If your job allows, cut back on your hours. Lying down frequently, especially on your left side, also relieves swelling, another side effect of late pregnancy. You can also ease swollen ankles and calves by sitting with your feet elevated and not standing for long periods. Just make sure you listen to your body. If you're tiring sooner, don't power through a workout as hard as you did mid-pregnancy.
Swimming also relieves pressure on the nerve.
After exercising, indulge yourself. But if the thought of even rising from an armchair seems like a workout, just stay put. By the eighth month of each of her two pregnancies, Jessica Smith, of Cincinnati, found it impossible to sleep well on her water bed. I couldn't lie right, I couldn't even sit right on it. So she slept on the firmer couch, using a pillow to cushion her stomach.