Last summer, my father decided, at age 70, to start running again to help lose weight. However, he had noticed a little shortness of breath while using his exercise bike, and decided to have that checked out first. And it’s a good thing he did. My father, it turns out, was a heart attack waiting to happen.
He had several blocked arteries, and had to have several grafts put in, over a number of weeks. I still feel weak when I think about it. If he had decided suddenly to go out for a jog, he could have ended up in real trouble. The study shows that sudden short bursts of intensive exercise are harmful to heart patients, because the exercise increases blood clotting.
Researchers are still not entirely sure why exercise stimulates blood clotting, but it seems to, particularly in heart patients compared to healthy controls. Consistent, regular exercise is still the best bet for everyone, especially heart patients. But it is important not to charge into a sudden bout of exercise without making sure you are in the clear, first.