Most of us likely never have to worry about getting too much exercise. But should we ever approach the level of extreme athletic training, the research here indicates we are probably still safe from coronary incidents, barring other factors or causes.
Physical activity for health and wellness does not necessarily mean grunting and slinging weights in a smelly gym. It means we simply have to be more active than our usual lifestyle. The goal is moderate activity (raise our heart rate & sweat a bit) about 150 minutes per week. That is about 30 minutes per day, 5 days per week. And it can be done in three 10-minutes bouts per day. Make exercise a habit.