I am a 66 year old master swimmer, female in good shape with slight asthma problems, easily controlled, use my inhaler infrequently. What happens to your body, heart, lungs and BP when you sprint as fast as you can? I know your heart rate increases, does your BP go up? What signs would I have that I have pushed myself too hard? I can do repeats for awhile but I can t keep up with the kids. (40 year olds)