Narrative review on exercise snacks for interrupting sedentary time and improving health markers

Sedentary behavior is associated with higher all-cause mortality and increased cardiometabolic risk, while lack of time remains a major barrier to regular physical activity (PA). Exercise snacks are a daily-life PA strategy characterized by short, repeatable bouts of activity distributed across multiple time points throughout the day. This format may help interrupt prolonged sitting and increase overall PA exposure with minimal reliance on dedicated facilities or equipment. This narrative review, informed by a structured literature search, aimed to (i) clarify the conceptual boundaries between exercise snacks and related approaches, (ii) summarize key prescription elements—frequency, intensity, time, type, and timing (FITT+T)—and their physiological and behavioral rationale, and (iii) synthesize evidence on applications across populations and settings, associated health effects, and implementation considerations. Relevant literature was searched in PubMed (MEDLINE) and Scopus from database inception to September 30, 2025, supplemented by reference-list screening and iterative manual searches. Evidence was synthesized thematically. For health-related outcomes, systematic reviews and meta-analyses were prioritized where available, with individual randomized controlled trials and other primary studies cited selectively when needed for specific populations, outcomes, protocols, or newer evidence. Overall, current evidence suggests that exercise snacks can improve sedentary patterns and may increase activity levels in some contexts. Favorable effects have been reported for postprandial glucose and insulin responses, and some protocols sustained over several weeks have also been associated with improvements in cardiorespiratory fitness and physical function. However, evidence remains limited or inconsistent for blood lipids, body composition, psychological outcomes, and several longer-term clinical endpoints. Most studies report high acceptability and adherence, but real-world implementation may be hindered by forgetting, contextual constraints, and variability in individual capacity. Future research should establish greater consistency in terminology and FITT+T reporting, clarify dose-response relationships across outcomes and populations, leverage wearable and mobile health technologies to support detection and prompting of brief activity bouts, and conduct stratified trials with longer follow-up in high-risk and special populations to support scalable translation into public health and clinical practice.