Well, for one thing you don't know for certain that the wives/partners of the men you see at your running club are not doing exercise/training of their own, but just a different times/places/different types of exercise. They may go to the gym or run on the evenings their partner is not out training with the club, or train in the mornings/lunchtime in order to balance out their partner's evening commitment. I see a lot of women at the swimming pool where I train in the mornings, for instance. So it's not safe to assume that the wives are not partaking of exercise or training.
In terms of women's participation in sports more generally and the competing demands of family life, work etc. with sports, well that is a much wider issue. There have been all sorts of studies into why women's participation drops off so exponentially from the late teenage years onwards, and campaigns such as 'This Girl Can' are designed to try address this. But anyone who participates in a sport, even if they don't have a family or partner, will have to make choices about how to spend their time, and possibly 'sacrifice' an aspect of life at times in order to pursue that sport. For both men and women who have families, I imagine it is about compromise and a fair division of labour as much as possible so that both parties can pursue their interests as much as possible, be it sport, or other kinds of activity.