Research

Hormonal

Short-term physical inactivity causes a significant loss of muscle mass (1-4%) in older adults within 14 days, accompanied by anabolic resistance.

If you are over 65, even a short period of reduced activity (like 14 days of low steps) can cause you to lose 1-4% of your muscle mass. This happens because your muscles become less responsive to protein (anabolic resistance). To protect your muscle, try to stay active even if you can't do intense exercise, and ensure you are eating enough protein.

GoodSupportsHIGH confidence
Significant muscle atrophy is seen with only 14 days of step reduction in both young and older adults; the reported 1–4% losses in muscle mass are both striking and concerning, considering that sarcopenic muscle loss is estimated to occur at ~0.8% per year.
Kelly A. Bowden Davies et al. · Therapeutic Advances in Endocrinology and Metabolism · 2019

Why this rating

Based on controlled step-reduction studies in older adults.

Source

Reduced physical activity in young and older adults: metabolic and musculoskeletal implications

Kelly A. Bowden Davies et al. · Therapeutic Advances in Endocrinology and Metabolism · 2019

DOI 10.1177/2042018819888824

narrative_reviewCited 268×
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DOI resolved against Crossref · corpus check 2026-06-10

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