Doctors have been hesitant to endorse strength training during pregnancy for years due to the lack of research proving that strength training is safe and healthy for pregnant women. One of the primary concerns for doctors is the increase in the hormone relaxin during pregnancy. This hormone relaxes the body's connective tissue as the woman prepares for childbirth, making doctors question whether pregnant women could be more susceptible to musculoskeletal injury while strength training.
Luckily, new research from the University of Georgia puts some of those fears to rest. Even if you've never lifted weights before, many pregnant women can feel good about starting a strength-training routine without worrying about injury.
The Research and Results
Researchers led by Patrick O'Connor from the University of Georgia's kinesiology department, recruited 32 previously untrained pregnant women to participate in a 12-week low-to-moderate intensity strength-training program. Each week the women performed a series of six exercises known for their association with decreased back pain. After a total of 618 exercise sessions, or approximately two sessions per woman, per week, none of the women experienced musculoskeletal injuries, and they all experienced strength gains.
Some of the interesting statistics included:
- The average strength gain over the 12-week period was 36 percent on each exercise performed.
- On only 13 separate occasions during the 618 exercise sessions (two percent of all exercise sessions), women reported potentially problematic symptoms including pelvic pain, dizziness and headache—dizziness symptoms were considered the most concerning.
- Problematic symptoms decreased over time as the women learned to breathe properly while lifting weights.
- Blood pressure did not increase or decrease due to strength training.
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