Five minutes, twice a day!

A trend that started on social media has just been put through the academic wringer. A new systematic review and meta-analysis in the British Journal of Sports Medicine pooled 11 randomised trials of so-called exercise snacks and found that they meaningfully improved cardiorespiratory fitness in physically inactive adults (Rodríguez et al., 2026).

The international team, with researchers in Spain, Denmark and the UK, defined an exercise snack as a structured bout of moderate-to-vigorous activity lasting five minutes or less, performed at least twice a day, three or more days a week, for at least two weeks. Across 414 sedentary participants, two-thirds of whom were women, the snacks delivered moderate-certainty improvements in cardiorespiratory fitness. For younger and middle-aged adults the dominant format was stair climbing. For older adults it was leg-focused strength work and tai chi (Rodríguez et al., 2026).

The mechanism is straightforward. Short bursts of moderate-to-vigorous intensity stress the cardiovascular system enough to drive adaptation, even without the bookends of a full workout. This sits alongside earlier wearables research from more than 25,000 non-exercisers, which found that just 3 to 4 minutes a day of vigorous incidental activity, brisk uphill walking, sprinting for a bus, carrying heavy shopping, was linked to substantial reductions in all-cause, cancer and cardiovascular mortality (Stamatakis et al., 2022).

Why it matters

The most common reason people give for not exercising is not money, equipment or motivation. It is time. Public health guidelines still recommend 150 minutes of moderate or 75 minutes of vigorous activity per week (Bull et al., 2020), and many time-poor professionals look at those numbers and disengage entirely.

Reframing those guidelines into ten 90-second windows scattered through the day changes the maths considerably. It also reframes the psychology: a workout you cannot start is worse than a stair climb you actually do.

This matters at population level too. The Rodríguez meta-analysis specifically looked at sedentary adults, the group hardest to reach and most at risk. Improvements in cardiorespiratory fitness in this population are not cosmetic. They translate into measurable reductions in cardiovascular and metabolic disease risk over time.

Practical takeaway

1. Pick a trigger. Stack a snack onto an existing habit, for example, one flight of stairs after each meeting, 60 seconds of squats while the kettle boils, or a brisk walk to and from a colleague's desk rather than a chat over email.
2. Make it feel hard. The evidence is for moderate-to-vigorous intensity. Brisk enough to break breath and raise heart rate, not just a stroll.
3. Aim for at least two bouts a day, most days of the week. The trial data starts at twice daily.

The future of preventative fitness may not be longer sessions in better trainers. It may be smaller doses, taken more often, and made unremarkable.

References:

1. Rodríguez, M. Á., Quintana-Cepedal, M., Cheval, B., Thøgersen-Ntoumani, C., Crespo, I., & Olmedillas, H. (2026). Effect of exercise snacks on fitness and cardiometabolic health in physically inactive individuals: Systematic review and meta-analysis. British Journal of Sports Medicine, 60(2), 133-141.
2. Stamatakis, E., Ahmadi, M. N., Gill, J. M. R., Thøgersen-Ntoumani, C., Gibala, M. J., Doherty, A., & Hamer, M. (2022). Association of wearable device-measured vigorous intermittent lifestyle physical activity with mortality. Nature Medicine, 28(12), 2521-2529. 
3. Bull, F. C., Al-Ansari, S. S., Biddle, S., Borodulin, K., Buman, M. P., Cardon, G., . . . Willumsen, J. F. (2020). World Health Organization 2020 guidelines on physical activity and sedentary behaviour. British Journal of Sports Medicine, 54(24), 1451-1462.