Cardiovascular disease is the leading cause of death globally, claiming around 17.9 million lives each year. Until now, it has been difficult to quantify the protective effect of physical activity, since previous studies have typically measured this using questionnaires. These methods are crude, subject to poor recall and cannot accurately record all activity that takes place throughout the day. This has made it difficult to assess whether increasing physical activity always gives an additional benefit in reducing the risk of cardiovascular disease, or if there is an upper limit on improvements to cardiovascular health from exercise.
A new, large-cohort study led by the University of Oxford has resolved this by using accelerometers (wrist-worn devices) to accurately record the activity of over 90,000 participants followed over five years. 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.