​randomization.​com). The three groups were (1) twice a week balance and tone group (no external resistance other than body weight, BT), (2) once a week resistance training program (RT1), and (3) twice a week resistance training program (RT2). Treatment allocation was concealed, and the measurement team and bone data analyst were blinded to group allocation. The exercise intervention ran for 1 year (April 2007–April 2008) and was based on the KU-60019 principles of periodization with four terms, each lasting approximately

3 months in duration. Although the intervention was group based, exercises were individualized and the program was progressive so that the exercises in the fourth term built upon the foundation of the previous three terms. All exercise classes were delivered in groups of approximately eight to ten participants, with two certified BAY 63-2521 price fitness instructors

and one class assistant per www.selleckchem.com/products/R406.html class leading each class. All the three groups (BT, RT1, RT2) had similar warm-up and cool-down sessions. The participants in RT1 and RT2 completed eight strengthening exercises for the upper and lower extremities using the Keiser air pressure resistance equipment (Keiser Sports Health Equipment, Fresno, CA) at each session. The participants in RT1 and RT2 completed a one repetition maximum (1RM) at the beginning of each of the four terms, and resistance training was targeted at 8RM; that

is, at each session, participants were asked to complete two sets of each exercise at a weight heavy enough that they were able to complete eight repetitions. Every 2 weeks, the exercise instructors increased participants’ weights for each exercise if it was appropriate to do so. The BT group completed balance and tone exercises only using the body weight as the resistance. Participants were requested to maintain their usual physical activity routine outside of the classes. Sample size This was an RCT investigating the effect of resistance Forskolin training on executive function [21]. The size of the trial (52 participants/group) was based on the Stroop test, a measure of selective attention [22], and the trial was designed to have 80 % power to detect differences between groups. During the trial design phase, we also determined if we had adequate power to detect differences between groups for CovBMD; a change prediction of 1 % of tibial cortical density over 1 year for the RT2 group and −1 % for the BT group. Assuming a 20 % attrition rate and using an alpha level = 0.05 (two-sided), we determined that 30 participants per group would provide >80 % power to detect a difference between groups. Adverse events We monitored for any adverse events (e.g., pain, discomfort) at each session; participants were requested to report any events to the instructors who regularly communicated with the research staff.