Leg power falls about 3.5% a year between 65 and 89, against 1–2% for strength, and starts to decline after 40
Do you lose leg power faster than strength?
The finding
Across 65–89, differences between age groups equalled losses of 1–2% a year for strength and about 3.5% a year for leg extensor power. Relative leg power began to decline above 40 in both sexes.
- Authors
- Skelton DA, Greig CA, Davies JM, Young A; Alcazar J, Aagaard P, Haddock B, et al.
- Published
- Age and Ageing 23(5):371–7; Journals of Gerontology A 75(7):1369–78; Experimental Gerontology 152:111448 · 1994; 2020; 2021
- Evidence
- Read in the primary source; numbers checked.
- Source
- doi.org/10.1093/ageing/23.5.371
How it was studied
Skelton: cross-sectional, 50 men and 50 women aged 65–89 with strict health criteria. Alcazar: Copenhagen Sarcopenia Study, 1,305 adults aged 20–93.
The numbers
In Skelton, power relative to body weight influenced chair-rise time. In the Copenhagen cohort, relative sit-to-stand power was roughly flat from 30 to 50, then fell by about 0.09 W·kg⁻¹ a year, more slowly in women over 75.
What it does not show
All cross-sectional: per-year figures describe differences between age groups, not change in the same people.
What Longstanding does with it
The sit-to-stand is timed, so it carries leg power as well as strength. The app’s line uses norms at each age, not these rates.