Reference values and prediction equations for six-minute walk distance and stair-climbing test performance in apparently healthy Ethiopian adults

The six-minute walk test (6MWT) and stair-climbing test (SCT) are simple and practical measures of functional exercise capacity. Interpretation of performance requires appropriate population-specific reference values and prediction equations. However, reference data for apparently healthy Ethiopian adults remain limited. This study aimed to establish reference values and develop prediction equations for six-minute walk distance (6MWD) and SCT performance among apparently healthy Ethiopian adults. A community-based cross-sectional study was conducted among 139 apparently healthy Ethiopian adults aged 18–55 years. Demographic and anthropometric characteristics were collected using standardised procedures. Participants performed the 6MWT and SCT according to standardised protocols. Descriptive statistics and percentile distributions were used to characterise exercise-test performance. Pearson correlation analysis was performed to assess associations between demographic and anthropometric characteristics and exercise-test performance. Multivariable linear regression analyses were conducted to identify independent predictors of 6MWD and SCT performance and to develop prediction equations. The study included 139 participants, comprising 82 (59.0%) men and 57 (41.0%) women, with a mean age of 26.7 ± 7.1 years. The overall mean 6MWD was 587.1 ± 72.3 m, and the mean SCT completion time was 0.656 ± 0.098 min. Men achieved a significantly greater 6MWD than women (613.4 ± 68.3 m vs. 549.3 ± 60.6 m; p < 0.001) and completed the SCT in significantly less time (0.624 ± 0.084 min vs. 0.700 ± 0.100 min; p < 0.001). Age was negatively correlated with 6MWD ( r = − 0.224, p = 0.008) and positively correlated with SCT completion time ( r = 0.322, p < 0.001). Height and BMI were significantly associated with 6MWD, whereas weight and BMI were positively associated with SCT completion time. In multivariable analyses, age and sex were independent predictors of both outcomes. The 6MWD model explained 25.5% of the variance (adjusted R² = 0.233), while the SCT model explained 24.9% (adjusted R² = 0.227). This study provides population-specific reference values and prediction equations for 6MWD and SCT performance among apparently healthy Ethiopian adults. Significant sex differences were observed in both exercise tests, with men demonstrating greater walking distances and faster stair-climbing performance. Age and sex were consistent independent predictors of performance, whereas the independent contributions of anthropometric variables were less consistent after adjustment. These findings provide locally derived reference data that may support interpretation of functional exercise performance in Ethiopian adults. Further studies involving larger and geographically diverse populations, with external validation of the prediction equations, are warranted.