HOW MUCH EXERCISE DO WE NEED
Even half the recommended amount of exercise may reduce the risk of early death, diseases of the heart and blood vessels (cardiovascular disease), and cancer. Research suggests that an hour and a quarter per week (11 minutes per day) of moderate-intensity exercise can lower risk of these outcomes, compared with no exercise. The analysis supports the recent change to UK public health messaging that ‘some exercise is better than none.
Researchers analysed 196 research articles (involving more than 30 million adults in total) about the health benefits of exercise. They found reductions in the risk of early death, cardiovascular disease, and cancer with increasing amounts of exercise (up to 5 hours per week). They estimated that 1 in 10 early deaths could be prevented if everyone did at least an hour and a quarter of moderate-intensity exercise per week.
The researchers recommend that people do whatever exercise they can because even small amounts are linked with health benefits.
More information on exercise recommendations can be found on the NHS website.
how much exercise do we need to do?
Almost 18 million people around the world died of cardiovascular disease in 2019; it is the leading cause of death. Cancer caused 9.5 million deaths worldwide in 2017.
Regular exercise is known to reduce the risk of early death, cardiovascular disease, and some cancers. The NHS therefore recommends at least 2.5 hours of moderate-intensity exercise per week. This is exercise that increases your heart rate and makes you feel warmer. It could be brisk walking, cycling, or dancing, for example.
But exactly how much exercise is needed to achieve health benefits is not known. This review explored the links between different amounts of exercise and the likelihood of early death, cardiovascular disease, and some cancers.
What’s new?
The review was based on 196 research articles, which included data from 30 million adults without pre-existing conditions. The studies focused on exercise in people’s leisure time (rather than physical activity at work). They measured the impact of exercise on a range of outcomes including: early death, cardiovascular disease, stroke and heart failure, as well as cancers of the heart, lung, liver and breast, among others. All studies included 10,000 people or more, and lasted for at least 3 years.
On average, people were followed up for 10 years. Most (2 in 3) carried out up to 2.5 hours of moderate-intensity exercise per week.
In general, more exercise was associated with lower risks of all outcomes. The study found that:
An hour and a quarter of moderate-intensity exercise per week (half the recommended amount) reduces the risk of an early death, cardiovascular disease, and cancer, compared with no exercise
increased amounts of exercise (up to 2.5 hours per week) further reduced the risk of these outcomes
more than 2.5 hours’ exercise per week gave only small additional gains; there was little further benefit from more than 5 hours per week.
The analysis suggests that 1 in 10 (10%) early deaths could be prevented if everyone did an hour and a quarter of moderate-intensity exercise per week. If everyone did 2.5 hours, 4 in 25 (16%) of these deaths could be prevented.
Why is this important? Some exercise is better than none
Even small amounts of exercise protected against an early death, cardiovascular disease, and cancer. This finding suggests that every little bit of exercise, up to 5 hours per week, is linked with these health benefits. More than 5 hours of exercise per week was linked to only slightly greater protection against disease.
This is one of the largest analyses of its kind. All studies included in this review relied on people self-reporting how much exercise they did (rather than being monitored via a smart watch, for example) so some data may not be accurate. However, researchers standardised data from studies that had measured exercise on different scales. This meant that the review was more comprehensive than many and included studies that are difficult to bring together.
The estimate of the number of deaths that could be prevented by exercise assumes that exercise protects against early death (which is not certain but highly probable), and that study participants were representative of the wider population.
What’s next?
The researchers say their review supports the current UK recommendation of 2.5 hours of moderate-intensity exercise per week. However, health benefits can be gained from just an hour and a quarter per week. The study therefore supports the recent change in public health messaging to ‘some exercise is better than none.’
Policymakers could consider these results when recommending a minimum amount of exercise for the public.
You may be interested to read
This Alerts is based on: Garcia L, and others. Non-occupational physical activity and risk of cardiovascular disease, cancer and mortality outcomes: a dose–response meta-analysis of large prospective studies. British Journal of Sports Medicine 2023; 57: 1 – 15.
A Collection on what local authorities can do to reduce obesity.
Information from the British Heart Foundation on the benefits of exercise.
Information from Cancer Research UK about how obesity is linked with cancer.
Funding: This study was conducted by Centre for Diet and Activity Research, which receives funding from the NIHR. The study also received funding from the Medical Research Council and the European Research Council.
Conflicts of Interest: None declared.
Disclaimer: NIHR Alerts are not a substitute for professional medical advice. They provide information about research which is funded or supported by the NIHR. Please note that views expressed in NIHR Alerts are those of the author(s) and reviewer(s) at the time of publication. They do not necessarily reflect the views of the NHS, the NIHR or the DepFundingartment of Health and Social Care.