I read this WSJ Endurance Widow, and noticed there was no real solution presented for how to not have marital strife as a result of significant increase of exercise on the part of one partner.
Here is my suggestion, and it is going to seem silly and stupid. Communicate. Talk about it. The first thing I did was copy this article and send it to my wife. I am aware that she gets frustrated when I am gone in the morning, or when I am gone in the evenings, or for 4 or 5 hours on the weekend days, or when I take a trip without her. She gets frustrated when I suggest races that I could do during our vacation, or even better yet, suggest scheduling our vacation around a certain race! She looks at me like I am insane when I suggest that I want to do a full Ironman distance race next year, or when I watch 2 hours of Ironman coverage on TV. The important thing is that I talk to her about it, and I know when I am going over that invisible line - because she talks back to me! "What do you think about going to Puerto Rico for vacation?" I say. She says, "Puerto Rico? Why there?" I reply and tell her, "Well, there is this race there, and I might get to meet Lance Armstrong!" The next part is the important part... It will either be met with a "Are you INSANE?", with a "Is there a better race, or one that is in ..." or "I guess we could do that." Listen, people. These responses are important.
Also, listen for the key phrases like "I miss you." or "Honey, Can you go to the kid's function tomorrow night?" or "Let's have a date." That means you need to pay more attention.
If he/she sends you a link to an article that suggests that playing age appropriate video games with the kids is a constructive way to build a relationship with them, then you need to think about that.
Make a list of priorities, in order of importance and then follow it. This is a simple version of my list, and you can put your stuff in there if you want.
4. My own workouts
5. Other stuff.
Obviously, it is more complex than that, but that is the idea. Now use your list. If you need to have a date night, then you need to figure it out. If rescheduling is necessary, work your way up from the bottom. I need a date night, so I am going to skip playing MMORPG, or something else. If i can't do that, then i am going to have to miss one of MY workouts to make time. This works. Especially since you dont have to have a conventional date. That is the thing. A good date time for me and my wife is on a weekend morning. That requires me to skip or move one of my workouts.
You can also think of it as a challenge to overcome. Then when someone says "I am IRONMAN" you can counter with, "Oh, yeah? I am one better. I am an IRONMAN, and still married."
That is my goal. To stay best friends and married to my favorite person in the world, to be a good role model to my kids, and to be a successful coach and athlete.