This pilot demonstrated that a supervised outpatient physical exercise training program for individual patients with locally advanced resectable rectal cancer during NACRT is feasible for a large part of the patients, safe and seems able to prevent an often seen decline in physical fitness during NACRT. A larger study into the cost-effectiveness of this approach is warranted.

There is an association between preoperative parameters and postoperative outcomes in patients with colorectal cancer scheduled for resection. Patients benefit from an optimal preoperative physical fitness level. Specific interventions can target this physical fitness level.

Steep ramp test (SRT) performance provides an estimation of preoperative aerobic fitness that is associated with postoperative outcomes. Patients with a better SRT-estimated aerobic fitness are less likely to develop postoperative complications and more likely to experience a shorter time to recovery. The SRT might be a useful and clinically accessible tool in preoperative risk assessment to identify patients at risk of postoperative morbidity and who might benefit from preoperative exercise interventions.

Background and Objectives To assess the association of preoperative aerobic fitness and body composition variables with a patient's resilience to the development and impact of postoperative complications after elective colorectal cancer (CRC) surgery. Methods Preoperative aerobic fitness was assessed by steep ramp test performance. Preoperative body composition was assessed by muscle mass and density determined from preoperative computed tomography scan analysis at the L3‐level. Complication development and severity was graded according to Clavien‐Dindo. Complication impact was assessed by the time to recovery of physical functioning after complications. Multivariable logistic regression analyses adjusted for age, sex, comorbidities and tumour location was performed. Results Of 238 included patients, 96 (40.3%) developed postoperative complications. Better preoperative aerobic fitness decreased the likelihood to develop complications, independent of muscle mass (odds ratio [OR]: 0.55, 95% confidence interval [CI]: 0.35−0.85) or muscle density (OR: 0.57, 95% CI: 0.36−0.89). A prolonged time to recovery following complications was associated with lower preoperative muscle density (OR: 4.14, 95% CI: 1.28−13.41), independent of aerobic fitness. Conclusions Lower aerobic fitness increases the risk of complication development, while low muscle density seems associated with a prolonged recovery from complications. Aerobic fitness and muscle density could be valuable additives to preoperative risk assessment.