Keeping your feet healthy and strong is essential to being fit. Most athleticism stems from proprioception, or the sense of position in space, and this all comes from the feet — which have tens of thousands of nerves and more than a quarter of the bones in our body. "If you aren't doing exercises that are tapping into proprioception, you aren't engaging the foot," says sports therapist Taylor Hatcher. This means more than just foot strength — you need to roll, stretch, and engage your feet in a variety of ways. Here's where to start.