ok, so I am 21 years old and my resting heart rate ranges from 70-90 beats per minute, after being on the olyptical for 10 minutes on level one my heart rate shoots to about 160 and continues to climb I was finally told by an experienced work out lady my heart rate was too high when it reached 180 in less then 15 minutes..now I have been to the cariologist and she said my heart looked fine from the echo cardiogram even though my heart rate reached maximum heart rate (203) in 20 minutes of the tredmill ( anyone who has taken or seen th tredmill tests know they do not go fast at first) I was barely jogging BUT, when my follow up consultation came around I had a class to be at and because I forgot to call I can not get another appointment with her. I weigh about 157 lbs which is high for me I am also 5'7". This all started after I had my son a year ago when I gaines 65 lbs to pregnancy and lost 30 of them now I have 30 to go...I understand the weight is a contributing factor, I also had a very low platelet count and toxemia...any way My husband and I would like to have more children but I refuse until I believe I am healthy enough please help...