The Role of Preoperative Fitness and System Processes in Surgical Outcomes

PREHAB trial data show baseline cardiorespiratory fitness and age strongly predict adherence to preoperative training and track with short‑term postoperative recovery. In colorectal cancer patients awaiting surgery, the analysis focused on preoperative training compliance and short‑term recovery metrics and suggests baseline fitness stratification can signal who will benefit from standard prehabilitation and who may need adapted programs to optimize outcomes.

This secondary analysis of a multicenter randomized trial clarifies that prehabilitation’s benefit is not uniform: it varies substantially by baseline fitness and patient age. The authors treated adherence as a mediator of recovery and modeled predictors of compliance, shifting the emphasis from universal implementation toward targeted preoperative risk stratification to maximize physiologic gain.

Measured preoperative metrics in the PREHAB trial included VO2peak (cardiorespiratory fitness), walking and gait speed, and session-level HIIT intensity and duration. Higher baseline CRF aligned with markedly better training compliance and with improved short‑term recovery. Patients who raised VO2peak after training experienced fewer severe complications and an earlier return to baseline function, supporting routine use of CRF and simple gait/walking speed tests to stratify adherence risk and projected recovery potential.

Age correlated with both response and adherence: younger patients were more likely to complete HIIT sessions and attain clinically meaningful VO2peak gains. That interaction—between initial fitness and program intensity—means older patients and those with low baseline CRF will often need modified, lower‑intensity regimens or additional support to reach adherence and physiologic response.

Operational factors also limited effective prehabilitation. Short lead times to surgery, scheduling delays, and incomplete preoperative assessment or optimization pathways reduced opportunities for training and were associated with higher rates of suboptimal recovery and avoidable cancellations. Earlier candidate identification and protected prehab windows within scheduling workflows are system priorities to preserve the chance for meaningful optimization.