Couple things here. "Muscle Hamster" is a pretty lame nickname. Hamsters are cute, puffy little pets that, no matter how much time they put in at the gym, will never truly be seen as intimidating. So yeah, I see where Doug Martin is coming from. Unfortunately for him, the more upset you get about a nickname, the more likely it becomes that people are going to call you that nickname. Doug Martin trying feverishly to erase whatever connection he has to a rodent that runs on a wheel only makes it more fun to refer to him as such. You refuse to let something get to you, and people will stop trying to use it to get to you. Pretty sure when my sister stopped crying after every time I made an art school joke, I stopped making art school jokes. Wipe your tears Dougie and maybe people won't find it as humorous to use a nickname that you loathe.
More importantly, you can't make up your own nickname. That's a fact. That's something you learn in grade school. "Call me (insert over glorified nickname here)" only works for like a week when you are 6 years old and you're talking to your parents, and even they hate you for it. Are you a little kid Doug? If you are it would make a ton of sense, because your choice of a replacement name is absolutely elementary. At least with "Muscle Hamster" he has the excuse that someone else created it. It's wayyyyy worse to willingly declare yourself "Dougernaut". He sounds like a lead character on a Cartoon Network show that didn't even make it past the pilot episode. It's one thing for a fan, or a coach, or a teammate to frivolously throw out "Muscle Hamster", but you just know that Doug Martin sat down with a pad and a pen for hours and thought he was a genius when he finally came up with "Dougernaut". As if that's not pathetic enough, I think, all things considered, I actual like "Muscle Hamster" better than "Dougernaut", regardless of who came up with them. Doug Martin is in the middle of an identity crisis, and he's doing a terrible job of altering his ego.