Well, most people who think they know all there is to know about the vaginal muscle will tell you, “No, of course, not that is silly, the vagina is it’s own set of muscles, and running won’t help.” But, you see, that is simply not true at all. You can say, well, running, just works out your legs, but, wait, then your arms move, and your neck, your head, hands, and you realize that pretty much every part of your body is getting a work out when you run.
There are muscles that run along the back of your buttock that support the pelvic floor and other supporting muscles that affect vaginal tightness. There are also muscles that are in the interior thigh that feed into the pelvis and support your vagina. And, then there are of course, abdomen muscles. All of these muscles play a role in the tautness of pelvic floor and help balance out the tightness that kegels can create when nothing else is done.
So, the answer is that, yes, running does tighten your vagina.