OMG! So funny story time!!!
So, my advisor's friend in college did those experiments, and she just started a new one at the beginning of the term. She wasn't supposed to talk about it, so everyone was like "cool" and they kind of ignored it. So, basically, after like 6 weeks or something of the experiment, one of her biceps was HUGE and everyone flipped. Turns out, they basically sat in a room and did arm curls or something for an hour every day on just one arm

She wasn't allowed to work out her other arm, and to this day, her arms are STILL uneven...!!!