Exercise and Cardiorespiratory fitness Improvement through supervised TraINinG in patients undergoing surgery for Upper GastroIntestinal cancer (EXCITING-UGI): study protocol for a randomized controlled trial

Abstract

Upper gastrointestinal cancers, including esophageal and gastric cancers, are associated with substantial postoperative functional decline despite curative surgery. Particularly, cardiorespiratory fitness decreases markedly after surgery, and such decrease is associated with poor clinical outcomes. Thus, it serves as a surrogate marker of prognosis. Exercise has been shown to improve cardiorespiratory fitness in patients with cancer; however, the optimal exercise intensity in the early postoperative phase remains unclear. High-intensity interval training (HIIT) may provide greater improvement, whereas low-intensity continuous training (LICT) may be more feasible for patients with reduced physical function. This study aims to compare the effects of HIIT and LICT on the postoperative recovery of patients with upper gastrointestinal cancer. The Exercise and Cardiorespiratory fitness Improvement through supervised TraINinG in patients undergoing surgery for Upper GastroIntestinal cancer (EXCITING-UGI) study is a single-center, three-arm randomized controlled trial in patients with upper gastrointestinal cancer who undergo curative surgery. The participants are randomly allocated to the HIIT, LICT, or control group. Participants in the intervention groups undertake an 8-week supervised exercise program that combines aerobic and resistance training three times per week. Aerobic exercise is prescribed based on peak oxygen uptake (VO₂peak), with HIIT performed at 80–95% VO₂peak and LICT at 37–45% VO₂peak. All participants receive standard nutritional counseling. The primary outcome measure is cardiorespiratory fitness, measured by VO₂peak. The secondary outcomes are physical function, body composition, activity and behavior, patient-reported outcomes, biological and mechanistic outcomes, and safety and clinical outcomes. Assessments are conducted at baseline and at 4 and 8 weeks post-intervention. This randomized controlled trial will compare the effects of HIIT and LICT on the postoperative recovery of patients with upper gastrointestinal cancer. By setting cardiorespiratory fitness as the primary outcome measure, this study may provide clinically relevant evidence for optimizing exercise intensity in the early postoperative phase. Additionally, the inclusion of biological outcomes may offer insights into the mechanisms underlying exercise-induced recovery. The findings are expected to inform evidence-based intensity-specific exercise strategies for this population. NCT07561840.