Carrying a baby belly around is like a mini boot camp for your muscles. It's not so bad in the first trimester, but as your belly size increases, so does the strain on your back, thigh and core muscles. Those muscles get put to the test again during labor, when pushing will require all the strength you can muster. The stronger your body, the better it tolerates and adapts to these changes. Weight training is an efficient way to keep your muscles strong during pregnancy. It's a safe exercise for the first trimester and beyond, according to the American Pregnancy Association, as long as you follow some specific guidelines.
Maintenance, not Mass
The goal of any pregnancy weight training routine should be muscle maintenance. If you lifted weights regularly before pregnancy, you should continue lifting just enough weight to keep your muscles strong, not to gain new muscle mass. If you've never lifted weights before, you'll need to either work with a trainer who has experience working with pregnant women or build muscle through a lower-risk activity, such as prenatal yoga.
Risks
Your body naturally is more prone to injury when you're pregnant. Hormonal changes loosen your joints and stretch your muscles, so lifting too much weight or lifting weights incorrectly can lead to muscle tears, joint injuries and falls. If you don't know much about weightlifting, you could dangerously increase your blood pressure, limit the blood supply to your baby or even drop a weight on yourself. You don't have to be clumsy or inept to drop a weight, either. If you push too hard, you could become dizzy or experience pain that affects your grip. Pregnancy is not the time to push yourself, even if you don't "feel pregnant" because it's only the first trimester.
Safe Training
It's best to lift with a trainer or a trusted friend, for safety reasons. Once you get started, you'll want to choose weights that are much lighter than you normally use. Even if you're a more experienced lifter, you'll still want to start really low and work up slowly to make sure you don't injure yourself. You know you're using the right amount of weight when you can get through your set without any straining but still feel your muscles working. If increased reps don't work, increase your weight, but by only a few pounds, until you find that sweet spot where you feel your muscles working but you're not straining.
What to Avoid
Skip lunges, dead lifts and similar activities because they pose the biggest risk of pelvic tissue and joint injuries, according to BabyCenter fitness expert Tracey Mallett. Never hold your breath or you could cause a dangerous spike in your blood pressure. Don't spend more than a minute or two on your back at one time, as you'll compress a major blood vessel that supplies oxygen and nutrients to your baby. Ask your trainer about other ways to work similar muscle groups that don't require lying on your back, and avoid lying on your back altogether after the first trimester.
