Artist: https://www.deviantart.com/tf-ai/art/Rainbow-Dash-Muscle-Adoptable-1126166840

One day, Dash decided she wanted to get into the Wonderbolts. But Equestria's strongest and most athletic fliers only take the best. And while the cocky blue pony didn't think she had any peers, maybe a little chemical assistance might ensure she really was the best.

The fit pone started her first cycle and began training, and 12 weeks later showed up to the Wonderbolts tryouts bigger, stronger, and faster than ever. She blew the doors off the competition, passing every test with flying colors EXCEPT the drug test. Turns out that the rules don't allow pony-enhancing drugs, and Rainbow Dash was politely asked to leave.

Only now she has a new goal. Turns out there is a burgeoning bodybuilding circuit in Equestria, and they don't test quite as stringently as the Wonderbolts do. That and Dash finds out that she REALLY likes being on the sauce, being so big and now she just wants to get bigger. So with a chemically boosted ego, Dash sets about training for her first bodybuilding competition. Good thing she has her supportive boyfriend to help her train (and deal with all the side effects~)

Tags: pony, rainbow, dash, anthro, mlp, equestria, fim.