Effects of exercise on plasma lipids and metabolism of lactating women.
To examine the effects of exercise on plasma lipids and metabolism during lactation, sedentary, exclusively breast-feeding women were randomly assigned to an exercise (E) or control (C) group at 6-8 wk postpartum. E subjects performed aerobic exercise 45 min.d-1, 5 d.wk-1, for 12 wk. Resting metabolic rate (RMR), energy expenditure, body composition, and dietary intake were measured at 6-8, 12-14, and 18-20 wk postpartum. Maximum oxygen uptake (VO2max), postprandial insulin, glucose, and thermic response, and plasma lipid levels were measured at 6-8 and 18-20 wk. VO2max increased by 25% vs 5% in the E vs the C group, respectively (P < 0.0001). RMR was similar between groups and did not change over time. Weight and percent body fat declined (P < 0.01) during the study, but there was no difference between E and C groups. Exercise marginally increased high-density lipoprotein cholesterol levels (P < 0.08), but did not affect other lipid concentrations. Insulin response decreased as VO2max increased (P = 0.05). There was no effect of time or group on glucose or thermic response. Exercise improves cardiovascular fitness during lactation, but does not increase the rate of postpartum weight loss.
Lovelady
C A
CA
Department of Nutrition, University of California, Davis 95616-8669.
Nommsen-Rivers
L A
LA
McCrory
M A
MA
Dewey
K G
KG
D000273:Adipose Tissue / Q000033:anatomy & histology; D000328:Adult; D001481:Basal Metabolism / Q000502:physiology; D001786:Blood Glucose / Q000032:analysis; D001823:Body Composition / Q000502:physiology; D001833:Body Temperature Regulation / Q000502:physiology; D001942:Breast Feeding; D008076:Cholesterol, HDL / Q000097:blood; D004032:Diet; D004734:Energy Metabolism / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D007774:Lactation / Q000502:physiology*; D008055:Lipids / Q000097:blood*; D010101:Oxygen Consumption / Q000502:physiology; D010809:Physical Fitness / Q000502:physiology; D015431:Weight Loss
D001786:Blood Glucose; D008076:Cholesterol, HDL; D007328:Insulin; D008055:Lipids