New study: The more you do, the better your health

Oxford study shows that physical activity is twice as important than previously thought in the prevention of cardiovascular disease. 

Reuben Fellow Aiden Doherty is one of the lead researchers involved in the first large-scale study of its kind that accurately measures physical activity against cardiovascular disease (CVD) outcomes. 

Cardiovascular disease is the leading cause of death globally, claiming around 17.9 million lives each year (World Health Organisation). A new, large-cohort study involving researchers from Oxford University's Nuffield Department of Population Health has accurately quantified the extent by which higher physical activity is associated with lower CVD risk. The study 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 study (published this week in PLOS Medicine) 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 2013-2015. 

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). People in every increasing quartile of physical activity, for moderate-intensity activity, vigorous-intensity activity and total physical activity, were less likely to have cardiovascular disease. 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. 

This protective effect is significantly higher than that reported by previous questionnaire-based studies. In the past, the protective effect reported by questionnaire-based studies is about 25% for total physical activity – whereas using more accurate device-based measures, the protective effect is found to be over 50%. 

Reuben College Official Fellow Aiden Doherty, who is an Associate Professor in the Nuffield Department of Population Health 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. 

Watch Aiden explain the approach to their research and findings from their study in the video below: