This applies particularly to fans of weight lifting. It is common advice to avoid lifting heavy objects as your pregnancy progresses; so your exercise routine is going to adjust. You want to protect your growing bump, after all! Luckily, there are plenty of ways to modify your workouts without sacrificing any sweat. Here is what you need to know about lifting weights safely during pregnancy.

Lifting Weights While Pregnant

The American College of Obstetricians and Gynecologists lists resistance exercise, including lifting weights, as safe during pregnancy. Experts agree, so long as you first clear it with your healthcare provider and are not experiencing any pregnancy-related health conditions. You will need to follow the best practices for working out when pregnant; lifting lighter weights, paying closer attention to your form, or trying new routines to accommodate your changing ability. You may also consider consulting a pre-natal certified fitness professional. If you are completely new to lifting weights, then pregnancy is not the time to begin an extreme program, according to David Kirsch, a New York-based celebrity trainer and best-selling author. Instead, try out lighter exercise routines, like prenatal yoga or walking.

Benefits

Lifting weights during pregnancy not only can help you stay fit, but it can help you prepare your body for parenthood. “When done correctly and with the appropriate weight, strength training is quite beneficial," explains Andrea Chisholm, MD, a board-certified OB-GYN in Cody, Wyoming. “It will help with posture changes, protect your core and lower back, and help build or maintain endurance. This is something you will definitely need for labor.” Here are the benefits of weight training when you’re expecting.

Strengthens Back Muscles

Lower back pain is a common complaint during pregnancy, affecting approximately two-thirds of all pregnant people. This is because a growing uterus and enlarged breasts can shift your center of gravity and increase the curvature of your back, which puts extra strain on the back muscles. Lifting weights can strengthen back muscles and increase core strength, which helps support the additional weight of your changing body.

Easier Labor

Research shows that exercise, particularly resistance training, has a positive effect on labor outcomes. It can decrease the chance of cesarean delivery and decrease the length of a hospital stay; lower the chance of an instrumental delivery; shorten the early stages of labor. And try not to worry about going into early labor because of your workout; studies also show that resistance exercises do not increase the risk of preterm labor.

Better Weight Management

Pregnancy weight gain is expected and important to support the growth of your baby. Too much weight gain, however, may lead to health problems, like gestational diabetes and hypertension while increasing the risk of obesity in your child. It can also increase your risk of obesity after pregnancy. Too little weight gain can lead to your child being too small; this increases their risk of illness and may lead to developmental delays. Research shows a regular exercise program, including strength training with weights, can help control excess weight gain during pregnancy. There is also evidence that maintaining a lower weight during pregnancy can help prevent preeclampsia.

Lowers the Risk of Gestational Diabetes

Pregnancy can also put you at risk of developing gestational diabetes mellitus (GDM), a form of diabetes that occurs during pregnancy. Usually, high blood sugar levels return to normal after pregnancy, but GDM can increase your risk of developing type 2 diabetes later in life. It can also increase your baby’s risk of obesity, impaired glucose tolerance, and type 2 diabetes. Including resistance training in your prenatal workouts has been shown to lower the risk of developing GDM. Resistance training also protects babies born to people with GDM. It reduces the incidence of macrosomia—when a newborn weighs more than eight pounds 13 ounces at birth—which can cause difficulties during labor and increase the risk of caesarian delivery.

Precautions

Every pregnancy is different. Your physiological condition and health will determine the type of exercises you can perform during pregnancy.  However, there are certain precautions you should take when you are starting any workout routine during pregnancy, including weight training. These measures reduce the risk of complications and injuries to you and your baby.

Avoid Lying on Your Belly or Back

Laying on your back in the second and third trimester causes the uterus to compress the vena cava, a major vein that carries deoxygenated blood to the heart. This reduces the flow of blood oxygen to the baby. Avoid exercises in a supine position, like bench press or prolonged floor work. Instead, modify your position so that you are inclined, sitting, or upright. For example, a chest press can be performed on an incline bench after 12 weeks. After 20 weeks you can practice it with a further incline. It is also important not to use machines that place excessive strain on your lower back and those with a pad that presses down on your belly.

Be Careful of the Abdominals

During pregnancy, the muscles that meet in the middle of your stomach stretch to create space for a growing uterus. It is common for the rectus abdominis to separate; this is called diastasis recti (DR). DR can also be caused by incorrectly lifting heavy weights or performing unsafe or excessive abdominal exercises. This includes moves that require you to lie on your belly after the first trimester. Many trainers recommend focusing on strengthening the pelvic floor and core muscles, rather than traditional ab exercises.

Use Lighter Weights

During pregnancy, the placenta produces a hormone called relaxin, which loosens your joints and ligaments in preparation for delivery. As a result, any high-impact exercise, including weight training, can make you more prone to injury, strains, and sprains. To avoid overloading loosened joints, trainers suggest using lighter weights and doing more repetitions. Kirsch recommends working in the 10 to 12 rep range. It is also vital to be mindful of overstretching and maintaining a strong lower back, he says. If you are unsure about using weights and still want to include resistance training in your workout, try bodyweight exercises; using your body as resistance to build strength.

Avoid Lifting Weights Above Your Head

As the uterus shifts forward, it also changes the orientation of the pelvis and may cause further stress on the lower back and pelvis. Additionally, weight gain is focused on your midsection during pregnancy, which changes your center of gravity. This alters your posture and balance, which can lead to an arched lower back, slouched shoulders, and lower back pain. Lifting weights above your head can increase the curve of your lower spine and exacerbate lumbar stresses. Avoid exercises like shoulder presses after the first trimester. “Putting your pregnant body under too heavy a load can lead to joint and low-back injury because of postural and hormonal changes,” says Dr. Chisholm. “It can also injure your weaker abdominal muscles and strain the muscles of your pelvic floor.” Instead, you should focus on the stabilization of the pelvic floor and strengthening your core, hips, and back to support better posture and maintain balance.

Avoid Vigorous Exercise

Repetitively lifting heavy weights during pregnancy can cause you to hold your breath—which needs to be avoided at all costs. While pregnancy, blood flow significantly increases to the uterus, feeding oxygen-rich blood to the placenta. During moderate exercise, blood is diverted from your organs to your muscles, but the circulation of placenta blood is maintained. During vigorous exercise though, the blood flow to the placenta is reduced; this results in a decrease in oxygen going to the fetus. The resultant disrupted flow of oxygen is not only dangerous for your baby, but it can make you lightheaded and lead to cramping. Additionally, repetitively lifting heavy weights can increase abdominal pressure and overload your pelvic floor muscles.

Weight Training Routine During Pregnancy

There is no one-size-fits-all routine for lifting weights during pregnancy. Your weight training routine and the amount of weight you can lift depends on your previous fitness level, your weight training experience, how far along you are in your pregnancy, and your current health condition. If you are already using a strength training program, consider lifting to maintain rather than build more strength. You can do this by using lighter weights with higher reps. Kirsch recommends weight training two or three times a week for a full-body workout rather than focusing on one or two specific body parts. “Focus on exercises that help with postural alignment and maintaining a strong back and proper breathing during exercise is very important,” he says. Those new to weight lifting should take it particularly easy. “If you are a novice to strength training, perhaps sticking with light resistance training is your best bet,” says Dr. Chisholm. Kirsch recommends doing this with resistance bands instead of weights.

When to Call a Doctor

It is important to stop exercising and call your doctor immediately if you experience any of these symptoms:

Vaginal bleedingAmniotic fluid leakDecrease in your baby’s movementsPreterm laborDizzinessHeadacheShortness of breathChest painCalf pain or swellingWeakness in your muscles