Low intensity shouldn't involve panting at all, because low intensity exercises are designed for people with specific health issues where anything above slight exercise is dangerous to them. [consider: significant osteoperosis, serious heart disease, etc] Stretching is low intensity exercise.
Also, an exercise you can only keep up for 20 minutes at a time is pretty high intensity.
Also, an exercise you can only keep up for 20 minutes at a time is pretty high intensity.