Grouping
This study was a single-blind randomized controlled trial. Stratified randomization was used for grouping. After stratified by age bracket (every 20 years was an age bracket) and sex, a computer random number generator was used to divide the participants randomly into three groups as follows: aerobic exercise intervention (A), resistance exercise intervention (R), and control (C). Intervention and statistics staff were aware of the groupings, but none of the participants was aware of the presence of the other groups (single-blind experimental design). The sample size estimation formula for the comparison of multiple samples was used to estimate the sample size (