I had an issue with my heart rate, and being winded when I started cycling 3 weeks ago. After a week of no improvement, went to the Dr. and found out it was due to my blood pressure meds. Dr switched me to a new med, it seems to have improved significantly. Dr. also reminded me as I loose weight to check and make sure my BP isn't falling to low. The hope is, as I loose it, the BP will go down.