I belive that smooth muscles are the muscles of the heart and other organs.
Basically, your muscles needs at least 48 hours to recover, though this can vary a bit dependong on the person, their age, and any AAS use.
Some folks argue that the stomach is different, and the calves and the forearms are different becasuse they are used all the time.
But I would never work out any muscle five days a week.
I do a three way split (chest/back, shoulders/arms, legs/abs) and work out four days a week. So I get about five days reast before I hit the same exercise again (though there is some overlap in the muscles worked).
If you are not doing so already, start doing a two way, or three way split. If you want to work out more then, you could always add a day and still not hit the same body part too often.
But you need rest to grow, and if you overtrain, you will get worse results.