University of Otago Medical School researcher and lead investigator Dr Kari Clifford is urging policy-makers to take notice of the study, which could have a substantial influence on the New Zealand health system.
As part of the research, 12 studies were reviewed and analysed, including 832 patients who had undertaken pre-operative high-intensity interval training.
Such training involved repeated aerobic high-intensity intervals at 80% of the maximum heart rate, followed by active recovery, she said.
The study included all types of major surgeries — those expected to last more than two hours or with an anticipated blood loss of greater than 500ml — and included liver, lung, colorectal, urologic and mixed major abdominal surgeries.
The average age of participants in the intervention group was 66 and 67 in the control group, she said.
"We have found that high intensity interval training [HIIT] is safe and effective for surgical patients.
"A HIIT programme can meaningfully improve a patient’s fitness within four to six weeks, and this reduces post-operative complications and length of stay."
The most significant result was the change in cardiorespiratory fitness — a measure of how well the body took in oxygen and delivered it to the muscles and organs during prolonged periods of exercise, Dr Clifford said.
"The pooled results suggest that HIIT increases cardiorespiratory fitness by 2.39ml/min/kg.
"This is not only significantly different than standard surgical care, but is also clinically relevant.
"We know that this level of increase is associated with a lower risk of adverse post-operative outcomes."
Post-operative complications occur in about 30% of patients, or up to 50% for frail patients.
In the study, those who undertook HIIT before surgery showed a consistent reduction in post-surgery complications, such as cardiac complications, pneumonia and post-operative bowel issues, Dr Clifford said.
"All of these findings suggest that a period — even as brief as four weeks — of pre-surgery high intensity interval training may substantially improve patient outcomes and bring with it robust benefits across patient populations."
The next step was to work out how to implement HIIT programmes, she said.
