Methodological Considerations for Future Research on Physical Activity and Frailty

We read with great interest the study by Mayo et al,1 which examined the associations among moderate-to-vigorous physical activity (MVPA), resistance training (RT), frailty, and mortality. Although this study provides valuable insights into sex- and age-specific differences, we would like to highlight 3 methodological limitations that should be addressed in future research to strengthen the evidence base.