Resistance but not endurance exercise prehabilitation enhances colonic anastomotic healing in a high-risk rat model

Abstract Anastomotic leakage is a major complication after colorectal surgery, which has several risk factors potentially modifiable through preoperative exercise. However, the effectiveness of exercise prehabilitation remains unclear, possibly due to a lack of standardized protocols. Since different training types induce various physiological responses that may alter anastomotic healing, we compared the effects of resistance (RP) and endurance exercise prehabilitation (EP) on surgical outcomes. Rats were divided into sedentary (S), RP, EP with low-risk (LR) and corresponding high-risk (HR) groups undergoing colitis before colonic anastomosis. Maximal exercise performance, magnetic resonance imaging-based body composition, colitis-related clinical and histopathological markers were assessed. Claudin-1, bacterial translocation rate, bursting pressure, hydroxyproline and matrix-metalloproteinase levels were measured to evaluate barrier integrity and anastomotic healing. RP improved muscle strength and body composition more effectively than EP compared to the S group. No differences were observed in any other parameters between the LR groups. Although increased colitis severity in the S-HR compared to the S-LR group was reduced in both exercised-HR groups, improvements in barrier integrity and anastomotic strength were observed only in the RP-HR group. These findings suggest that preoperative resistance training improves high-risk surgical outcomes more effectively, warranting further clinical evaluation as a prehabilitation strategy.