Hi, I am a 24 year old female and I run 25-30 miles per week. I have a normal blood pressure (one teens over seventies usually) and a normal resting heart rate at around 58 bpm. I have no history of cardiac illness, and neither does anyone in my family. Recently, I had an annual physical at my university’s clinic, and I asked to have an EKG ran (no chest pain, just curious what it said). It stated that I was in “sinus bradycardia” but that, with the msec, “-Left axis for age- possible anterior fascicular block.”

My friend (a nurse practitioner) is wondering if it is artifact, because some of the leads don’t show the block. I plan to have the EKG repeated, but my question is this: is it safe to run/walk/jog in between EKGs?