The second trimester is usually the best trimester for working out. All of a sudden you're going to feel like you have a lot of energy. You should feel less nauseous all the time. The only thing you may feel is a little bit of a Braxton Hicks contraction. It's just a gentle, kind of preparatory contraction of the uterus. Nothing to be too worried about. As always, drink lots of water. Avoid overheating. You also may find it's a little bit more uncomfortable even in the beginning of your second trimester to be belly down. Once it's uncomfortable, don't be belly down anymore. Also, later in the second trimester, you may feel uncomfortable being flat on your back. It's very simple. Just get a little incline or you can lay on one side as you do your workouts. You also want to avoid doing any forceful contractions of your transverse abdominus muscle. It's the muscle that runs horizontally across your belly. Avoiding that will avoid any further pressure on the baby that it may not enjoy. As the belly increases in size, as the baby starts to grow in weight, you're going to notice postural shifts. You may notice that your belly is hanging out. Your butt is sticking out a little more. That's very normal, but you will have to adjust your posture, adjust how you work out to minimize the discomfort in your lower back and hips. In terms of improving your posture as your belly grows, just be more conscious of it. Your lower back is gonna sway out, but you can think about dropping your hip bones and gently hugging the baby with your muscles and your stomach.