Pregnant person using weights at homeShare on Pinterest
Hobo_018/Getty Images

Pregnancy is a time of transformation for your body. Exercise can be a critical part of your new routine and help with anything from aches and pains to powering through labor.

Knowing what types of exercises are safe is key to staying injury-free and keeping you and your baby healthy throughout the next 9 months.

Do you like lifting weights? Well, resistance training can be a part of your workout plan — if you do it the right way. Here’s more on how much you should lift, what exercises to do and which to avoid, and what questions you should ask your doctor.

Unfortunately, there isn’t a one-size-fits-all answer to this question. If you regularly lifted weights before pregnancy, you very likely can continue with some modifications. If you’re new to lifting, you should probably speak with your doctor first.

In the first trimester of pregnancy, you may be able to continue with your routine without much change. However, as the weeks and months move forward, you may need to decrease your weight, change what moves you do, and try other tools, like resistance bands.

Related: What exercises are safe in the first trimester?

Weight training during pregnancy can be a great partner to other types of moderate exercise, like walking or swimming. Lifting weights strengthens muscles throughout the entire body and can help you feel better on the inside and out.

Researchers looked at a variety of studies on weight-bearing exercise and pregnant women and published their findings in the Strength and Conditioning Journal. Although the research is a bit older (from 2011), it still applies — and is comprehensive.

Researchers found that benefits include:

  • Better weight management. People who regularly exercise in pregnancy may gain 20 percent less weight than their less active counterparts.
  • Lower risk of gestational diabetes (GDM). People who exercise during pregnancy may also reduce their chances of developing GDM by up to 59 percent.
  • Lower risk of preeclampsia. Light exercise may reduce the incidence of preeclampsia by 24 percent. Vigorous exercise, on the other hand, may reduce it by as much as 54 percent.
  • Improved body image. Other studies noted in the 2011 research suggest that people who exercise throughout pregnancy often report a better self-image. Researchers found that sedentary folks often report feeling “fat” or “unattractive.” People who exercise 90 minutes a week or more have a “significantly” more positive body image.
  • Better mood. Along with this, feelings about body image, hormonal changes, and other shifts make pregnancy a prime time for depression. Exercise may mitigate this by releasing endorphins, which are powerful neurotransmitters that relieve pain and stress.
  • Protects against lower back pain. Up to 76 percent of pregnant women reported having back pain at some point during their pregnancies. Staying active — particularly focusing on the muscles in the trunk and core — may maintain better back health.
  • Helps with baby’s development. Babies of people who exercise regularly tend to be longer and leaner. Some studies show that resistance training, in particular, may be especially good in this regard. Beyond that, babies born to those who exercised vigorously during pregnancy actually showed “heightened attentiveness and discipline” when compared to controls.
  • Helps you power through labor. Along with a lower chance of cesarean delivery and preterm labor, people who do resistance training tend to have shorter active labors.

Overall, researchers have found that exercise has the power to make pregnancy and delivery a bit easier with fewer complications.

All people and all pregnancies are different. Even if you were active before pregnancy or in your last pregnancy, there are certain situations where your doctor may not give you the green light.

Plus, it’s important to remember that your body will change during pregnancy in ways you may not even realize.

  • The hormone relaxin loosens your joints and ligaments to prepare the body for delivery. All this new mobility makes you more prone to injury from overextending yourself with fast or high-impact movements.
  • Your balance changes as your center of gravity changes. You may be more prone to falling. This change may also put considerable strain on your lower back and pelvis.
  • Your oxygen needs increase when you’re pregnant. When you work out, oxygen and blood flow go to your muscles. You may become out of breath more quickly and you may find more vigorous exercise more difficult as a result.

There are also various complications you may encounter during your pregnancy. You’ll want to speak with your doctor before lifting or trying other types of exercise if:

  • you’re pregnant with twins, triplets, or other higher-order multiples
  • you have heart or lung disease
  • you have a cerclage in place
  • you’re 26 or more weeks pregnant and have been diagnosed with placenta previa
  • you’re experiencing preterm labor or your water has broken
  • you have preeclampsia
  • you have severe anemia

Related: How to safely exercise in the third trimester

There’s no clear safe and appropriate weight limit for all pregnant people. Instead, how much you can lift has to do with things like your previous fitness level, how far along you are, and how you’re feeling.

You’ll want to let your doctor or midwife know about your activity level before your pregnancy.

For some perspective, the American College of Obstetricians and Gynecologists even recommends that elite athletes — those who train at high levels more than 2 hours a day for several years in a certain sport — reduce their resistance load. There are no specifics given with regard to weight, however.

And while this research isn’t specifically about working out, scientists have looked at lifting heavy loads during pregnancy. People who repetitively lift at their jobs may be at risk of delivering their babies before 32 weeks.

Specifically, researchers found that lifting items over 20 kilograms (44 pounds) more than 10 times a day creates the highest risk of preterm birth.

Related: 17 pregnancy do’s and don’ts that may surprise you

You may be able to continue doing your usual lifting schedule, just be sure to check in with your doctor or ask a certified trainer for advice on modifications that may help as you and your baby grow.

Try lifting three times per week, focusing on the total body during your sessions versus splitting things up into target muscle groups (for example, hit multiple body parts versus just leg day).

Of course, you can do whatever you like in this regard, but you may experience more swelling in the areas you work.

Beyond that, the emphasis should be on more repetitions at a lower weight than you might be used to (70 percent of your max).

First trimester

In the first trimester, try these moves.

Muscle groupExerciseSetsRepetitions
BackLat pulldown2 to 310 to 15
ShouldersShoulder press2 to 310 to 15
ChestDumbbell chest press2 to 310 to 15
BicepsConcentration curl2 to 310 to 15
TricepsLying tricep extension2 to 310 to 15
Quads/glutesLunge2 to 310 to 15
Glutes/hamstringStiff-legged deadlift2 to 310 to 15
CalvesCalf raise2 to 310 to 15
CoreCrunch2 to 310 to 15
CorePlank2 to 3timed
CoreSide bridge2 to 3timed

Second and third trimesters

Your body and baby continue growing at a quick rate until delivery. Much of this weight may be around your midsection, making previous core exercises quite difficult to perform.

There are other considerations as well, like discontinuing moves that require you to lay flat on your back and compress the large vein that carries blood from your lower half to your heart (vena cava).

Try:

Muscle groupsExerciseSetsRepetitions
BackSeated row1 to 310 to 15
ShouldersLateral raise1 to 310 to 15
ChestSeated machine chest press1 to 310 to 15
BicepsDumbbell curl1 to 310 to 15
TricepsTricep kickback1 to 310 to 15
Quads/glutesDumbbell squat1 to 310 to 15
Glutes/hamstringCable back-kick1 to 310 to 15
CalvesStanding calf raise1 to 310 to 15
CorePlank1 to 310 to 15
CoreBird dog1 to 3timed
CoreSide bridge1 to 3timed

No matter what moves you do, be sure to focus on your form over how many reps you complete or weight you lift. Keeping good posture will protect your back and other muscles from injury.

You’ll want to steer clear of workout spaces that are hot or humid. The temperature could cause you to overheat, especially dangerous in the first trimester when many of your baby’s systems are developing.

Also avoid:

  • High-impact moves where there’s a risk of blunt force trauma. This may mean skipping exercise that involves hulking heavy free weights around your belly.
  • Lifting overhead after the first trimester. Why? Your posture changes, and lifting over your head may place strain on your lower back. To work those deltoids and rotator cuff muscles, try front raises, lateral raises, and reverse flies instead of shoulder presses.
  • Lying flat on your back after the first trimester. Again, it places pressure on your vena cava and can impact the blood supply to the placenta. This can make you feel dizzy.
  • Bending forward at the hips and/or waist after the first trimester. This may make you feel dizzy. As your belly grows, you may also find it hurts your lower back. Try instead an all-fours position if you’re looking to work those glutes and hamstrings.

Stop exercising right away and get in touch with your doctor if you experience vaginal bleeding or rupture of your membranes, or if you experience a decrease in your baby’s movements.

The following are other warning signs:

  • dizziness
  • headache
  • chest pain
  • weakness in your muscles
  • shortness of breath
  • pain or swelling in your calves

What about CrossFit?

If you’ve been doing CrossFit for quite some time, it may be OK to continue. Bring it up with your doctor at your next appointment. Experts share it may be fine to continue your favorite exercises as long as you’re under a doctor’s guidance.

That said, you may need to modify your routine as time goes on to keep you and baby safe. CrossFit WODs (workouts of the day) are scalable, so pay attention to how your body feels and consider lightening your load.

Related: CrossFit mom: Pregnancy-safe workouts

Above anything else, listen to your body. You may have days where you feel great and can smash even the hardest workouts. You may have others where something feels off or you’re simply more tired or sick than usual.

Other tips:

  • Aim to get 150 minutes of moderate-intensity exercise each week. Your effort should make you break a sweat, but you should be able to speak without getting out of breath.
  • New to exercise? Start small — even just 5 minutes of movement is beneficial. Over time, you can work your way up to exercising 30 minutes a day several days a week.
  • Stay hydrated. You should aim to drink 10 cups of fluids a day — more after exercise. Good choices include water, non-caffeinated tea, milk, and juices.
  • Consider using resistance bands if weights are getting awkward. These stretchy bands allow you to work with some tension with more comfort.
  • Better yet, consider resistance exercises that use your own body weight instead. Search YouTube for free workouts, like this 25-minute pregnancy workout from BodyFit by Amy, or ask a certified trainer for moves appropriate during pregnancy.
  • Try wearing a belly band for extra support during exercise as your stomach grows. Belly bands can be worn under or over your clothing and are relatively flexible, so they move with you.

Related: What exercises are safe in the second trimester?

Weight training can be a safe part of your pregnancy exercise routine. Speak with your doctor about your current fitness level and your goals.

Consider scaling back your weight and focusing on your posture to avoid low back pain and muscle strain. Pay attention to how your body is feeling each time you exercise and change your routine accordingly. And if you experience any warning signs, take a step back and reevaluate.