It all seems to do with the way different types of activity affect our heart rhythm. An abnormal rhythm suggests a problem with the walls of our arteries and this, in turn, can lead to cardiovascular disease.
It's a new way of looking at heart disease, say scientists at Inserm in France, who wanted to assess how different activities affect heart rhythms. Although we've been told that all forms of exercise are good for the heart, the Inserm research team wasn't so sure, and tracked the heart health and activity of 10,000 volunteers for 10 years to find out.
The participants completed regular questionnaires where they logged their activity in sport, in their leisure time, such as gardening, and at work, and the health of their arteries was also checked.
Although general movement at work is good for the heart, lifting heavy loads isn't, they discovered. Intense sporting activity is the best for maintaining a healthy heart.