For years I had been fighting against hypertension (high blood pressure). My lifestyle didn't help. In the past 4 months, I have been riding. I was progressing nicely, when suddenly I started seriously bonking on my short (15 mile) lunchtime rides. My fellow newbies started passing me and dropping me. I also noticed a light headedness. My blood pressure was dropping. I quit the meds as an experiment (I DON'T recommend this w/o doctor supervision) and found that I was yet again able to drop some of my other fellow newbies.

I have since went to my doctor and have the blessing to continue without meds and monitor my BP.