The five chair stand test, abbreviated CST-5, is a 60-second assessment of leg strength, endurance, and balance. Participants begin seated in a chair with their arms folded across their chest, then rise to a full standing position and sit back down five times as quickly as they safely can. The clock captures everything that matters about lower-body function: the explosive power of the quadriceps and gluteal muscles, the cardiovascular capacity to sustain repeated effort, the proprioceptive control needed to keep the body stable through each transition, and the joint mobility that allows a full range of motion at the hips, knees, and ankles. Because standing up from a chair is an activity most people perform dozens of times a day without thinking, failure to do it five times in a row represents a meaningful departure from normal physiological function rather than an abstract laboratory measurement.

Geriatricians have used the CST-5 for years to evaluate elderly patients, and a robust body of work has linked poor performance to elevated risks of falls, frailty, disability, and death in people over 65. What has been missing is evidence about the test’s relevance for middle-aged adults, a group that generally falls outside the scope of physical performance screening. The new study, led by Nicolle A. Mode, Alan B. Zonderman, and Michele K. Evans, set out to fill that gap by following a socioeconomically diverse cohort of 2,943 adults aged 30 to 64 enrolled in Baltimore, Maryland. The researchers measured chair stand performance at four separate study visits and tracked mortality over an 18-year follow-up period spanning 2004 to 2022.

The study’s longitudinal design is what gives its conclusions real weight. Rather than taking a single snapshot of physical ability, the investigators recorded CST-5 results at repeated visits, with participants averaging 2.5 assessments each. At enrollment, the participants had a mean age of 48.7 years, and by the fourth visit their mean age had risen to 59.7 years. Using Cox regression models with time-varying covariates, a statistical approach that allows the analysis to incorporate updated test results as participants aged, the team could ask whether changes in chair stand ability over time tracked with changes in mortality risk. This design helps distinguish between people who were always physically limited and those whose function declined during the study window, offering a more nuanced picture than a single baseline measurement ever could.

The headline finding is stark. People who were unable to complete the five chair stands had a hazard ratio of 2.19 for mortality, with a 95 percent confidence interval of 1.65 to 2.92, compared with participants who finished the test in less than 13.7 seconds. In practical terms, failing the test more than doubled the risk of dying during the follow-up period, and the confidence interval sits comfortably above 1.0, indicating the result is statistically robust. Just as striking is how common test failure was in this relatively young cohort: the proportion of participants unable to complete the CST-5 rose from 19 percent at the first visit to 31 percent at the fourth visit. Nearly one in five adults in their thirties through fifties, an age range when most people assume their bodies are still resilient, could not perform a movement that healthy adults typically manage without effort.

Perhaps the most clinically provocative detail concerns the disconnect between test failure and self-reported function. Among participants who could not complete the CST-5 at the first visit, half reported no difficulties getting out of a chair in their daily lives. This gap between subjective experience and objective performance suggests that many middle-aged adults are unaware of the physiological decline their bodies are quietly undergoing. Daily chair transfers are typically performed at a self-selected, comfortable pace with plenty of recovery time between efforts, which can mask deficits in the strength and endurance that a timed, repeated test exposes. A patient who feels fine standing up from the sofa after dinner may nonetheless lack the lower-body power reserve that predicts long-term survival, and without a standardized test, neither the patient nor the physician would ever know.

Intriguingly, the data suggest that the critical threshold is not speed but the binary ability to finish at all. Among participants who did complete the test, there was no statistically significant difference in mortality risk between slower and faster performers; the hazard ratio comparing the two groups was 1.24, with a 95 percent confidence interval of 0.95 to 1.62, a range that includes the null value of 1.0. In other words, once a person can complete five stands, finishing in 15 seconds rather than 10 does not appear to carry a measurable survival penalty in this cohort. The message for clinicians is therefore refreshingly simple: the first question to ask is not how fast a patient can stand, but whether the patient can stand five times at all. Inability to complete the test is the red flag that demands attention.

The researchers also tested whether the association held up when other known mortality risk factors were taken into account. Adding additional covariates to the statistical models did not change the main findings, indicating that the CST-5 captures physiological information that standard risk factors miss. This independence matters because it implies the test is not merely a proxy for age, body weight, or self-reported health status. Instead, it appears to integrate the function of multiple body systems, including muscle mass and quality, neuromuscular coordination, cardiovascular reserve, and joint integrity, into a single number that reflects overall biological resilience. No questionnaire or blood panel currently provides that kind of integrated functional snapshot so cheaply and quickly.

The practical appeal of the CST-5 lies in its extraordinary simplicity. The test requires nothing more than a sturdy chair, a stopwatch, and about a minute of a clinician’s or patient’s time. There are no laboratory fees, no calibration, no specialized training beyond basic instruction, and no exposure to radiation or contrast agents. In an era when health screening increasingly depends on expensive imaging and biomarker panels, a test that costs essentially nothing yet doubles as a mortality predictor for middle-aged adults is a rare and valuable commodity. The authors argue that the CST-5 may provide important clinical information for middle-aged adults in an easy-to-administer format, and the new evidence gives that argument considerable force.

For the public, the takeaway is both sobering and actionable. Middle age is when the physiological foundations of late-life health are quietly laid, and the ability to rise from a chair five times in succession turns out to be a surprisingly sensitive barometer of those foundations. Failing the test does not seal anyone’s fate, but it should prompt a conversation with a healthcare provider about strength training, physical activity, and the underlying conditions that may be eroding muscle and balance. Half of the people who failed the test in this study felt perfectly capable of getting out of a chair, which means self-assessment is not enough. A one-minute test administered at a routine checkup could reveal a risk that neither patient nor doctor suspected, and the earlier that risk is identified, the more years remain to do something about it.

Subject of Research: The five chair stand test as a predictor of mortality risk in middle-aged adults

Article Title: Middle-aged chair stands predict mortality risk

Article References: Mode, N. A., Zonderman, A. B., & Evans, M. K. (2026). Middle-aged chair stands predict mortality risk. PLOS Aging and Health, 1(2), e0000026. https://doi.org/10.1371/journal.page.0000026

Image Credits: AI Generated

DOI: 10.1371/journal.page.0000026

Keywords: chair stand test, mortality risk, middle-aged adults, physical performance, leg strength, longitudinal study, Cox regression, aging, functional assessment, screening, PLOS Aging and Health, balance

The analysis drew on data from 120 generally healthy, middle-aged adults enrolled in the Alpha-ketoglutarate supplementation and BiologicaL agE in middle-aged adults trial, known as ABLE. The study was a double-blind, randomized, placebo-controlled trial registered as NCT05706389, designed to test whether six months of daily oral supplementation with one gram of alpha-ketoglutarate, a naturally occurring metabolite implicated in cellular metabolism and previously studied in aging research, would influence biological age measures in people in midlife. Participants, who had a mean age of 50.6 years with a standard deviation of 6.0 years and were evenly split between women and men, were assigned to either the supplement arm, with 59 participants, or the placebo arm, with 61 participants, and followed for six months with an additional three-month follow-up period.

At each of four study visits, participants were instructed to wear an ActiGraph wGT3X-BT accelerometer for seven consecutive days. These devices are small, lightweight triaxial accelerometers widely used in physical activity research, capable of recording movement patterns around the clock and generating objective estimates of activity intensity, sleep timing, and circadian rhythm. In the context of a gerotherapeutic trial, such continuous data streams serve as digital phenotypes: objective, high-resolution markers of physical behavior that may change as a person’s biological aging trajectory shifts. The research team, led by Jessica K. Lu and colleagues including Brian K. Kennedy and Andrea B. Maier, set out to determine whether this level of monitoring was genuinely workable for a population of adults in their late forties and fifties, a group often overlooked in aging trials that tend to focus on either younger volunteers or frail older adults.

The adherence results were striking. The median accelerometer wear time was 24 hours per day, meaning that the typical participant kept the device on essentially continuously throughout each seven-day monitoring window, removing it only briefly if at all. More than 80 percent of participants achieved at least four valid days of wear per visit, a threshold commonly used in the field to define an adequate monitoring window for physical activity analysis. Supplement use adherence exceeded 90 percent across the six-month intervention, indicating that participants managed both the passive monitoring and the active intervention components of the trial simultaneously without meaningful compromise on either front. Device-related operational concerns, such as malfunctioning units, charging difficulties, or discomfort, were minimal across all four visits, suggesting that the ActiGraph platform and the study’s implementation protocols were well matched to the needs and habits of middle-aged participants.

Equally important was what the researchers learned about who stayed in the study. Overall dropout across the trial was 17 percent, a figure that compares favorably with many longitudinal intervention studies but still represents a meaningful loss of statistical power and resources. To understand what predicted attrition, the team turned to survival analysis, specifically Cox proportional hazards models with study visit as the time scale. This approach allowed the investigators to account for when during the trial each participant dropped out, rather than simply tallying who finished and who did not, thereby using the full longitudinal structure of the data. The models tested whether the amount of time participants wore the accelerometer, or their overall adherence to the device, was associated with their risk of leaving the study before completion.

The results of those models carried a provocative implication: every additional minute of accelerometer wear time was associated with a lower hazard of dropout, with a hazard ratio of 0.998 and a 95 percent confidence interval of 0.997 to 0.999. While a hazard ratio per minute may sound small, the effect compounds across the thousands of minutes in a seven-day wear window, and the confidence interval excludes the null value of 1.0, indicating a statistically reliable association. In practical terms, participants who kept their devices on longer were meaningfully less likely to abandon the trial. The authors suggest that wear time may function as a behavioral marker of engagement, a real-time signal that trial coordinators could monitor to identify participants at elevated risk of dropping out and intervene before they disengage entirely.

Sex emerged as the other significant predictor. Being male was associated with a substantially lower risk of dropout, with a hazard ratio of 0.208 and a 95 percent confidence interval of 0.065 to 0.663. In other words, men in this cohort were roughly one-fifth as likely to leave the study as women, a large and statistically robust difference. The finding raises questions about whether middle-aged women face different burdens or motivations in aging intervention trials, whether the supplement or monitoring protocol interacted differently with women’s daily routines, or whether other unmeasured factors drove the disparity. The authors note that understanding and addressing this gap will be important for designing future trials that retain diverse participants and produce generalizable results.

Beyond the statistical associations, the study offers a practical playbook for trial designers considering wearable-based digital phenotyping. The near-universal 24-hour wear pattern suggests that middle-aged adults are willing to treat research accelerometers much like consumer fitness trackers, integrating them into daily life with little prompting. The high rate of achieving at least four valid days per visit indicates that a seven-day monitoring window provides a comfortable buffer, allowing participants to accumulate sufficient data even with occasional removals for bathing or charging. The minimal rate of device-related operational concerns implies that established research-grade hardware, paired with clear instructions and structured visit schedules, can avoid the technical pitfalls that sometimes plague wearable deployments, such as data loss, initialization errors, or participant confusion about when to wear the device.

The implications extend to the growing field of gerotherapeutics, where interventions aim not to treat a single disease but to slow, halt, or reverse the biological processes of aging themselves. Trials in this space increasingly rely on multidimensional readouts, from epigenetic clocks and blood biomarkers to continuous sensor data, to capture the subtle, systemic changes that aging interventions are designed to produce. Accelerometer-derived phenotypes, including total activity volume, activity fragmentation, and sleep-wake rhythms, are attractive because they are objective, repeatable, and sensitive to functional change. The ABLE analysis demonstrates that such data can be collected at high fidelity in a placebo-controlled supplement trial without overburdening participants or inflating dropout, removing a key practical objection to including wearables in future gerotherapeutic study designs.

The authors are careful to frame the work as exploratory, drawn from a single trial with a relatively homogeneous cohort of generally healthy middle-aged adults, so the findings may not generalize to older, frailer, or more clinically diverse populations, where device tolerance and dropout dynamics could differ substantially. Still, the central lessons are actionable: monitor wear time as an early-warning indicator of disengagement, attend to sex differences in retention, and design monitoring protocols around the demonstrated willingness of middle-aged adults to wear accelerometers continuously. As interest in alpha-ketoglutarate and other candidate gerotherapies accelerates, the operational insights from ABLE arrive at an opportune moment, offering trialists a data-driven foundation for building studies that keep participants engaged, keep sensors on wrists, and keep the digital phenotype data flowing from the first visit to the last.

Subject of Research: Feasibility and adherence of accelerometer-based digital phenotyping in a gerotherapeutic supplementation trial in middle-aged adults

Article Title: Optimizing accelerometer implementation in a gerotherapeutic trial: Feasibility, adherence, and operational insights of ABLE

Article References: Lu, J. K., Wang, W., Chew, Y. E., Guan, L., Kennedy, B. K., & Maier, A. B. (2026). Optimizing accelerometer implementation in a gerotherapeutic trial: Feasibility, adherence, and operational insights of ABLE. PLOS Digital Health, 5(9), e0001691. https://doi.org/10.1371/journal.pdig.0001691

Image Credits: AI Generated

DOI: 10.1371/journal.pdig.0001691

Keywords: accelerometers, digital phenotyping, gerotherapeutics, alpha-ketoglutarate, clinical trial adherence, study dropout, middle-aged adults, wearable technology, ActiGraph, Cox proportional hazards, aging intervention, PLOS Digital Health

The study, led by Peck Tiang Joanna Yeo, Rayner Kay Jin Tan, and Miho Asano of the National University of Singapore, with Asano also affiliated with the University of British Columbia, is notable for a simple but consequential framing decision. Whereas the vast majority of successful-aging research canvasses people who are already old, Yeo and her colleagues turned the lens on the cohort that will become Singapore’s next generation of elderly citizens. The rationale is straightforward: expectations, anxieties, and support needs formed in midlife may differ substantially from those of today’s 75-year-olds, shaped as they are by different economic conditions, family structures, and cultural attitudes toward health and money. If aging policy is built only around the experiences of current elders, it risks addressing yesterday’s needs rather than tomorrow’s.

To capture those forward-looking perspectives, the team conducted semi-structured qualitative interviews with 30 middle-aged Singaporeans, probing how participants understood successful aging, what they believed they would need to achieve it, and whether existing state initiatives aligned with those needs. Interview data were subjected to thematic analysis, a rigorous qualitative technique in which researchers systematically code transcripts to identify recurring patterns of meaning across respondents. This method does not quantify how common a view is; instead, it maps the conceptual terrain, revealing the dimensions along which ordinary people organize complex life goals. From the transcripts, four dominant themes crystallized: physical, financial, social, and psychological health, each subdivided into finer subthemes that together paint a granular portrait of what a good old age means to Singapore’s midlife generation.

The physical health theme, perhaps unsurprisingly, centered on staying functional. But the study’s most provocative finding lies in how participants related to disease and disability. Rather than imagining successful aging as the complete avoidance of age-related illness—an ideal long associated with the influential Rowe and Kahn model, which defined successful aging as low probability of disease, high cognitive and physical function, and active engagement with life—many middle-aged respondents felt that accepting age-related diseases and functional disabilities as an expected part of later life was itself a marker of aging successfully. In other words, success was reframed not as the absence of decline but as the capacity to anticipate, absorb, and adapt to it. This echoes a broader shift in gerontology away from rigid biomedical definitions, which studies have repeatedly shown describe only a small fraction of older adults, toward multidimensional and self-rated conceptions in which people managing chronic conditions can still consider themselves aging well.

The financial theme proved equally emphatic, and arguably the study’s most actionable finding. Participants consistently identified early financial preparation as a prerequisite for the old age they envisioned. Middle-aged Singaporeans described the need to save, plan, and acquire financial literacy decades before retirement, viewing later-life security as something constructed incrementally through the working years rather than patched together at their end. This aligns with a substantial empirical literature linking financial literacy to retirement planning outcomes across countries, from the United States to Finland, and to financial resilience in middle and older adulthood. It also reflects a distinctly Singaporean context: the city-state’s retirement income architecture, built around the Central Provident Fund and personal responsibility, places considerable weight on individual foresight, making the timing of financial preparation a genuine determinant of later-life welfare.

Social and psychological dimensions rounded out the picture. On the social front, participants emphasized maintaining relationships, staying connected to family and community, and guarding against the loneliness that decades of prospective research have linked to declining health in old age. Psychologically, respondents spoke of cultivating resilience, realistic expectations, and a sense of purpose—capacities that gerontological research suggests buffer well-being against the inevitable losses that accompany aging. Notably, studies on expectations have found that neither blind optimism nor corrosive pessimism serves people well when health deteriorates; instead, a calibrated realism about what lies ahead appears protective. The middle-aged Singaporeans in this study seemed to intuit precisely that, describing a stance toward the future that was neither denial nor dread but pragmatic preparation.

The second half of the study is what elevates it from descriptive to prescriptive. The researchers systematically compared their identified themes and subthemes against the Singapore 2023 Action Plan for Successful Ageing, the government’s national framework of initiatives spanning health promotion, lifelong learning, senior employment, and age-friendly environments. This audit revealed two distinct categories of misalignment, which the authors label temporal and contextual mismatches. Temporal mismatches are cases where the Action Plan already offers the right kind of support, but at the wrong life stage—initiatives aimed at current seniors that would serve middle-aged adults equally well if accessed later, requiring no redesign of the initiatives themselves. Contextual mismatches are more demanding: needs expressed by future older adults that current initiatives simply do not address in their present form, and which would require genuine tailoring or entirely new provision.

The distinction matters practically. If the gap between what future elders need and what the state provides is purely temporal, policymakers can simply extend the runway—communicating earlier, enrolling earlier, and encouraging midlife engagement with programs already on the books. But contextual mismatches signal genuine blind spots. The study’s findings suggest, for example, that supporting people to psychologically reframe disease and disability as a normal part of aging, and to begin serious financial preparation in their thirties and forties, may not be adequately covered by initiatives calibrated to the current elderly population. Closing those gaps, the authors argue, is essential if the Action Plan is to serve the people who will actually depend on it in the coming decades.

The demographic stakes could hardly be higher. Singapore’s population is aging at a pace few nations have experienced, compressing into a single generation a transition that took European societies a century. Ongoing research has documented the country’s rapid shift, with rising life expectancy, falling fertility, and a shrinking ratio of working-age adults to seniors. Globally, life expectancy has climbed continuously for over 150 years, and extending healthspan—years lived in good function, not merely years lived—has become a central goal of public health. For Singapore, a young nation confronting an old-age profile, the question is not whether its population will age but whether its institutions will anticipate the needs of those aging.

By filling a genuine gap in the literature—the perspectives of future rather than current older adults—the study offers service providers and policymakers evidence-based targets for intervention. Its recommendations are unsentimental: help people internalize realistic expectations about bodily decline, and help them build financial buffers early. Neither message is glamorous, and neither fits the aspirational tone that has sometimes drawn criticism to the successful-aging concept, which scholars have argued can moralize aging and shift blame onto individuals who fail to meet unrealistic standards. Yet the middle-aged Singaporeans interviewed here offer a grounded counterpoint—a vision of success built not on defying age but on preparing for it, financially, socially, and psychologically, long before it arrives.

Subject of Research: Perspectives on successful aging among middle-aged future older adults in Singapore and their alignment with national aging policy

Article Title: Successful Aging in Singapore: An Exploration of Perspectives Among the Future Older Adults

Article References: Yeo, P. T. J., Tan, R. K. J., & Asano, M. (2026). Successful Aging in Singapore: An Exploration of Perspectives Among the Future Older Adults. Ageing International, 51(3), Article 36. https://doi.org/10.1007/s12126-026-09674-8

Image Credits: AI Generated

DOI: 10.1007/s12126-026-09674-8

Keywords: successful aging, future older adults, Singapore, gerontology, qualitative interviews, financial preparation, ageing policy, physical health, psychological health, Action Plan for Successful Ageing, middle-aged adults, thematic analysis