Physical activity is a key determinant of health in older adults, enhancing physical and mental well-being, reducing mortality risks, and improving overall functioning. However, many older adults remain insufficiently active despite the World Health Organization’s recommendations of at least 150 minutes of moderate-intensity physical activity per week.

This study aimed to explore correlations between physical activity levels measured by subjective (IPAQ) and objective (activity monitors) assessments in older adults. Additionally, the study sought to identify functional tests that could correlate with activity levels and establish cut-off points for these tests.

Participants included 90 older adults who were assessed using the IPAQ, an activity monitor, and functional tests such as the 6-Minute Walking Test (6MWT), Timed Up and Go (TUG), and Berg Balance Scale (BBS). Data were analyzed using Spearman’s correlation and Receiver Operating Characteristics (ROC) analysis.

No significant correlation was found between the IPAQ (self-reported) and activity monitor data (objective). The activity monitor showed lower levels of physical activity than the IPAQ, suggesting potential overestimation in self-reports. A moderate correlation was observed between the 6MWT and moderate-to-vigorous physical activity (MVPA) levels. ROC analysis of the 6MWT revealed an Area Under the Curve (AUC) of 0.83, indicating good discriminatory capacity with a cut-off of 273.9 meters (walking speed of 0.76 m/s) to identify those achieving the recommended 150 minutes of MVPA.

Objective and subjective physical activity levels were not correlated in older adults, who may overestimate their physical activity levels, with self-reported activity levels higher than objective ones. Clinical testing can add value to assessing physical activity levels, with the 6MWT being correlated with objective measures. Further research is recommended to validate the 6MWT across different populations and health conditions to expand its use in clinical settings.

Clinicians may not rely solely on physical activity levels reported by older adults. The 6MWT could be a practical tool for assessing physical activity in them, offering valuable insights for rehabilitation programs and complementing subjective assessments.