I have lifted weights pretty much all my life. At my age, I have to lift "heavy" every so often or I back track in strength. For example, I bounce around between 275# and 315# in bench press (I am not Marlon Torres). Sometimes, I go up to over 350# to shock the muscles. The concept is called "Neuro Muscular Overload". But, I warm up properly and use good form. Thus, no injuries.
I like to use a bow heavier than I would normally shoot to either build strength or keep the strength I already have. If I shoot the bow too much, I get a little sore. However, afterwords my other bows seem light.
If may suggest, warm up with your regular bow, then shoot a bit with the heavier bow, and then go back down. That should keep you strong and un-injured.