No, not your legs, your feet.
You’d be forgiven for assuming that going for a run or doing particular stretches would completely work out your entire lower body. The thing is, though, going for a run is fantastic for your legs, but your feet may not be reaping the full benefits. After all, a shoe essentially makes your foot function as a flat surface at a 90-degree angle, which means all the joints and ligaments of your toes and heel and whatnot aren’t really getting any dedicated attention. Having stronger, more flexible toes can make you a much better runner, as they’re what allow you to quickly pivot and maintain your balance.
If running’s your favorite thing, you can totally work out your toes with a run; you just gotta get creative with it. For example, if you know of a clean stretch of land like a beach, you can try running barefoot. Without cushioning from a shoe, your toes will need to do more work to compensate. If running barefoot isn’t an option, try wearing minimalist shoes with less padding and less-restrictive designs. Just enough to protect you from rocks and shells and whatnot, but also thin enough so that you can really feel everything with your toes.
There are also specialized toe-centric exercises you can try. For example, do you happen to have a jar of marbles or other small, smooth objects lying around? Dump them out on the floor and spend a few minutes picking them up and putting them down with nothing but your toes. Performing these kinds of precise movements will encourage you to flex and work your toes in unconventional ways. Do you have a hand towel? Pick it up with your toes and use them to pull the towel down toward your foot. It’s like a hand grip, but for your feet.
Remember, every muscle and joint in your body is a realm in itself, so give them all the attention they deserve to achieve true roundedness.