Table 1.

Main characteristics of the included studies

Reference	Design	Patients at baseline	Age	Disease/prehabilitation phase	Inclusion/exclusion criteria	Main outcome parameters/questionnaires	Conclusion
Bhatia C, 2019 [23]	Randomized controlled trial	151	HIIT: 64 (13) UC: 64 (10)	Non-small cell lung carcinoma, stage; presurgical	Incl.: NSCLC, stage IIIA or less Excl.: contraindications for cardiopulmonary exercise testing (e.g., uncontrolled cardiac disease, severe pulmonary hypertension, uncontrolled asthma), limitations to adhere to prehabilitation (e.g., cycling difficulties)	Cardiorespiratory fitness (VO2peak), 6MWT, oxygen saturation, leg fatigue, and dyspnea (BORG scale)	Short-term HIIT was feasible and safe in preoperative setting and increased cardiorespiratory fitness
Egegaard T, 2019 [17]	Randomized controlled trial	13	HIIT: 64 (5.8) UC: 65 (4.7)	Non-small cell lung carcinoma; during concomitant radiotherapy	Incl.: NSCLC, age ≥ 18 years, stage IIIA-IV, WHO performance status 0–1 with concomitant chemoradiotherapy Excl.: any symptoms or circumstances that advise against physical activity; symptomatic heart disease (e.g., arrhythmia or myocardial infarction within the last 3 months)	Cardiorespiratory fitness (VO2peak, WRpeak), activity data (steps), pulmonary function, HADS, FACT-L, 6MWT, IPAQ-L	High intensity was feasible, safe, and well tolerated during concomitant chemoradiotherapy; no significant differences within or between groups in any secondary outcome
Mijwel S, 2019 [15]	Randomized controlled trial	175	HIIT/RT: 52.7 (10.3) HIIT/MICT: 54.4 (10.3) UC: 52.6 (10.2)	Breast cancer; during concomitant chemotherapy	Incl.: women with breast cancer, aged 18–70 years, stage I–IIIa, planned to receive adjuvant chemotherapy Excl.: advanced disease, heart or lung disease, cognitive dysfunction	Cardiorespiratory fitness (VO2peak), PFS, EORTC-QLQ C30, MSAS, muscle strength, return to work	Intervention groups showed beneficial effects on cancer-related fatigue, symptoms, and muscle strength, 12 months following the commencement of chemotherapy
Banerjee S, 2017 [36]	Randomized controlled trial	60	HIIT: 71.6 (6.8) UC: 72.5 (8.4)	Bladder cancer; presurgical	Incl.: bladder cancer patients listed for radical cystectomy (± neoadjuvant chemotherapy) Excl.: patients with urinary diversion for benign disease, patients meeting current physical activity guidelines (≥ 150 min of moderate intensity per week)	Cardiorespiratory fitness (VO2peak, AT, WRpeak), feasibility, Clavien Dindo classification, LOS	HIIT was feasible and well tolerated and improved cardiopulmonary fitness
Karenovics W, 2017 [24]	Randomized controlled trial	151	HIIT: 64 (13) UC: 64 (10)	Non-small cell lung carcinoma; presurgical	Incl.: proven or suspected NSCLC, stage IIIA or less, awaiting lung resection surgery Excl.: any contraindication for CPET (e.g., uncontrolled cardiac disease, severe pulmonary hypertension, limitations impeding cycling); inability to adhere to a rehabilitation program	cardiorespiratory fitness (VO2peak, WRpeak), pulmonary function test, survival (1y FU)	Preoperative rehabilitation with HIIT does not improve pulmonary function and aerobic capacity 1 year after lung cancer resection, survival after 1 year was equal, postop pulmonary complications less in HIIT
Dunne DFJ, 2016 [34]	Randomized controlled trial	38	HIIT: 61 (56–68) UC: 62 (53–72)	Colorectal liver metastasis patients, presurgical	Incl.: resectable colorectal liver metastasis, age ≥ 18 years, partake in cycle-based exercise, complete the exercise program before the proposed surgery date, at least 4 weeks of prehabilitation Excl.: pre-existing chronic liver disease, recruitment to the study must not result in delayed surgical care	cardiorespiratory fitness (VO2peak, AT, WRpeak), SF-36	HIIT was feasible and safe, the intervention reduced fatigue, improved vitality, aerobic capacity, muscular strength, physical and functional activity, emotional well-being, but not quality of life
West MA, 2015 [35]	Non-randomized controlled trial	39	HIIT: 64 (45–82) UC: 72 (62–84)	Non-metastatic locally advanced rectal cancer, presurgical	Incl.: locally advanced resectable rectal cancer, age ≥ 18 years, stage T2/N+, no distant metastasis, WHO performance status < 2, undergoing NACRT Excl.: nonresectable disease, inability to perform CPET or bicycle exercise, patients who declined surgery or NACRT, patients who received non-standard NACRT	Cardiorespiratory fitness (VO2peak, LT, WRpeak), spirometry, MRI staging	Chemoradiotherapy before rectal cancer surgery reduced physical fitness; however, a 6-week exercise intervention was feasible and returns fitness to baseline levels
Adamsen L, 2009 [16]	Randomized controlled trial	269	HIIT: 47.2 (10.7) UC: 47.2 (10.6)	Non-metastatic cancer patients undergoing chemotherapy	Incl.: a diagnosis of cancer, aged 18–65 years, at least one cycle of chemotherapy for advanced disease or as adjuvant treatment, WHO performance status of 0 or 1 Excl.: brain or bone metastases, thrombocytopenia (< 50 × 109/l), myocardial infarction within the past 3 months, uncontrolled hypertension (diastolic pressure > 95 mmHg)	Cardiorespiratory fitness (VO2peak), EORTC-QLQ C30, Medical Outcomes, SF-36, Leisure Time Physical Activity Quest., muscular strength	HIIT was feasible and safe, the intervention reduced fatigue, improved vitality, aerobic capacity, muscular strength, physical and functional activity, emotional well-being, but not quality of life

Incl inclusion, Excl exclusion, BL baseline, FU follow-up, AT anaerobic threshold, LT lactate threshold, WRpeak work rate peak, EORTC-QLQ C30, European Organisation for Research and Treatment of Cancer/Core Quality of Life Questionnaire, LOS length of stay, PFS Piper Fatigue Scale, MSAS Memorial Symptom Assessment Scale, HADS Hospital Anxiety and Depression Scale, IPAQ-L International Physical Activity Questionnaire, NSCLC non-small cell lung carcinoma, CPET cardiopulmonary exercise testing, NACRT neoadjuvant chemoradiotherapy