Key numbers
13,423
Total participants
7.0 years
Median follow-up
12.2 percent
Participants who died
0.39
Adjusted hazard ratio, composite fitness highest versus lowest (95% CI 0.32 to 0.48)
Who was studied and for how long
This was a nationwide cohort of community-dwelling adults aged 65 or older in Taiwan who completed standardized fitness assessments between January 11 2015 and November 25 2016. There were 13,423 participants, with a mean age of 72.9 years (standard deviation 6.1); 8,394 (62.5 percent) were women.
Deaths were found through linkage with the National Health Insurance death registry, with follow-up through December 31 2022. The median follow-up was 7.0 years (interquartile range 6.7 to 7.1), and 1,631 participants (12.2 percent) died.
What was measured
Seven tests covered four areas. Cardiorespiratory fitness: the 2-minute step test. Muscular strength: the 30-second arm curl and the chair stand. Flexibility: the back scratch and the chair sit-and-reach. Balance and agility: the 1-leg stance and the 8-foot up-and-go.
The researchers also built a composite fitness index by adding sex-specific percentile ranks across all seven tests. Hazard ratios were adjusted for sociodemographic factors, other health conditions and self-reported physical activity.
What the study found
Four tests showed clear differences between the top and bottom fifths of performance. The adjusted hazard ratios for all-cause mortality were 0.41 (95 percent CI 0.33 to 0.51) for the 8-foot up-and-go, 0.50 (95 percent CI 0.42 to 0.59) for the 1-leg stance, 0.55 (95 percent CI 0.46 to 0.65) for the 30-second chair stand and 0.58 (95 percent CI 0.49 to 0.68) for the 2-minute step test.
The authors summarized that balance and agility, lower-body strength and cardiorespiratory fitness were associated with lower all-cause mortality in a graded manner. People with the highest composite index had the lowest risk, with an adjusted hazard ratio of 0.39 (95 percent CI 0.32 to 0.48) compared with the lowest.
What this study does not show
It does not show that all seven tests tracked mortality: the clear results were for four of them. As an observational study, it shows association, not that better fitness causes a longer life. And its tests and composite index are a different set from the Systematic assessment, so it does not validate Systematic's tests or give anyone a personal risk.
The evidence
Each cited source is labeled according to how it supports the particular claim on this page. Direct test evidence, underlying-capacity findings and population reference values are distinguished from Systematic-defined protocols and standards. Historical development notes are retained internally rather than presented as public evidence. A study of an underlying capacity is never presented as validation of the Systematic test itself.
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Underlying-capacity evidence New source
Wu et al. (2026). Physical Fitness and All-Cause Mortality in Older Adults. JAMA network open.
What it found. In 13,423 community-dwelling Taiwanese adults aged 65 or older followed for a median of 7.0 years, the top fifth on the up-and-go (adjusted hazard ratio 0.41), one-leg stance (0.50), chair stand (0.55) and 2-minute step (0.58) had lower all-cause mortality than the bottom fifth, and the highest composite index had the lowest risk (0.39).
What it does not show. It does not show that all seven tests tracked mortality, that fitness causes lower mortality, or that its battery validates Systematic's different tests.
The Systematic Healthspan Assessment is a physical baseline. It is not a diagnosis, and it does not estimate a biological age, a disease risk or a lifespan.