PMID 35088469

Research
All papers

Short-term high-intensity interval training improves fitness before surgery: A randomized clinical trial

Woodfield JC, Clifford K, Wilson GA, Munro F, Baldi JC

Question

Can a short preoperative HIIT program improve VO2peak before major abdominal surgery, and what postoperative clinical signals are observed?

Summary

This single-center randomized trial tested whether a short, supervised HIIT program could improve fitness before major abdominal surgery. Patients aged 45-85 were assigned to standard care or about 14 HIIT cycling sessions over 4 weeks. The HIIT group improved VO2peak by about 2.7 mL/kg/min more than standard care and also improved peak work rate. Clinical outcomes such as complications and hospital stay numerically favored HIIT but were not statistically significant. The program was fairly intense and frequent, averaging 3.7 sessions per week and about 100 total minutes of intense exercise, with minimal adverse events under supervision.

Methodology

  • Adults aged 45-85 scheduled for major abdominal surgery.
  • 63 participants.
  • Stationary cycling.
  • Work intervals: Initially 1-minute high-intensity intervals; progression toward 2-minute intervals.
  • Recovery: Initially 1-minute active rest at >=60% HRmax; later 1-2 minutes lower-intensity cycling.
  • Intensity: Goal to reach 90% HRmax at least once per session and then in as many intervals as possible.
  • Approximately 30 minutes.
  • About 3.7 sessions per week on average.
  • 4 weeks / 14 prescribed sessions.
  • Single-center, two-arm, parallel, prospective randomized controlled trial.
  • VO2peak, Peak work rate, Anaerobic threshold, and Postoperative complications were tracked.

Outcomes

VO2peak

HIIT improved VO2peak meaningfully more than standard care.

HIIT +2.87 +/- 1.94 vs standard care +0.15 +/- 1.93 mL/kg/min; difference 2.73, 95% CI 1.53 to 3.93, p < 0.001.

Improved

Peak work rate

Peak work rate increased significantly in the exercise group compared with control.

p = 0.037 per-protocol; p = 0.05 ITT.

Improved

Clinical outcomes

Complications, length of stay, and SF-36 physical component numerically favored HIIT but were not statistically significant overall.

Complications per patient 0.64 vs 1.16, p = 0.072; mean LOS 5.5 vs 7.4 days adjusted p = 0.067; PCS overall adjusted p = 0.057.

Mixed

Adverse events

Two safety events were documented and resolved after stopping: arrhythmia during CPET and chest pain during HIIT.

Mixed

Insights

  • HIIT can improve VO2peak within 4 weeks when frequency and intensity are high.
  • A small amount of total hard work, about 100 minutes over the program, produced a meaningful VO2peak gain under supervision.
  • Short-term fitness gains do not automatically prove fewer complications; outcome-powered trials are needed.
  • High-risk users need screening because CPET and HIIT revealed cardiac symptoms/events.

Limitations

  • Underpowered for postoperative outcomes.
  • Patient blinding impossible.
  • Control-group disappointment and exercise contamination.
  • Selected motivated patients near hospital.
  • Supervised clinical context limits consumer generalization.

Safety

  • New arrhythmia diagnosed during initial CPET.
  • Chest pain during HIIT.
  • Both events resolved on stopping the intervention without sequelae.
  • Safety committee reviewed protocols and adverse events.