My reply might inspire your own pursuits as a model:
You can pursue print modeling and fitness modeling at the same time, you may need different comp cards though when pitching print modeling agencies. Keep in mind fitness modeling can fall into the area of parts modeling as well. Some print modeling agencies have "parts modeling" divisions, some don't. I think what will set you a part is your range to use your personality, friendly smile, relatable appeal that fits print modeling and also have assets that could be great for a product ad, editorial, or commercial that involves fitness/the body, legs, etc.
You could create a comp card that has a pretty beauty shot, smiling headshot on the front, or involves personality, and also include on the card shots that involve fitness/parts as well. Or make two different cards. One for print modeling showing more personality shots and beauty and one that has a more body/fitness appeal.
The photos you create will be important, and you want to keep them looking as commercial print friendly and as marketable as possible. When I say marketable I mean, photos that show you "can model naturally." There is a point to the shot. It looks like it "has an editorial or ad" vibe. So if it is a shot for fitness then study ads and editorials you see in fitness and health magazines, if it is a basic commercial print modeling photo that make sure you are showing your personality, friendly approachable persona.
What will set you apart is that you bring not just your personality, great skin, etc, but you bring a tone body that can be used for editorials and product ads and that is a great asset when you are a shorter girl. So you might not have the height, but look at all you can bring to the agency and their clients, all you CAN do.
Here are some samples of shots that might inspire you among beauty, health and fitness.
Fitness modeling isn't limited to only being buff or tone, it also involves health and beauty, you'll see in magazines like Self, there might be a close up a stomach, a back, legs, or a certain part, so make sure you study ads for lifestyle products and editorials about health and the body as well before shooting.
I hope this inspires you.