I would like to train for a half. The most I've done so far is a 10K. I have never been fast at all. I am very slow. But since the meds, my endurance is all but gone. Down to doing intervals at 2 minutes running, 1 walking. I am so fatigued, and my muscles feel so heavy. I have researched the medication and know it has to do with the fact that my muscles are not being oxygenated the way they need to be. Is there anyone out there taking lopressor or a similar med who can give me some tips on how to get past this? I refuse to give up!!! Thanks!!!