing exercise ‘snacks’ improve cardiorespiratory fitness?” Applied Physiology, Nutrition, and Metabolism, 44(6), 681-684.

In a 2022 review, Hashim Islam, Martin Gibala and Jonathan Little (the last two worked on the stair trial) define an exercise snack as an isolated bout of vigorous exercise lasting a minute or less, repeated a few times across the day. That’s a little stricter than the UK Biobank definition, but it describes the same habit. They see it as a promising approach for heart and metabolic health and are careful to call the evidence early.

Islam, H., Gibala, M.J. & Little, J.P. (2022). “Exercise Snacks: A Novel Strategy to Improve Cardiometabolic Health.” Exercise and Sport Sciences Reviews, 50(1), 31-37.

Fitting Three Into an Ordinary Day

Three a day is a sensible place to start. It’s what the stair trial used, and it’s the level the Biobank figures above refer to. The effort has to be hard, though. A simple check is your breathing: by the end of the burst you should be puffing enough that a full sentence would take some work. A slow plod up one flight won’t get you there, while two or three flights at a steady push usually will.

The easiest bursts to keep up are the ones tied to something you already do. Take the stairs fast on the way to your desk and again after lunch. Walk the last uphill stretch home as if you’re about to miss a bus. If you work from home, a minute on the stairs between calls works too. Squats or push-ups done briskly enough to leave you breathing hard follow the same principle, though they’ve been studied less.

If you haven’t been active for a long time, start with one burst a day at a pace that leaves you puffing rather than wrecked, and add more over a couple of weeks. If you have a heart condition, or you get chest pain, dizziness or unusual breathlessness when you exert yourself, talk to your doctor before you push the pace.

The trouble with two-minute efforts is that nobody remembers them by Friday. In Lamplit you can log them as a workout: choose stair climbing as the type, enter two minutes and set the intensity to intense. If three tiny entries feel silly, add up the day’s bursts into one entry in the evening. And if you later want more structure, the free Foundations plan in the same tracker runs for four weeks, with bodyweight sessions of roughly 7–20 minutes and a guided runner that counts your reps and rests.

Log your first two-minute workout in Lamplit. It’s free and takes a few seconds.