Mary decided that she would go to the local gym to work out. She did gain this much muscle mass, after all, and it would be a waste not to use it.
She took a few moments to grab her things, and when packing her gym bag, she picked up her wallet. Accidentally fumbling it, the wallet fell on the floor open, revealing her photo ID. Noticing something different about it, Mary picked it up. She gasped in shock. Her ID had completely changed. According to the ID, her name was Maria, she was a few inches shorter (5’7 to 5'4), and she was now 24 years old instead of 27, not to mention her new photo. Apparently, when she looked for further information around her house, she and her family had immigrated from Russia as a teenager to become a gymnast and bodybuilder, and had become quite successful, as seen in her many awards that she found in her room.
Taken aback at the new information, Mary - or Maria now - decided that it was probably best to still go to the gym, as it would likely provide a good outlet for processing this new information while still sticking to her original plan.
Maria got on with her exercise, marveling at how much easier everything felt than before her change. She could curl 150 lbs, squat 250 lbs, and even deadlift 400 lbs. And that only took a little bit of effort! She could easily max out some of the machines and do several reps with them. She was also extremely flexible, doing some stretches that the old her could only hope to do. She was euphoric in this new body, glad that she decided to take the vial.
After a long and thorough workout, Maria returned home. Sitting at her table for a rest, she noticed the box of vials still there. Curious, she rummaged around in it and found the Russian vial again, and was shocked to find it completely full again. She wondered what effect the vial would have on her now, considering that she had already downed it earlier. How much more Russian could she get, anyway? She searched through the box some more, finding vials labeled things like ‘fox’, ‘weight’, ‘muscles’ - wait, muscles? Maria paused and picked up the vial. If she increased her muscles, she would be even stronger, and have even more of this euphoric feeling.
Smiling with delight, Maria dug through the box some more, finding other vials that caught her attention, such as ‘breasts’, ‘height’, etc. She rubbed her hands together in excitement, wondering what to experiment with first.