High-Intensity Resistance Training During Pregnancy
Researchers note safety findings may lead to updated training guidelines.
Good news—researchers are supporting women to train with confidence during pregnancy by testing whether higher intensity exercise activities are harmful or helpful for expectant mothers. Turns out, high-intensity resistance training is safe for both expectant mothers and unborn babies, as reported in the British Journal of Sports Medicine (2025; doi: 10.1136/bjsports-2024-108804). Researchers from the University of Alberta in Canada studied 10 healthy pregnant women and 10 healthy non-pregnant women to compare their responses, as well as the fetuses’ responses, to high-intensity weight training that included the Valsalva maneuver, immediately before and after exercise. Data analysis showed a similar response among both groups of women and no negative effects on the fetus.
“Previously it’s been discouraged [for pregnant women] to lift heavy weights, to use the Valsalva maneuver, but there’s not a lot of empirical evidence around it,” says lead study author Amy Moolk, master’s student in the Faculty of Kinesiology, Sport and Recreation and former Olympic weightlifter, at University of Alberta. “We want women to stay active during pregnancy, but our specific recommendations are lacking because we don’t have the evidence. This is going to contribute to providing better guidance and recommendations and it can help women continue to engage in activities they enjoy.”
Shirley Eichenberger-Archer, JD, MA
Shirley Eichenberger-Archer, JD, MA, is an internationally acknowledged integrative health and mindfulness specialist, best-selling author of 16 fitness and wellness books translated into multiple languages and sold worldwide, award-winning health journalist, contributing editor to Fitness Journal, media spokesperson, and IDEA's 2008 Fitness Instructor of the Year. She's a 25-year industry veteran and former health and fitness educator at the Stanford Prevention Research Center, who has served on multiple industry committees and co-authored trade books and manuals for ACE, ACSM and YMCA of the USA. She has appeared on TV worldwide and was a featured trainer on America's Next Top Model.
