Exercise Snacks Under 60 Seconds Prove Feasible for Inactive Middle-Aged Adults

Physical inactivity remains a global health challenge, with time constraints and lack of gym access cited as top barriers. 'Exercise snacks'—isolated bouts of vigorous activity lasting 60 seconds or less, scattered throughout the day—have emerged as a potentially practical solution that requires no equipment and can be done anywhere. Prior lab-based studies showed cardiorespiratory fitness (CRF) gains after supervised stair-climbing or cycling sprint snacks, but real-world, remotely delivered bodyweight snack interventions in inactive adults had not been rigorously tested.

This two-site RCT enrolled 77 inactive, middle-aged adults (mean age 54 years; 73% female; mean VO2peak ~24.5 mL/kg/min) across McMaster University (Hamilton, ON) and UBC Okanagan (Kelowna, BC). Participants were randomized to an exercise snacks group (n=38; bodyweight exercises such as squats, lunges, and jumping movements) or a placebo control group (n=39; low-intensity stretching). Both groups were instructed to perform ≥3 bouts per day, ≥3 days per week, for 12 weeks, using an online delivery platform. The primary efficacy outcome was VO2peak assessed before and after the intervention; secondary outcomes included blood biomarkers of cardiometabolic health (glucose, lipids, inflammatory markers), rating of perceived exertion (RPE), and exercise enjoyment.

Seventy-three of 77 participants completed the intervention—a strong retention rate of ~95%. Critically, adherence exceeded the prescribed minimum in both groups, with the exercise snacks group completing an average of 173 ± 74 total bouts and the control group completing 158 ± 92 bouts (no significant between-group difference, p=0.37). A predefined feasibility threshold (>70% of participants completing ≥6 of 9 weekly bouts on ≥9 of 12 weeks) was met. RPE was appropriately higher in the exercise snacks group (3.0 ± 0.7 vs. 2.1 ± 0.6; p<0.001), confirming the exercise stimulus was perceived as more demanding. Exercise enjoyment was high and equivalent between groups (~4.2/7 on the Exercise Enjoyment Scale).

Despite strong adherence, no between-group differences were detected in absolute or relative VO2peak (mean difference: 0.0 L/min [95% CI: −0.1, 0.1] and 0.4 mL/kg/min [−0.6, 1.4], respectively). Similarly, blood biomarkers of cardiometabolic health and inflammation did not differ between groups. The study was powered to detect a clinically meaningful 1 MET improvement in CRF, which did not materialize.

The authors conclude that remotely delivered, technology-enabled exercise snacks are feasible and enjoyable for inactive middle-aged adults in real-world settings. However, the current protocol—while time-efficient—may have been insufficient in volume or intensity to drive measurable physiological adaptation. Future iterations may need to increase bout frequency, intensity, or total weekly load. The active control (stretching) design was a methodological strength, helping isolate the exercise snacks effect, though it may have also masked small within-group improvements.