If you say you are going to start working out, do it.
About a month ago I told my wife that I was going to start waking up early and go for a job everyday at 6 AM. And everyday for the last month I have been sleeping to at least seven and only going for walks with the dog a couple times a week.
If you tell your wife you are going to do something you need to do it. If you tell her you are going to work out you need to make sure you do it so that she will not be doubly disappointed when you turn out to be a couch potato rather than someone who is working on turning themselves into a hot tamale.
So get up and go work out...well, maybe tomorrow.