Randomized clinical trial Randomized clinical trial of prehabilitation in colorectal surgery F. Carli 1 , P. Charlebois 2 , B. Stein 2 , L. Feldman 2 , G. Zavorsky 5 , D. J. Kim 3,4 , S. Scott 3,4 and N. E. Mayo 3,4 Departments of 1 Anesthesia and 2 Surgery and 3 Division of Clinical Epidemiology, McGill University Health Centre, 4 School of Physical and Occupational Therapy, McGill University, Montreal, Quebec, Canada, and 5 Department of Pharmacological and Physiological Science, Saint Louis University, Saint Louis, Missouri, USA Correspondence to: Dr F. Carli, Department of Anesthesia, McGill University Health Centre, 1650 Cedar Avenue, Room D10·144, Montreal, Quebec, Canada H3G 1A4 (e-mail: franco.carli@mcgill.ca) Background: ‘Prehabilitation’ is an intervention to enhance functional capacity in anticipation of a forthcoming physiological stressor. In patients scheduled for colorectal surgery, the extent to which a structured prehabilitation regimen of stationary cycling and strengthening optimized recovery of functional walking capacity after surgery was compared with a simpler regimen of walking and breathing exercises. Methods: Some 112 patients (mean(s.d.) age 60(16) years) were randomized to either the structured bike and strengthening regimen (bike/strengthening group, 58 patients) or the simpler walking and breathing regimen (walk/breathing group, 54 patients). Randomization was done at the surgical planning visit; the mean time to surgery available for prehabilitation was 52 days; follow-up was for approximately 10 weeks after surgery. Results: There were no differences between the groups in mean functional walking capacity over the prehabilitation period or at postoperative follow-up. The proportion showing an improvement in walking capacity was greater in the walk/breathing group than in the bike/strengthening group at the end of the prehabilitation period (47 versus 22 per cent respectively; P = 0·051) and after surgery (41 versus 11 per cent; P = 0·019). Conclusion: There was an unexpected benefit from the recommendation to increase walking and breathing, as designed for the control group. Adherence to recommendations was low. An examination of prehabilitation ‘responders’ would add valuable information. Registration number: NCT00227526 (http://www.clinicaltrials.gov). Paper accepted 9 March 2010 Published online 25 May 2010 in Wiley InterScience (www.bjs.co.uk). DOI: 10.1002/bjs.7102 Introduction Despite advances in methods of earlier detection, diagnosis, surgical technology, anaesthesia and perioperative care, which have made surgery safer, more effective and applicable to a wide range of the population, there is still a proportion of patients who undergo surgery with suboptimal recovery 1,2 . There is no ‘gold standard’ for measuring recovery, considering that this term means to get back to or regain a normal condition. Using this definition, it would follow that some aspects of preoperative function be included in the measurement of recovery 3–8 . When the impact of abdominal surgery was evaluated using measures of functional exercise capacity, two-thirds of people were shown not to have recovered to preoperative levels even 9 weeks after surgery 8,9 . Traditionally, efforts have been made to improve the recovery process by intervening in the postoperative period 10 . However, this may not be the most opportune time because many patients and surgeons are concerned about perturbing the healing process. In addition, patients may be depressed and anxious as they may be awaiting additional treatments for the underlying condition. The preoperative period may be a more emotionally salient time to intervene with regard to the factors that contribute to recovery as, beyond physical benefits, active engage- ment of the individual in the preparation process is likely Copyright  2010 British Journal of Surgery Society Ltd British Journal of Surgery 2010; 97: 1187–1197 Published by John Wiley & Sons Ltd