Exercise snacking and physical performance in older adults: a systematic review, meta-analysis, and qualitative evidence synthesis

Exercise snacking distributes brief, structured bouts of exercise across the day and may offer a low-burden option for older adults. This review evaluated its effects on physical performance and synthesised qualitative and implementation evidence on acceptability and feasibility. Seven databases were searched from inception to 18 November 2025 and an update search covered 19 November 2025 to 30 September 2026. Randomised evidence was pooled using random-effects meta-analysis under a strict primary exercise-snacking estimand; single-arm quantitative studies were synthesised descriptively. Qualitative and implementation evidence was synthesised using a framework-informed thematic approach, with direct exercise-snacking evidence separated from indirect Snacktivity/VILPA context. Randomised outcomes were assessed with RoB 2 and certainty of evidence with GRADE. The review was registered in PROSPERO (CRD420261295910). Thirteen unique reports were included. Five randomised controlled trials contributed comparative effectiveness evidence, two single-arm studies were synthesised descriptively, and nine reports contributed qualitative or implementation evidence, with overlap across evidence streams. Exercise snacking favoured five-times sit-to-stand performance (4 trials, 165 participants; mean difference [MD] -1.81 s, 95% CI -2.79 to -0.83; I²=33.8%) and 60-second sit-to-stand performance (4 trials, 147 participants; MD + 4.33 repetitions, 95% CI 2.01 to 6.64; I²=0%); certainty was low for both outcomes. Effects on left-leg balance (2 trials, 94 participants; MD + 5.44 s, 95% CI -6.85 to 17.74) and right-leg balance (2 trials, 94 participants; MD + 4.38 s, 95% CI -4.46 to 13.22) were very uncertain. Direct qualitative evidence indicated that brief duration, home compatibility and flexibility supported acceptability, whereas physical or cognitive burden, repetition, memory problems and technology usability could hinder engagement; tailoring, progression and clear guidance were recurrent facilitators. Low-certainty evidence suggests that exercise snacking may improve short-term sit-to-stand performance in older adults, but the clinical importance of these differences is not established. Effects on single-leg balance remain very uncertain. Direct qualitative evidence suggests that exercise snacking can be acceptable and feasible for some older adults when programmes are appropriately tailored, progressed and supported. Larger, prospectively specified trials are needed before firm clinical or public-health recommendations can be made.