Life for baby is all about playtime! Baby’s laughing and reaching -- and doing tons of gnawing. While you two play on the floor, baby is probably showing off some newfound athletic abilities, such as rolling and pushing up. Not getting yourself to the gym, mama? Baby is showing you how it's done (and he has the growth to show for it)! Use him as your own little motivator and personal-trainer-in-the-making. Why not get down on the floor and do some exercises of your own?