Study Procedures

Eligible patients were randomly assigned 1:1 to receive a 4-week prehabilitation program (Prehab group) or a 4-week postoperative rehabilitation program (Rehab group). This design was chosen based on previous trial experience,²⁴ because it limits the risk of poor enrollment and attrition bias (ie, missing follow-up appointments by patients in the control group) by offering interventions to both groups. Randomization was achieved via computer-generated random numbers composed of 12 blocks of 10. Allocations were placed in sealed, opaque, consecutively numbered envelopes by an independent researcher (G.B.-D.). Allocation was concealed until the baseline assessment was completed, when envelopes were opened in numerical order. Outcome assessors (G.B.-D. and R.A.), surgeons (S.L., M.B., B.S., P.C., G.G., and N.M.), and statisticians (J.F.F.) were blinded to group assignment. Owing to the nature of the intervention, it was not possible to blind patients or intervention staff. To minimize performance bias, patients were informed that we were comparing 2 types of perioperative exercise programs, and one was not presented as potentially superior to the other.