This randomized controlled trial aims to determine the optimal exercise intensity for improving postoperative recovery in patients with upper gastrointestinal cancer. Participants who have undergone curative surgery will be randomly assigned to high-intensity interval training (HIIT), low-intensity continuous training (LICT), or usual care. The exercise interventions will be performed under supervision three times per week for eight weeks. The primary outcome is peak oxygen uptake (VO₂peak), assessed using cardiopulmonary exercise testing. Secondary outcomes include physical function, body composition, patient-reported outcomes, and biological and mechanistic markers such as inflammatory biomarkers, muscle-related factors, and gut microbiota. This study will also explore potential mechanisms underlying exercise-induced adaptations and their association with clinical outcomes.
This study is a single-center, three-arm randomized controlled trial designed to evaluate the effects of exercise intensity on postoperative recovery in patients with upper gastrointestinal cancer. Patients who have undergone curative surgery for esophageal or gastric cancer will be enrolled 6 ± 2 weeks after surgery and randomly assigned to high-intensity interval training (HIIT), low-intensity continuous training (LICT), or usual care. The exercise intervention consists of supervised aerobic and resistance training performed three times per week for eight weeks. HIIT involves repeated high-intensity intervals interspersed with recovery periods, whereas LICT consists of continuous low-intensity aerobic exercise. The primary outcome is the change in peak oxygen uptake (VO₂peak) from baseline to 8 weeks, assessed using cardiopulmonary exercise testing. Secondary outcomes include measures of physical function, skeletal muscle mass, physical activity, quality of life, and biological and mechanistic outcomes such as inflammatory biomarkers, muscle-related factors, and gut microbiome composition. This study aims to clarify the dose-response relationship of exercise intensity and to explore the physiological mechanisms underlying exercise-induced adaptations in the early postoperative phase.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
171
Supervised aerobic high-intensity interval training combined with resistance training and nutritional counseling. Aerobic training is performed on a cycle ergometer and consists of four sets of 4-minute high-intensity intervals at 80-95% of VO₂peak, interspersed with 3-minute recovery periods at 60% of VO₂peak. Each session includes a 3-minute warm-up and a 3-minute cool-down, with a total duration of 34 minutes. Training is performed three times per week for eight weeks. Resistance training includes chest press, leg extension, leg press, and abdominal exercises using pneumatic resistance machines, consisting of two sets of 20-25 repetitions at approximately 20RM. Nutritional counseling is provided by a registered dietitian once every four weeks for a total of two sessions during the intervention period.
Supervised low-intensity continuous training combined with resistance training and nutritional counseling. Aerobic training is performed on a cycle ergometer at 37-45% of VO₂peak for 28 minutes per session, with a 3-minute warm-up and a 3-minute cool-down, for a total duration of 34 minutes. Training is performed three times per week for eight weeks. Resistance training is identical to the HIIT group and includes chest press, leg extension, leg press, and abdominal exercises using pneumatic resistance machines, consisting of two sets of 20-25 repetitions at approximately 20RM. Nutritional counseling is provided by a registered dietitian once every four weeks for a total of two sessions during the intervention period.
Kansai Medical University
Hirakata, Osaka, Japan
NOT_YET_RECRUITINGKansai Medical University
Hirakata, Osaka, Japan
RECRUITINGPeak oxygen uptake (VO₂peak)
Cardiorespiratory fitness will be assessed using symptom-limited cardiopulmonary exercise testing (CPET) on a cycle ergometer under medical supervision with continuous breath-by-breath gas analysis. After a 4-minute unloaded warm-up, workload is increased by 10-20 W/min depending on patient condition, with participants cycling at 50 rpm until volitional exhaustion. The test is terminated when cadence falls below 40 rpm, at physician discretion, or at patient exhaustion, followed by a 2-minute cool-down at 20 W. Continuous 12-lead ECG, blood pressure, and oxygen saturation are monitored during testing. VO₂peak is defined as the highest 30-second averaged oxygen uptake immediately prior to exhaustion. Peak workload, peak heart rate, and oxygen uptake at ventilatory threshold are also recorded.
Time frame: Baseline and 8 weeks after the intervention
Handgrip strength
Handgrip strength will be measured using a standard adjustable-handle dynamometer (InGrip, InBody Japan Inc., Tokyo, Japan). Measurements will be performed in a standing position with arms at the side. Two maximal voluntary efforts will be recorded for each hand, and the highest value will be used (kg) as the outcome measure.
Time frame: Baseline and 8 weeks after the intervention
Chair stand test
Lower-limb muscle strength will be assessed using the 30-second chair stand test (CS-30). Participants will perform as many sit-to-stand repetitions as possible within 30 seconds without using their hands from a standard chair (approximately 43 cm seat height). The total number of completed stands will be recorded. Extended versions (CS-60 and CS-90) will be derived as endurance indicators.
Time frame: Baseline and 8 weeks after the intervention
Short Physical Performance Battery (SPPB)
Physical performance will be assessed using the SPPB, consisting of standing balance, gait speed, and chair stand tests. Each component is scored and summed to produce a total score ranging from 0 (worst performance) to 12 (best performance).
Time frame: Baseline and 8 weeks after the intervention
Skeletal muscle mass
Skeletal muscle mass will be measured using a segmental multi-frequency bioelectrical impedance analyzer (InBody770, InBody Japan Inc., Tokyo, Japan).
Time frame: Baseline and 8 weeks after the intervention
Physical activity (Japanese version of the International Physical Activity Questionnaire-Short Form)
Physical activity will be assessed using the Japanese version of the International Physical Activity Questionnaire-Short Form (IPAQ-SF). The IPAQ-SF provides an estimate of total physical activity expressed in metabolic equivalent task minutes per week (MET-min/week), calculated based on walking, moderate, and vigorous physical activities. The total score ranges from 0 to theoretically unlimited values, with higher scores indicating greater levels of physical activity.
Time frame: Baseline and 8 weeks after the intervention
Total exercise volume
Total exercise volume will be calculated as the cumulative prescribed aerobic and resistance exercise over the 8-week intervention period. Aerobic exercise volume will be based on prescribed duration and intensity (HIIT or LICT protocols). Resistance training volume will be calculated by taking into account both the number of sets and repetitions performed across all prescribed exercises during the intervention period.
Time frame: During the 8-week intervention period
Exercise adherence
Exercise adherence will be defined as the proportion of completed supervised exercise sessions and compliance with the prescribed exercise protocol, expressed as a percentage.
Time frame: During the 8-week intervention period
Patient-reported outcomes
Health-related quality of life and symptoms will be assessed using the EORTC QLQ-C30. Scores for functional scales, symptom scales, and global health status will be linearly transformed to a 0-100 scale.
Time frame: Baseline and 8 weeks after the intervention
Blood biomarkers
Serum levels of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), irisin, SPARC, and adrenaline will be measured.
Time frame: Baseline and 8 weeks after the intervention
Gut microbiome
Gut microbiome composition will be analyzed using 16S rRNA sequencing of stool samples to assess alpha diversity, beta diversity, and taxonomic composition.
Time frame: Baseline and 8 weeks after the intervention
Urinary urea nitrogen
Urinary urea nitrogen (UUN) as an indicator of protein metabolism and nutritional status.
Time frame: Baseline and 8 weeks after the intervention
Adverse events
All adverse events will be systematically recorded throughout the study period.
Time frame: During the 8-week intervention period
Pneumonia
Pneumonia will be defined as new or progressive infiltrates on chest radiographs or CT scans, as well as meeting at least two of the following three criteria: body temperature greater than 38°C, leukopenia or leukocytosis (white blood cell count less than 4 × 10⁹/L or greater than 10 × 10⁹/L), and purulent sputum.
Time frame: During the 8-week intervention period
Readmission
Unplanned hospital readmission will be defined as any admission occurring after discharge and within the study period, extracted from medical records.
Time frame: During the 8-week intervention period
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