In Fitness Workout XL Game for Boys and Girls you start as a skinny geek who wants to work out and build solid muscles.
First you choose your gender and then your job is to maintain the routine and find everything you need to stay motivated.
Step by step you unlock new machines and you get better every time you step in to the gym. Feed yourself with quality food and definitely get some quality sleep.
Once you see your transformation, you get even better motivation to work harder. Good luck and have fun!