Hi, recently I stretched a ligament in my elbow and can not work upper body for four weeks (it's killing me). I've just been working core, flexibility and running, but someone told me that running too much could make me lost my muscle mass.
What should I do during this period while I'm injured? Should I take this time as a bulking period, a cutting period, or what? Summer training starts June 11, and I really don't want to be behind. I'm 15 and male, too, if that helps.
Thanks.