Effect of exercise snacks on fitness and cardiometabolic health in physically inactive individuals: systematic review and meta-analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of randomised controlled trials
PubMed 41057224 · doi:10.1136/bjsports-2025-110027
What was done
Authors conducted a systematic review and meta-analysis of randomised controlled trials searched across seven databases through April 2025 (PROSPERO CRD42024616514). They evaluated the effects of exercise snacks (defined as structured bouts lasting 5 minutes or less, performed at least twice daily, at least 3 days per week, for at least 2 weeks) versus non-exercising controls on cardiorespiratory fitness, muscular fitness, and cardiometabolic outcomes in physically inactive adults and older adults aged 65 years and older.
What was found
Across 11 RCTs (n=414; 69.1% women; mean age 18.7 to 74.2 years; intervention duration 4-12 weeks, 3-7 days/week, moderate-to-vigorous to near-maximal intensity): Exercise snacks significantly improved cardiorespiratory fitness in adults (g=1.37, 95% CI 0.58 to 2.17, p<0.005, I2=71.4%, k=6; moderate certainty) and muscular endurance in older adults (g=0.40, 95% CI 0.06 to 0.75, p=0.02, I2=0%, k=4; very low certainty). No significant effects were observed for lower limb muscular strength, body composition, blood pressure, or blood lipid profiles (no numerical values reported for null outcomes). Compliance was 91.1% and adherence was 82.8%.
Why it matters
Brief, distributed exercise snacks provide a feasible option to improve cardiorespiratory fitness with high adherence in inactive individuals. However, short-term exercise snacks do not appear to alter standard resting cardiometabolic health markers.
Limits
The overall evidence base is small (11 RCTs, 414 total participants), with specific outcome meta-analyses including only 4 to 6 studies. Cardiorespiratory fitness analyses had substantial heterogeneity (I2=71.4%), and muscular endurance evidence had very low certainty. Interventions were short (4 to 12 weeks), and the abstract does not report long-term clinical health outcomes.
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- contradicts Performing exercise snacks 4 to 5 times per day several times per week improves VO2 max, blood pressure, fasting glucose, and HbA1c in untrained individuals.