How do you feel about photographing yourself in the nude?
No, I'm not suggesting the typical selfie (selfy?).
I am suggesting that you take the project on with all the deliberation you would photographing a model. Light, accessorize, pose, and compose for your optimal effects for your available "model." I think it will present some significant and relevant challenge to you creatively and technically.
Immediately, I am also suggesting if you do want to progress from portrait to figure studies, there are several stages of development in the art. Showing the progression of your skills in your portfolio may help you communicate your ultimate interest to future models of your choosing. It will also sharpen your sensitivity to distinctions between what appears attractive, weird human contortion, or some pornographic crap.
Look around at what's already available and very similar.
Sports photography can be challenging from a figure-study point of view. Boxing, gymnastics, track & field, etc. also are great. Expressive dance, ballet, and even ballroom dancing can make exciting figure studies.
Sometimes an otherwise uneventful portrait session will present opportunities for a discrete (the model's identity obscured) reveal.