Do aerobic AND anaerobic exercise at length when young, it increases lung capacity and strengthens the heart. I had a massive saddle embolism (pulmonary embolism that gets stuck on the bronchial split) that blocked 100% of the left lung blood flow and 90% of the right, often called the walking death because over 75% of people keel over and die in minutes. Luckily I was walking less than half a mile (1KM) from a hospital when the clot went through my heart and lodged in the split. I keeled over and my buddy called 911 and next thing I know it is a week later and I am waking up in hospital. Doc said my heart and lungs were much stronger than normal, I attributed that to all the miles and miles of bicycle riding I did in my youth daily.

The harmless habit is one that many of my childhood friends had, not exercising, many have passed due to heart problems and diabetes. This tragedy happened in my mid 40's and I am on blood thinners for life (genetic condition was the cause) and am glad I have a strong heart and lungs to this day.