Overview

• Researchers pooled 11 clinical trials involving 414 physically inactive adults and found significant gains in cardiorespiratory fitness from brief, structured activity bouts.
• Protocols typically prescribed moderate-to-vigorous efforts lasting five minutes or less, performed at least twice daily on 3–7 days per week over 4–12 weeks.
• Adherence was strong, with about 91% overall compliance and roughly 83% retention, indicating the approach is practical for time‑pressed or low‑motivation adults.
• Pooled analyses did not show consistent improvements in body composition, blood pressure or blood lipids, and strength benefits were limited, chiefly to muscular endurance in older adults.
• Common exercises included stair climbing for younger and middle‑aged participants and leg‑focused moves or tai chi for older adults, with authors calling for larger, longer, more consistent trials before policy shifts.