Randomization and Masking
Participants were randomly assigned into arms in a 1:1:1:1:1 ratio using a central computer-generated random number sequence in blocks of 5: arm 1 (aerobic-resistance exercise, cognitive training, and vitamin D); arm 2 (exercise, cognitive training, and placebo vitamin D); arm 3 (exercise, sham cognitive training, and vitamin D); arm 4 (exercise, sham cognitive training, and placebo vitamin D); and arm 5 (balance and toning exercise, sham cognitive training, and placebo vitamin D). A research pharmacist assigned vitamin D or placebo capsules as kits in compliance with the randomization list(s).Arm allocation was not disclosed to participants, who were asked not to discuss the intervention during training sessions. Outcome assessors were masked to allocation and not involved in the interventions.