Your body is more complex than you think. If you push it daily, the muscles will respond and never go into a healing phase which is when actual growth happens. When you take a day off, the muscles notice this and allow themselves to go into a healing phase. The healing phase makes the muscle less able to respond, so it only does this if it thinks it won't be stressed again.
A long time ago I would work out everyday and I actually got better results when I only worked out certain muscle groups once a week instead of 2-3 times a week. However, if you work out everyday, you will carry a bigger "pump" and feel bigger, but you will get stronger much more slowly.
The above is for heavy workouts, if your workout doesn't make you sore then you can probably do it everyday as a maintenance type of thing.
|