This is a plain English summary of an original research article. The views expressed are those of the author(s) and reviewer(s) at the time of publication.
High-intensity interval training (HIIT) significantly improved men’s fitness in the short timeframe before cancer surgery. A small study found that HIIT improved the heart and lung (cardiorespiratory) function of men with urological cancers such as of the prostate, bladder or kidney.
The authors hope their findings will lead to the development of effective exercise regimes for men with these cancers who are waiting for surgery. Patients with other types of cancer may also benefit from similar training.
What’s the issue?
Cancers of the prostate, kidney and bladder are common in the UK, with over 69,000 new diagnoses each year. Surgery carries a high risk of complications. Many patients struggle to get back to their former levels of physical ability, with a knock-on effect on their quality of life.
Clinicians are aware of the importance of optimising patients’ overall health before surgery. This multi-pronged approach is known as prehabilitation. Previous work has suggested that improving cardiorespiratory fitness before surgery reduces the risk of complications, increases quality of life after surgery, and improves long-term survival rates.
In the UK, the National Cancer Action Team states that initial treatment should take place within 31 days of the decision to treat. This leaves only a small window in which prehabilitation can take place.
Previous studies have found that HIIT can improve the health of patients with certain cancer types over short time periods. However, within urology, most prehabilitation studies have focussed on reducing specific complications, such as urinary incontinence, rather than general fitness.
This study aimed to assess whether HIIT could improve cardiorespiratory fitness within four weeks in patients with urological cancers awaiting surgery. The authors examined the effect of HIIT on blood pressure, body composition, and muscle structure. Once the exercise regime was completed, patients were asked whether they enjoyed taking part.
What’s new?
This randomised controlled trial included 34 cancer patients over the age of 65 who were scheduled for major urological surgery. Most patients completed between 10 and 12 HIIT sessions on an exercise bicycle in a university laboratory. Patients completed five bursts of exercise, each of one minute. They all achieved more than 85% of their maximum predicted heart rate during the sessions. They rated the exercise protocol as highly acceptable and enjoyable.
After 31 days, the authors identified a meaningful improvement in cardiorespiratory fitness for the patients taking part in HIIT, versus those undergoing standard care in the control group. The study reports improvements in:
- the highest intensity exercise that can be sustained without lactate building up in the blood and causing muscle fatigue and pain (the anaerobic threshold)
- the peak volume of oxygen utilisation, a measure of aerobic fitness
The authors also found:
- a reduction in blood pressure (systolic blood pressure: -8.2 mmHg; diastolic blood pressure: -6.47 mmHg)
- an increase in the fibre quality and thickness of the thigh muscle, vastus lateralis
Why is this important?
Within a month, this HIIT regime improved cardiorespiratory fitness, cardiovascular health, and muscle condition. This makes the protocol a feasible prehabilitation tool in the 31-day target window between cancer diagnosis and treatment.
Further research is required to assess patient outcomes after surgery. But the authors suggest that the reported improvements in physical fitness could help reduce medical problems and deaths related to surgery and speed up patients’ subsequent recovery.
Comparing the results of this study with other prehabilitation exercise research suggests that HIIT could deliver greater improvements in fitness than other approaches such as walking and traditional aerobic exercise.
The HIIT protocol followed here – carried out in a laboratory setting with a doctor present – is unlikely to be delivered in a real-world setting. The authors note that it may be difficult to ensure exercise intensity and compliance in unsupervised training.
What’s next?
The authors hope that larger, randomised trials will provide firmer links between HIIT and improved outcomes after cancer surgery.
Further research is also required to:
- examine the responses of other patient groups – including different age groups, patients who also have other conditions (comorbidities), and patients with other cancer types
- establish optimal exercise methods
- work out how best to roll out HIIT to large numbers of patients
- take into account dietary intake and habitual activity levels
The study was part of a larger project, which is analysing muscle biopsy samples. This ongoing research aims to deepen understanding of the biological mechanisms behind the improvements reported here.
You may be interested to read
The full paper: Blackwell JEM, and others. High-intensity interval training produces a significant improvement in fitness in less than 31 days before surgery for urological cancer: a randomised control trial. Prostate Cancer and Prostatic Diseases. 2020 (online ahead of print)
Principles and guidance for prehabilitation by Macmillan Cancer Support
Prehabilitation evidence and insight review by Macmillan Cancer Support
Funding: This research was supported by the NIHR Biomedical Research Centre in Nottingham.
Conflicts of Interest: The authors have declared that no competing interests exist.
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