High-intensity interval training produces a significant improvement in fitness in less than 31 days before surgery for urological cancer: a randomised control trial

Urological malignancies such as prostate, kidney, and bladder cancers are common and their surgeries carry high complication rates. Survivors frequently experience fatigue, reduced physical function, and diminished quality of life, with many not returning to baseline function for months after surgery. Cardiopulmonary exercise testing (CPET) is the gold standard to assess cardiorespiratory fitness (CRF) and identifies patients at higher risk of postoperative complications. Prior work has defined a minimal clinically important difference (MCID) for anaerobic threshold (VO2AT) of 1.5–2.0 ml/kg/min; achieving this MCID has been associated with reduced postoperative complications. Given UK cancer pathways mandate first treatment within 31 days of the decision to treat, there is a limited window for prehabilitation. High-intensity interval training (HIIT) can improve CRF over shorter periods than moderate continuous training and may be suitable for preoperative prehabilitation in older cancer patients. The primary objective was to determine whether patients with urological malignancy could achieve the MCID in VO2AT within 31 days using HIIT. Secondary objectives included effects on blood pressure, body composition, muscle architecture, and patient acceptability.

Prehabilitation aims to increase physiological reserve before surgery and can improve postoperative functional fitness. In urology, prior prehabilitation studies have largely focused on urologic-specific complications (e.g., urinary incontinence) rather than global physiological parameters linked to outcomes such as CRF, skeletal muscle mass, and body composition. Moderate continuous training often requires longer durations than available before cancer surgery. HIIT has been shown to effectively improve CRF in healthy and clinical populations, including some cancer cohorts (lung, bowel, breast), within shorter time frames. Time efficiency is a key adherence factor in older populations, suggesting low-volume HIIT protocols may be most feasible.

Design: Parallel-group randomised controlled trial (1:1 allocation) conducted at a large secondary referral UK hospital and associated university exercise laboratory. Recruitment ran from August 2016 to June 2018. Ethical approval: NHS REC reference 16/EM/0075; IRAS Project ID 19141. Trial registration: ClinicalTrials.gov NCT02671617. Conducted in accordance with CONSORT guidelines. Participants: Consecutive patients >65 years scheduled for major urological surgery following multidisciplinary team (MDT) decision to operate. Patients were approached only if timelines allowed baseline assessment, ≥10 HIIT sessions, and reassessment within 72 hours before surgery. Inclusion and safety screening conformed to American Thoracic Society CPET eligibility guidelines. Written informed consent obtained. Randomisation and blinding: Computer-generated random permuted block sizes with stratification by age and gender. Allocation concealment via opaque sealed envelopes at first study visit. Due to intervention nature, participants were not blinded; outcome assessors were blinded to group and time-point. Interventions: Both groups instructed to maintain habitual physical activity and diet. Control (CON): Standard care with two assessment sessions 4 weeks apart. HIIT: Up to 12 fully supervised sessions over <31 days (3–4 sessions/week; no weekends) on a cycle ergometer in an individual, lab-based setting supervised by a medically qualified doctor. Each session: 2-min unloaded warm-up; five 1-min intervals at 100–115% of maximal wattage achieved during baseline CPET; 2-min unloaded recovery at end. Progression: ~10% increase in wattage mid-way (after ~6 sessions) to maintain target intensity. Adherence defined a priori as completing ≥10 sessions. Target intensity verified by achieving >85% predicted maximum heart rate during sessions. Assessments: At baseline and reassessment (≤72 h pre-op): Questionnaires (Dukes Activity Status Index; EQ-5D-5L; Warwick Edinburgh Mental Wellbeing Scale). Body composition by DXA. Vastus lateralis muscle architecture (muscle thickness, pennation angle, fascicle length) by B-mode ultrasound. CPET on cycle ergometer with breath-by-breath gas analysis; participants encouraged to volitional exhaustion. VO2PEAK defined as highest 20-second average near end of test; VO2AT determined by modified V-slope and ventilatory equivalents methods. CPET interpretation by two experienced blinded assessors. Sample size: A priori calculation (partial η² 0.15; effect size 0.42; power 0.80; alpha 0.05; correlation for repeated measures 0.7) indicated 40 patients (20 per group) to detect a 2 ml/kg/min VO2AT difference; maximum recruitment 48 allowing 20% attrition. Statistical analysis: Descriptive statistics as mean (SD), median [IQR], or n (%) as appropriate. Outcomes analysed using ANCOVA adjusting for baseline values. Normality assessed by histograms; relationships by scatter plots; equality of variance by variance tests. Correlations by Pearson’s or Spearman’s. Modified intention-to-treat on all randomised participants with both assessments; sensitivity analysis on prostate cancer patients completing ≥10 HIIT sessions. Stata 15.1 used. Timing: Median time from baseline to reassessment ~28–30 days; HIIT delivered within a 4-week window, compliant with UK 31-day target.

- Recruitment and adherence: 40 randomised; 34 completed both assessments. HIIT adherence (≥10 sessions) 84% (16/19). Median [IQR] HIIT sessions: 11 [10–12]. All participants during HIIT sessions achieved >85% predicted maximum heart rate. - Timing: Median [IQR] days baseline to reassessment: CON 28 [22–29, 31–33]; HIIT 30 [27–29, 31]. - Cardiorespiratory fitness: VO2AT improved with HIIT vs CON by mean difference (MD) 2.26 ml/kg/min (95% CI 1.25 to 3.26). VO2PEAK improved by MD 2.16 ml/kg/min (95% CI 0.24 to 4.08). CPET wattage at failure increased by MD 12.86 W (95% CI 5.52–20.19). In HIIT group, improvements in VO2PEAK (r = 0.02, p = 0.60) and VO2AT (r = 0.04, p = 0.43) were not correlated with baseline values. Sensitivity analysis in prostate cancer patients: VO2AT improved by 2.19 ml/kg/min (95% CI 1.06–3.32). - Cardiovascular health: Resting blood pressure reduced after HIIT: SBP −8.2 mmHg (95% CI −16.09 to −0.29); DBP −6.47 mmHg (95% CI −12.56 to −0.38). No change in CON. - Muscle architecture: In vastus lateralis, muscle thickness increased (MD 0.22 mm; 95% CI 0.02 to 0.41); pennation angle increased (MD 2.49 degrees; 95% CI 0.42 to 4.55). Fascicle length unchanged (MD −0.08 mm; 95% CI −0.87 to 0.71). - Body composition (DXA): No significant changes: total weight −0.25 kg (95% CI −1.07 to 0.57); total body fat % +0.13% (95% CI −0.64 to 0.90); total lean mass −230.9 g (95% CI −1156.10 to 694.16). - Safety and acceptability: No adverse safety events; two reports of mild, self-limiting leg pain/seat discomfort. Quality of life measures showed no significant change: WEMWBS −0.88 (95% CI −4.17 to 2.4); EQ-5D-5L VAS +3.65 (95% CI −1.97 to 9.28); EQ-5D-5L index −0.03 (95% CI −0.08 to 0.02). Patients reported HIIT as enjoyable and highly acceptable and would recommend it to others.

The study demonstrates that patients with urological cancers, predominantly prostate cancer, can achieve clinically meaningful improvements in cardiorespiratory fitness within the 31-day preoperative period using a low-volume, supervised HIIT protocol. Improvements in VO2AT and VO2PEAK met or exceeded the minimal clinically important difference previously associated with reduced postoperative complications in other surgical cohorts, addressing the primary research question. Significant reductions in resting blood pressure after just one month of HIIT indicate additional cardiovascular benefits beyond CRF, potentially exceeding the potency of traditional aerobic training within the same timeframe. The supervised, individualized, laboratory-based delivery ensured adherence and achievement of high-intensity thresholds, likely contributing to the efficacy observed, though it may limit pragmatic scalability. Despite no measurable short-term changes in quality of life metrics, patients perceived the program as acceptable and beneficial. Delivering effective prehabilitation within UK cancer pathway timelines enhances feasibility and generalisability, as most urological cancer patients receive treatment within 31 days of decision to treat.

A brief, supervised HIIT program delivered within 31 days before urological cancer surgery significantly improves CRF (VO2AT and VO2PEAK) and reduces resting blood pressure without adverse events, offering a feasible and clinically meaningful prehabilitation approach. Future larger randomised trials should evaluate the impact across diverse urological and other cancer types, effects on postoperative complications, socio-economic outcomes (e.g., return to work, healthcare utilisation), and long-term survival, as well as explore scalable delivery models beyond supervised laboratory settings.

- Delivery model: The supervised, laboratory-based HIIT protocol is resource-intensive (equipment and staffing), potentially limiting scalability and real-world implementation compared with home-based or unsupervised programs. - Blinding: Participants were not blinded to allocation, which may introduce performance or reporting bias, although outcome assessors were blinded. - Sample and generalisability: Single-centre study with a relatively small sample size and a cohort predominantly comprising prostate cancer patients, which may limit generalisability to other urological malignancies. - Duration: Short preoperative window limits assessment of sustained physiological adaptations, body composition changes, and quality of life effects. - Attrition/timing constraints: Not all randomised participants completed both assessments due to scheduling and perioperative timing constraints inherent to the 31-day pathway.