Re: Running a marathon stop menstruation?
I did a triathlon back in August, and trained very hard for it. I missed my period for 3 months straight after my race. So yeah, it can happen. However, I'm also 43, so it could just be perimenopause, too. How old is your GF? If she's young, then it's most likely the stress from training/racing that is responsible for the delay in her period.