Exercise plus daily movement linked to lowest eight-year risk of mobility decline in Japanese cohort

Mobility loss often begins decades before anyone notices it, and a new eight-year study of more than 21,000 Japanese adults suggests that the habits people report in a routine health checkup may help flag who is most at risk. Researchers found that middle-aged and older adults who combined habitual exercise with sufficient daily physical activity had the lowest cumulative incidence of locomotive syndrome, a Japanese clinical construct that captures early mobility impairment before it progresses to disability.

The retrospective cohort study, published in the European Review of Aging and Physical Activity, drew on annual health checkups at a private clinic in Saitama City between 2016 and 2024. Of 34,851 people who attended the baseline checkup in 2016, 21,339 were included after the researchers excluded those with missing locomotive syndrome risk test data, missing activity information, prevalent locomotive syndrome at baseline, or no follow-up assessment. The participants were aged 21 to 84 years, with a median age of 48, and 40 percent were women.

Locomotive syndrome is a concept proposed by the Japanese Orthopaedic Association to describe reduced mobility caused by musculoskeletal impairment, characterized by declines in walking ability, balance, and physical function. It is detected with simple performance tests and a self-administered questionnaire: the two-step test, which measures maximal stride length relative to height; the stand-up test, which assesses the ability to rise from chairs of varying heights; and the 25-item Geriatric Locomotive Function Scale, a questionnaire covering daily activities, pain, social function, and mental health with scores from 0 to 100. Participants were classified as having locomotive syndrome if they met at least one criterion, including a two-step test value below 1.3, inability to stand on one leg from a 40-centimeter chair, or a questionnaire score of 7 or higher. Earlier research has shown that mobility decline measured this way predicts future care-need certification.

At baseline, exercise habits were assessed with a single yes-or-no question asking whether participants had done light-to-moderate exercise producing mild sweating for at least 30 minutes per session, at least twice a week, for at least one year. Daily physical activity was assessed by asking whether they walked or performed an equivalent level of activity for at least one hour per day. These items come from Japan’s national Specific Health Checkup program. Combining the two answers produced four groups: inactive, daily activity only, exercise only, and both. Just over half of the cohort, 53 percent, fell into the inactive group, while 15 percent reported both behaviors.

Over eight years, 7,183 participants, or 34 percent, developed incident locomotive syndrome. The researchers estimated cumulative incidence with Kaplan-Meier methods and compared the four activity groups within three age strata: 39 years and younger, 40 to 64, and 65 and older. In the middle-aged group, cumulative incidence at eight years fell in a stepwise pattern from 0.45 in the inactive group to 0.37 among those reporting both exercise and daily activity, a difference that was statistically significant with a log-rank P value below 0.001. In a multivariable Cox model adjusted for body mass index, metabolic syndrome, anemia, smoking, alcohol consumption, dietary habits, and sleep, the combined-activity group had the lowest risk, with a hazard ratio of 0.79 and a 95 percent confidence interval of 0.72 to 0.85.

The pattern was similar, and stronger, among adults aged 65 and older. Cumulative incidence ranged from 0.71 in the inactive group to 0.55 in the most active group, and the fully adjusted hazard ratio for the combined group was 0.70 with a 95 percent confidence interval of 0.56 to 0.86. In this older stratum, only the combination of exercise and daily activity remained statistically significant after full adjustment, which the authors suggest may reflect the smaller sample of 1,151 older participants and greater heterogeneity in health status. Among adults aged 39 and younger, the separation of incidence curves was modest and did not reach statistical significance, with an overall model P value of 0.22 in the fully adjusted analysis, a pattern consistent with lower absolute risk and greater functional reserve in early adulthood.

Across all age groups, the ordering of risk was consistent: the inactive group had the highest incidence, groups reporting one behavior had intermediate risk, and the group reporting both had the lowest. Notably, a pooled Cox model including an interaction term between age group and activity pattern found no statistically significant interaction, with a P value of 0.99, suggesting that the magnitude of the association did not differ measurably across the three life stages even though statistical significance within strata varied.

The test-specific analyses added a subtle but clinically relevant insight. Cumulative incidence was highest when locomotive syndrome was defined by the self-reported questionnaire, followed by the stand-up test and then the two-step test. The authors interpret this ordering as evidence that subjective functional decline, including perceived mobility limitation and pain-related restriction, tends to precede measurable performance-based impairment. If confirmed, patient-reported instruments such as the Geriatric Locomotive Function Scale could serve as early intervention targets, complementing objective tests that may be subject to ceiling effects in relatively healthy, younger populations.

The findings come with important caveats. Both exposures were captured with brief binary self-report items at a single baseline time point, so misclassification and changes in behavior during follow-up cannot be excluded, and the study could not evaluate dose-response relationships or specific activity domains. The lowest risk among people reporting both behaviors may simply reflect a greater overall volume of physical activity rather than any specific type of exercise. The cohort consisted primarily of urban health checkup attendees, and excluded participants were older, more often physically inactive, and had less favorable lifestyle profiles, raising the possibility of healthy volunteer bias. Unmeasured confounding from factors such as depressive symptoms, sarcopenia, and social circumstances also cannot be ruled out, and because assessments occurred only at periodic checkups, the exact onset of incident locomotive syndrome was not directly observed.

Even with those limitations, the study offers a pragmatic message for prevention. Mobility decline warranting preventive attention appears to begin in midlife, not only in older age, and simple two-question screening items routinely collected in health checkups were associated with long-term risk over eight years. When structured exercise is difficult to fit into a schedule, the authors note that consciously increasing movement in daily routines, such as walking during commuting, taking stairs, and moving during work or household tasks, may help preserve mobility. Conversely, when daily opportunities for movement are limited, scheduling regular walks or brief home-based exercise sessions may partially compensate. Promoting both an active daily lifestyle and habitual exercise, the study concludes, appears most strongly associated with supporting long-term mobility across adulthood.

Subject of Research: Age-specific associations of self-reported exercise habits and daily physical activity with the eight-year cumulative incidence of locomotive syndrome in a Japanese health checkup cohort

Article Title: Exercise, daily physical activity, and age-specific cumulative incidence of mobility decline: an 8-year cohort study of locomotive syndrome

Article References: Yamaguchi, S., Yamada, K., Moriyama, M., Arai, T., Morita, Y., Ishibashi, H., Ohe, T., Ohtori, S., & Nakagawa, R. (2026). Exercise, daily physical activity, and age-specific cumulative incidence of mobility decline: an 8-year cohort study of locomotive syndrome. European Review of Aging and Physical Activity, 23(1), Article 34. https://doi.org/10.1186/s11556-026-00424-y

Image Credits: AI Generated

DOI: 10.1186/s11556-026-00424-y

Keywords: locomotive syndrome, mobility decline, physical activity, exercise habits, cohort study, aging, health checkup, GLFS-25, two-step test, stand-up test, Japan, middle age