The answer is how many hours have you got available to do training in once you’ve factored in all your working, family commitments?
That is the amount of hours that you have available for training, and you can look at squeezing more in, but of inevitably something will give.
You don’t need to train as, as much as you might think.
Some people might be doing 25, 30 hours a week and training for an Ironman, which is basically like having a second job, as well as running a family and maintaining your relationship.
You’ve got to find, and this is where a coach, a good coach, will help you fit this in, how you maintain the balance between having your responsibilities outside of triathlon and having your hobby of triathlon.