A common term used to describe a bodybuilder or other similar athletic enthusiast, analogous to "meathead" and similar terminology, most often used on Internet forums and communities.
In this usage, bro can often be combined with other words to create more descriptive phrases.
SuperMass4Lyfe is a good bro, he's got like 10,000 posts bro
u can use high reps to tone ur guns n bring out the cuts - Example of bro-science
ur a fagot, u cant argue w BroMasterChill hes a mod -
Example of bro-telligence