If you like Fitness Models or Muscle Girls, you will have a hard time trying to find one in real life. One of the only places to find these type of girls in real life are usually big Gyms. But muscles girls don't like to get laid in Gym, they just want to work out hard to keep their perfect bodies athletic and muscular.
One good way to meet fitness girls are dating sites or webcam sites. A very good webcam site to find cute girls is Omegle Girls where you can interact in real time with girls in webcam. There are a lot of athletic girls and sport girls available. You can also make a lot of friends and meet with girls from all over the world.