This is a plain English summary of an original research article
Aerobic exercise and resistance sessions that include supervision help people living with cancer to meet guideline physical activity levels. Common behaviour change techniques that were shown to increase physical activity are goal setting, graded tasks (e.g. increasing exercise duration or intensity over time), and instruction on how to perform particular exercises.
This review update looked at the most effective ways to increase and sustain physical activity for 1,372 sedentary adults living with and beyond cancer. Most trials used exercise machines in a gym.
The findings suggest exercise was generally safe in this group of but that the quality of evidence overall was low. The majority of studies looked at women with breast cancer, so findings may not be so readily applicable to other cancers with a different range of symptoms.
Why was this study needed?
People living with and beyond cancer can experience a range of health problems, including fatigue and poor mental health. Being regularly active can bring a range of health benefits including improved quality of life and physical function, and may also reduce the risk of cancer recurrence.
It has been estimated that less than 30% of people living with cancer meet the recommended physical activity levels. Because most cancer survivors are not regularly physically active, there is a need to understand how best to promote and sustain physical activity for these people.
This update to a 2013 Cochrane review aimed to assess which interventions are best at promoting regular exercise in adults living with and beyond cancer.
What did this study do?
The systematic review included 23 randomised controlled trials involving 1,372 sedentary adults with or recovering from cancer. The trials compared an exercise intervention with usual care or a waiting list control. Fourteen studies looked at aerobic exercise, mostly using exercise machines, such as treadmills — nine combined aerobic exercise with resistance training such as weights. Participants exercised on average two to three times per week for 12 weeks, and the majority of sessions were supervised. The exercise tolerance was assessed through the 6-minute walk test or measures like oxygen levels, heart rate or breathlessness.
Most studies were in women with breast cancer while a handful were in adults with prostate, colorectal and lung cancer. Two studies were UK-based.
Though Cochrane reviews are carried out to a high standard, the individual trials were small and at high risk of bias. Many were missing details on the number of people who continued with their exercise programmes, particularly beyond six months.
What did it find?
- Eight trials reported intervention adherence of 75% or greater to an exercise prescription that met current physical activity guidelines and these trials all included a component of supervision (the 2013 review lacked trials that met current guidelines). Six trials reported intervention adherence of 75% or greater to an exercise prescription (aerobic exercise goal) that was less than the current physical activity guideline levels.
- The most frequent behaviour change techniques included in all of these trials were programme goal setting, setting graded tasks, and instruction on how to perform the behaviour.
- Exercise interventions resulted in moderate improvements in aerobic exercise tolerance at eight to 12 weeks compared with usual care (standardised mean difference [SMD] 0.54, 95% confidence interval [CI] 0.37 to 0.70; 604 participants, 10 trials, of low quality).
- At six months, aerobic exercise tolerance also improved moderately compared with usual care (SMD 0.56, 95% CI 0.39 to 0.72; 591 participants, 7 trials, of low quality).
- A very small number of serious adverse effects were reported amongst the trials, and it was not clear if these adverse effects were caused by inclusion in the intervention group.
What does current guidance say on this issue?
The 2011 UK Physical Activity Guidelines for adults recommend at least 150 minutes of moderate intensity activity in bouts of 10 minutes or more per week, or 75 minutes of vigorous activity per week. Adults should also undertake strength training activity on at least two days a week and minimise sedentary behaviours.
According to Cancer Research UK, in general, the same level of activity is recommended for people with cancer as for the general population as long as it takes into account the person’s overall fitness, diagnosis and other factors that could affect safety.
What are the implications?
Evidence from this review suggests supervised exercise interventions can help people living with and beyond cancer meet recommended activity levels for up to six months.
Overall, including 10 new trials in this update has added some clarity on the behaviour change techniques that are useful in encouraging physical activity in this group.
There is now a clearer case for including these techniques in healthcare professionals’ training, including physiotherapists, who advise patients on physical activity.
However, because most trials were small and the research lacked detail on adherence, there remains uncertainty on how to effectively encourage sustained changes in physical activity beyond six months.
Citation and Funding
Cochrane UK and the Cochrane Gynaecological, Neuro-oncology and Orphan Cancer Group are supported by NIHR infrastructure funding.
Department of Health. UK physical activity guidelines. London: Department of Health; 2011.
Mishra S, Scherer RW, Geigle PM et al. Exercise interventions on health related quality of life for cancer survivors. Cochrane Database of Systematic Rev. 2012;(8):CD007566.
Rock CL, Doyle C, Demark‐Wahnefried W et al. Nutrition and physical activity guidelines for cancer survivors. CA: A Cancer Journal for Clinicians. 2012;62(4):242-74.
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