Randomization and masking
Participants were assigned to the intervention or control condition by an independent researcher using a random number generator per block with an allocation of 2:1 in favor of the intervention. Although research assistants, exercise counselors, nor participants were informed of the existence of a control intervention, the trial could not be blinded as the difference in content and aims of the coaching and stretching sessions could not be concealed for participants, exercise counselors, or research assistants.