I think it's healthy and even important for both partners to have "other interests" besides each other. That makes a person more "well rounded" as an individual.
The problem arises when there is a lack of balance/moderation.....and little attention is being given to the relationship and other responsibilities int he marriage. If that's the case.......then you talk to your spouse about the matter in a calm way.....and see if you can come up with ways to resolve the issue.....such as schedule adjustments or sharing the responsibilities to manage time better, etc. Asking or pressuring your spouse to give up their interests entirely is not fair and it can create problems. Rather, discuss feeling in a non-defensive manner and come up with possible solutions.
^Even then.......he needs to talk about the issue with his wife. Maybe they need to work out a schedule. If her other interests are leaving her exhausted....then he could help her out with household chores (for example)......and that way she'd feel less tired and have more time for the various aspects of marriage (including sex).
Now....I'm not a 100% sure....but I think Uzziel has created a few threads in the past regarding his wife and the more intimate aspects of their marriage. I think (not sure) I vaguely recall even a thread saying that she had "too much" sexual energy. Since it seems like a frequent topic....I wonder if it might be trolling.
maybe you need to romance her a bit! Compliment her! A woman will never get tired of hearing "you look beautiful", "you are beautiful" and other such compliments. Take her out for a romantic dinner, a romantic stroll along the beach/lake or in downtown.
Also, a lot of women these days work full time and run a house...maybe she is tired! Help her around the house with whatever you can.
On Saturday, take her out to the theater (not movies, theater to see a play), then go for a romantic dinner at a nice restaurant (it doesnt have to be expensive, just nice), take a stroll downtown, hold her hand, compliment her, talk to her about her day, try to laugh and enjoy the evening......
if that doesnt work....then you must have done something to really piss her off, and the only remedy is a nice piece of jewelry!