sleepygeek - Try body-weight exercises. They are great for toning and building muscle (though women tone more than build, rather than men who build rather than tone).
I'm sure you can pull it off well.
Free - Soul Eater (Otakon 2013, Completed)
Goku - Dragon Ball Z (Otakon 2014, Completed)
Teen Goku - Dragon Ball Z (Otakon 2015, completed)
Powerline!Max - A Goofy Movie (Otakon 2015, completed)
Cafe!(neko)Kaneki Ken - Tokyo Ghoul (Otakon 2015, completed)
My Facebook cosplay group - Southern Maryland Cosplay
(Anyone can join)
Author of the "Getting Fit for Cosplay" Katsucon panel.