Standing on one leg for up to 30 seconds sounds like a party trick. In a study of more than 13,000 older adults, better performance on that simple balance test was associated with a lower risk of dying over the following seven years.
Researchers followed 13,423 community-dwelling adults aged 65 and older in Taiwan for a median of seven years, measuring their physical fitness through a battery of practical tests. Older adults who performed best on balance, agility, and lower-body strength tests were far less likely to die during the follow-up period than those who performed worst. Even after accounting for existing health conditions, income, body weight, and self-reported exercise habits, the connection held.
Doctors typically size up an older patient’s risk by counting diagnoses: high blood pressure, diabetes, kidney disease. Fitness testing, the researchers argue, measures something a diagnosis list misses, which is how much functional capacity a person’s body still has in reserve. Published in JAMA Network Open, the study is among the largest to test that idea across several fitness domains at once.
What the Physical Fitness Tests Actually Measured
This was a cohort study, meaning researchers measured something about a group of people at one point in time, then followed them to see what happened. Between January 11, 2015, and November 25, 2016, participants completed standardized fitness assessments at 46 testing stations spread across 22 cities and counties in Taiwan. Those results were linked to national health insurance records, which tracked deaths through December 31, 2022.
Of the 13,423 participants in the final analysis, the average age was about 73. Roughly 62.5% were women. Over the follow-up period, 1,631 participants, about 12% of the group, died.
Seven tests covered four areas of fitness. Balance and agility were measured two ways: standing on one leg with eyes open for up to 30 seconds, and an “8-foot up-and-go” test that required rising from a chair, walking 8 feet around a cone, returning, and sitting back down, all timed as one continuous movement. Muscle strength was measured two ways as well: how many times someone could stand up from a chair and sit back down in 30 seconds without using their arms, and how many times they could curl a hand weight in 30 seconds. Heart and lung endurance came from a 2-minute step test, counting how many times a participant could lift each knee to a marked height while marching in place. Flexibility was checked with two reaching tests, one behind the back and one toward the toes while seated.
Participants were then ranked into five equal groups, from lowest to highest performance, for each test. Landing in the top group consistently meant a far lower risk of dying than landing in the bottom one.
Balance and Agility Showed the Steepest Survival Gap
Across several tests, top performers had roughly half, and in some cases less than half, the mortality risk of bottom performers, even after adjusting for age, sex, body weight, income, education, existing conditions, and self-reported physical activity.
On the 8-foot up-and-go, the best performers had a mortality risk about 59% lower than the worst. On the one-leg stance, the gap was about 50%. Lower-body strength and heart-and-lung endurance each landed in the range of 42% to 45%.
Flexibility behaved differently. Extreme stiffness was linked to higher mortality risk, but gains beyond a moderate, functional range of motion produced no further survival benefit. Extreme stiffness appeared to matter far more than exceptional flexibility did.
Combining all seven scores into a single fitness index sharpened the picture. Participants in the top fifth of overall fitness had about 61% lower mortality risk than those in the bottom fifth, a stronger association than any individual test produced on its own. And the pattern was graded: at every step up the index, from worst to best, mortality risk fell.
Most of that difference was concentrated between the very lowest group and the ones just above it. Researchers took that pattern to mean the biggest health gains may come when someone moves out of the worst-performing tier, and argued for prioritizing the least-fit older adults.
Why Balance and Lower-Body Strength Carry So Much Weight
Balance and lower-body strength likely stand out because of their role in preventing falls. Impaired balance, slowed mobility, and weak legs are established risk factors for falls and the fractures that follow, especially broken hips, which rank among the leading causes of hospitalization, disability, and death in older adults. A one-leg stance or a timed up-and-go may catch early declines in muscle control and coordination well before a person ever trips. That remains an interpretation rather than a proven chain of events, since the study tracked deaths from any cause and never measured whether fewer falls or fractures accounted for the gap.
Men and women showed somewhat different patterns. Among men, balance and agility carried the lowest mortality risk, followed by heart and lung fitness. Among women, lower-body strength mattered about as much as balance and agility. Researchers pointed to the higher rates of osteoporosis in older women, along with reports of higher sarcopenia prevalence under certain definitions, as reasons that preserving leg strength and mobility may matter especially for them.
One detail stands out for anyone who assumes a self-report is good enough: the fitness results stayed tied to mortality even after researchers statistically accounted for whether participants said they got regular exercise. Only about a third of the group, 32.8%, reported being regularly active. Measured performance added information that a questionnaire about habits did not capture on its own.
Source : https://studyfinds.com/balance-agility-test-predict-dying-risk-7-years/
