
Pregnancy and exercise is a hotly debated topic. There are so many conflicting messages out there, it's hard for pregnant women to feel confident that they’re choosing the smartest approach. In this article, we get to the bottom of the common myths around exercise and pregnancy, arming you with important information that will help you feel safe and comfortable while being active.
• The facts about weight gain during pregnancy
• How to lower the likelihood of diabetes, pre-eclampsia and hypertension when pregnant
• The best exercise for easing anxiety while pregnant
• How to use physical activity to reduce the risk of post-partum physical depression
Disclaimer: It’s really important that you consult your doctor about your plans for being active. You should explain the nature of the training you would like to do, and keep them updated with how you feel during exercise. And if you have medical or obstetric complications you must be evaluated before participating in any physical activity .
Pregnancy is a special time. Your body is going through phenomenal change, so is it wise to add exercise into the mix?
Fitness researcher, Bryce Hastings, says “Embarking on lofty new fitness challenges is probably not a good idea, but that doesn’t mean avoiding exercise altogether.” He explains that the latest guidelines encourage regular exercise before, during and after pregnancy – for both active and sedentary women. In fact, they urge previously inactive women to take up some form of exercise, suggesting that this is the perfect time to make healthy lifestyle changes.

Other benefits can include having babies that are alert, calm, self-quieting, and better able to cope with the stresses of labor. It's also worth noting that neglecting exercise and gaining too much weight during pregnancy can place extra stress on the joints and contribute to an increase of lower back pain.
On a mission to shed even more light on the value of exercise during pregnancy, UK‑based fitness professional Mike Trott has taken a deep dive into an American College of Sports Medicine (ACSM) umbrella review . This comprehensive review synthesizes decades of global research on exercise and pregnancy and, drawing on the scientific findings, Trott highlights the key takeaways and evidence‑based recommendations for exercising safely and effectively during pregnancy.
Weight gain is a given in pregnancy, but how much should you gain? Luckily, there are official guidelines, fully detailed here . As a guide, a woman with a normal BMI (18.5-24.9) should expect normal gestational weight gain of 11.5-16kg. Anything more than that would be considered excessive, and anything under that would be considered less than desirable. There is very strong evidence suggesting that exercising during pregnancy reduces excess weight gain. The evidence shows that moderate intensity cardiovascular exercise (such as aerobics, walking and swimming) for 30-60 minutes at least three times a week significantly decreases the chances of excess weight gain during pregnancy.
Gestational diabetes is a condition in which a mother with no evidence of diabetes pre-pregnancy develops high blood sugar levels during pregnancy. Although many expectant mothers do not experience symptoms as a result, gestational diabetes increases the risk of pre-eclampsia, depression, and requiring a caesarean-section. There is very strong evidence that exercising during pregnancy decreases the risk of developing this condition by 27 percent on average. Even better, though, exercising before and during pregnancy further decreases the risk of developing the condition by 38 percent.
Pre-eclampsia is a condition in which an expectant mother experiences high blood pressure and high levels of protein in the urine, especially during the second half of pregnancy. The evidence surrounding exercise and these conditions suggests there is a dose-response relationship the risks of developing the condition lower as the amount of weekly exercise increases, until about five hours per week, where if the expectant mother did more exercise, the decrease in risks get smaller, with studies suggesting that five hours/week is the sweet spot.
Anxiety can affect expectant mothers both pre and post-partem and can have a large impact on the mental health of the mother. The evidence suggests that practising yoga during pregnancy can significantly reduce various forms of anxiety.
Depression is a major concern for mothers, and exercise has been shown to help both during and after pregnancy. Studies have shown that practising yoga during pregnancy can reduce symptoms of depression, plus moderate intensity aerobic exercise post-partem has been shown to reduce the incidence of post-partem depressive symptoms.
Almost all of the evidence suggests that exercising during pregnancy yields many benefits for both mother and baby. Aerobic based exercise 3-5 times per week potentially yields the most benefits, with the addition of yoga yielding extra mental health benefits too.
One of the key things for the expectant mother though is to listen to their body. If you don’t feel right exercising, stop straight away, and if you don’t feel like exercising one day (or one week, or even one month!), it’s okay. Just get back into it when you feel ready.

So now you know all about the benefits of staying active during your pregnancy, check out which LES MILLS™ programs are the best while you're expecting, and some pregnancy modifications you can make to make them safe for you and your baby.
You can find a class near you or jump onto the LES MILLS+ fitness app and get 24/7 unlimited access to online workouts, including specific workouts and advice for moms-to-be and new moms.
Mike Trott is a UK-based fitness professional who specializes in sports personality psychology and sports exercise physiology. He has conducted academic research into group exercise interventions and personality, exercise addiction, and foam rolling physiology, and is also a multi-award-winning Les Mills instructor, trainer and presenter.
Bryce Hastings is a leading New Zealand physiotherapist and fitness expert. As Les Mills Head of Research he has has developed numerous research programs and co authored reports across a range of fitness and scientific publications. Working closely on the development of workout programming, Hastings bridges the gap between the lab and the gym floor, ensuring every LES MILLS™ program is safe, effective, and powered by science.