You're being sarcastic maybe? I would interpret it as really selfish if my partner put his personal fitness as a priority above our family functioning.
That said, I wouldn't enter a partnership with someone who did not respect my need for an hour or so of exercise 3-5 days a week and of course I would make the same effort to provide them that time as well, if they wanted it. In fact, I would argue that a persons physical fitness(to a certain level, of course) is crucial to a partnership and a healthy family. Full disclosure: my wife and I don't have kids- but these are my values and I'm proud enough of them to hope to bestow them on my kids if we ever have them.
If you're taking care of others to the exclusion of yourself, you're going to end up in a downward spiral of resentment. Nothing good will come of that.