A new study led by the University of Oxford on over 90,000 participants shows that there is no upper threshold to the benefits of exercise in reducing the risk of cardiovascular disease – ‘every move counts towards better cardiovascular health.’
Cardiovascular disease is the leading cause of death globally, claiming around 17.9 million lives each year (World Health Organization). A new, large-cohort study involving NDPH researchers has accurately quantified the extent by which physical activity reduces cardiovascular disease risk. This found that physical activity is not only associated with lower risk of developing cardiovascular disease, but the greatest benefit is seen for those who are active at the highest level. The results were published today in PLOS Medicine.
The study was based on over 90,000 healthy participants in the UK Biobank, from across England, Wales, and Scotland. These were sent a wrist-worn accelerometer to measure their amount of moderate and vigorous activity, besides the total amount of physical activity, over a seven-day period in 2013 to 2015.
The participants were then followed up for a period lasting over five years. The researchers recorded the number of first hospital admissions or death caused by cardiovascular disease. These were obtained from the national Hospital Episode Statistics and the national death index.
Over the five-year follow up period, 3,617 of the participants were diagnosed with cardiovascular disease (3,305 nonfatal and 312 fatal). This included 2,220 men and 1,397 women.
There was a linear inverse association between the amount of measured moderate and vigorous physical activity, as well as total physical activity, and cardiovascular disease incidence, with no threshold of effect at low or high levels.
The protective effect of physical activity against cardiovascular disease was:
- 48%-57% for those in the top quarter of all physical activity
- 49%-59% for those in the top quarter of moderate-intensity activity
- 54%-63% for those in the top quarter of vigorous-intensity activity.
A subgroup analysis showed that these results were similar for men and women, although the benefits of vigorous exercise appeared to be particularly strong for women.
The strength of the association for the total amount of physical activity was similar to that for moderate and vigorous physical activity. The study investigators say that further research is needed on what combination of moderate and vigorous physical activity gives the most benefit. But the overall message is clear: more exercise at any level is better.
This protective effect is significantly higher than that reported by previous questionnaire-based studies. These estimated the protective effect of physical exercise against cardiovascular disease, for those who are more versus less active, to be about 20%-25% for total physical activity, 20%-25% for moderate-intensity physical activity, and 30%-35% for vigorous-intensity physical activity.
Associate Professor Aiden Doherty from NDPH and one of the lead authors of the study said: ‘This is the largest ever study of exquisite device-measured physical activity and cardiovascular disease. It shows that physical activity is probably even more important for preventing cardiovascular disease than we previously thought. Our findings lend further weight to the new WHO guidelines on physical activity which recommend at least 150 to 300 minutes of moderate to vigorous aerobic activity per week for all adults’.
Although those who exercised more were also more likely to not smoke, to have a healthy BMI and a moderate alcohol intake, the researchers adjusted for these factors and found that the inverse association was still strong. These results demonstrate, therefore, that exercise alone has a significant effect on cardiovascular disease risk.