If you've just had a baby, then your body is working in overdrive to not only provide for your newborn but also mend itself from the marathon of pregnancy and the physical trauma of childbirth. More than anything, your body needs rest. And while it may seem counterintuitive, getting enough sleep is important for weight loss. Sleep is difficult to come by in those early days, so take the opportunity whenever it presents itself. Prior to having my son, I would sacrifice sleep for workouts, waking up at the crack of dawn to get in a sweat session. This never happened during my fourth trimester because it was not a healthy decision.