Both mothering and running, you can do on your own and in the company of others.
As a mom I love to seek out other moms. To hear how they are doing, and to know that I'm not crazy when I feel like I'm going crazy.
Running however, I prefer to do all by my self. Because running helps me find myself. And I know if I run with someone else I'll start worrying if I'm going too slow, and holding her back. Or I'll start talking, and talking and get all sidetracked and lost.
Admittedly there are times when I wish I hadn't found myself, and I feel like running far, far away from me, but hey, that's when I run the fastest!
As a mom it's important to go out and look for yourself. Because your Self is a colleague you'll never outrun.
No matter how fast you run.