Pregnancy and Your Fitness
From The Thinking Parent newsletter
Physical fitness and strength levels may decline in pregnant women. Compared to pre-pregnancy levels, a study finds that fitness and strength are lower at six weeks postpartum. However, fitness and strength begin to improve by 27 weeks postpartum.
What the researchers did
A longitudinal study of 63 women examined changes in physical activity, fitness and strength before and after pregnancy. Most women were white. They were evaluated before pregnancy and at six and 27 weeks postpartum. The women were grouped based on body mass index (low, average, high). The sample included only women who delivered one baby at term.
Body composition, physical fitness and strength were measured objectively at each time point. Fitness was measured by a maximal oxygen consumption test on a cycle ergometer. Strength was assessed by a one-repetition maximum test (weight lifting). Also, participants completed questionnaires reporting physical activity at each time point.
What the researchers found
Total levels of physical activity were unchanged from pre-partum to postpartum. However, changes occurred in amount of time spent in specific activities. Conditioning exercises, water activities, sports, occupational activities, dancing and bicycling were lower postpartum. Winter activities, gardening, fishing and sleeping were unchanged. Walking and home activities increased postpartum. Thus, total levels of activity did not change from pre-partum levels, but the type of activity did.
Fitness and strength levels, in general, were lower in the postpartum period as compared to pre-partum. Specifically, maximal oxygen consumption and leg and arm strength decreased from pre-pregnancy to six weeks postpartum. Some of these decreases were returning at 27 weeks postpartum but were not at pre-pregnancy levels. These changes occurred across women with different body mass indices (that is, strength and fitness levels decreased among all women, regardless of whether they had a low, medium or high body mass index).
What this means for you
Physical fitness and strength levels declined across all body sizes and fitness levels. Overall physical activity levels did not change, but the type of activity changed. These changes were presumably due to the demands of being a new mother.
Pregnant women are encouraged to remain as physically active for as much and as long as possible during pregnancy in order to maintain the health benefits of exercise and to minimize the decreasing levels of fitness and strength.
Source: Treuth, M.S., Butte, N.F., & Puyau, M., May 2005, “Pregnancy-related changes in physical activity, fitness and strength,” Medicine and Science in Sports and Exercise, 37, 832-837.
© Jennifer Hahn
NFO contributor Dr. Jennifer Hahn is the editor of The Thinking Parent, a quarterly publication reviewing research of interest to parents: child development and parenting, pregnancy and childbirth, physical health, mental health and education. With more than 12 years of experience in research at the Johns Hopkins School of Medicine, Dr. Hahn received her Ph.D. from the University of Maryland Baltimore County and completed her residency at the University of Virginia Health Sciences Center. She is the mother of two daughters.
