So often I hear my clients say "Oh, I (insert activity here: chase the kids around, run around at work) all day, I don't need to workout. My life is a workout!", or something along those lines. Let me say this once and for all, it is NOT the same as dedicated exercise. In fact, I think this is looking at it backwards.
Dedicated exercise is exactly what prepares you to do these activities, not visa versa. Everyday activities are exercises yes- in fact the exercises we do more often than not mimick everyday movements. They are designed for that sensible reason. When you are lugging laundry up 2 flights of stairs or chasing a toddler in a half squat jog you don't have mental capacity or control to focus on your form.
Dedicated exercise is our opportunity to establish strong form in our range of motions, so that when we are on the move in real life we will carry that form automatically. This helps to keep us from being injured and to be more effective in our movements.
Clear as mud, right?