Abstract
BACKGROUND: Low cardiorespiratory fitness (CRF) has been demonstrated to be associated with increased perioperative morbidity and mortality. However, evidence regarding the effect of prehabilitation on CRF and postoperative outcomes remains inconclusive. METHODS: A systematic review and meta-analysis were conducted in accordance with the PRISMA statement encompassing randomized clinical trials (RCTs) published in PubMed and Web of Science up to June 2025 on the effects of prehabilitation with exercise, measured using the 6-minute walk test, for adult patients undergoing surgery. The primary objective was to examine the effect of prehabilitation based on physical exercise on the preoperative physical condition of adults scheduled to undergo elective surgery, measured as the change in the 6-minute walk distance (6MWD). Factors associated with changes in the 6MWD and the effect of prehabilitation on postoperative CRF were analysed, as were the length of hospital stay and mortality. Effect sizes and their 95% confidence interval (c.i.) were estimated with a random-effects model. RESULTS: Of 107 RCTs screened, 21 were included in the analysis, comprising 1649 patients (828 undergoing prehabilitation) across several specialities, the most prevalent being cardiac (501 patients), colorectal (423 patients), and thoracic surgery (364 patients). The prehabilitation group exhibited a greater improvement in the 6MWD before surgery (mean difference (MD) 29 m; 95% c.i. 14 to 42 m; P < 0.001; I2 = 84%) and in the first month after surgery (MD 22 m; 95% c.i. 0 to 43 m; P = 0.05; I2 = 92%). A greater proportion of patients in the prehabilitation group had a clinically significant improvement in the 6MWD both before (odds ratio (OR) 2.66; 95% c.i. 1.76 to 4.0; P < 0.001; I2 = 53%) and after (OR 2.59; 95% c.i. 1.05 to 6.35; P = 0.04; I2 = 69%) surgery. There were no differences between the groups in length of hospital stay (MD -0.24; 95% c.i. -0.65 to 0.17; P = 0.25; I2 = 25%) or mortality (OR 0.71; 95% c.i. 0.26 to 1.92; P = 0.5; I2 = 0%). CONCLUSION: Prehabilitation involving physical exercise before surgery was associated with an improvement in preoperative CRF. However, no differences were observed between the groups in length of hospital stay or postoperative mortality. The improvement in CRF persists in the postoperative period, suggesting a potential benefit for patient recovery.