title: Physiological and perceptual responses to cycle and treadmill exercise during pregnancy.
abstract: We compared physiological and perceptual responses to non-weight bearing (cycle) and weight bearing (treadmill) exercise in 16 sedentary women throughout a normal term pregnancy. Subjects were recruited late in the first trimester (less than 13 wk gestation) and were studied at 4 wk intervals throughout pregnancy and 4 wk postpartum (PP). Exercise consisted of four 5 min protocols; two were performed on the cycle (C1 = 50 W; C2 = 75 W) and two on the treadmill (T1 = 66 m.min-1, 2.5% grade; T2 = 66 m.min-1, 12% grade). Measured variables included oxygen consumption (VO2), heart rate (HR), minute ventilation (VE), and ratings of perceived exertion (RPE, 10-point Borg scale). Absolute VO2 (ml.min-1) during cycle exercise increased (P less than 0.001) by 25 wk gestation, while relative VO2 (ml.kg-1.min-1) during treadmill walking was unchanged through late pregnancy and PP. This suggests that cycle exercise is not a true non-weight bearing exercise within a given group of women throughout gestation. Subjects' VO2max values were estimated at each test interval and found to increase (P less than 0.001) by 25-28 wk gestation. Heart rate and RPE responses to exercise remained constant throughout gestation and decreased (P less than 0.01) PP. Although they did not participate in a regular exercise program, it appears that our subjects experienced a mild aerobic training effect during late pregnancy.
authors.affiliation: Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, TX 77030.
authors.forename: J M
authors.initials: JM
authors.lastname: Pivarnik
authors.forename: W
authors.initials: W
authors.lastname: Lee
authors.forename: J F
authors.initials: JF
authors.lastname: Miller
mesh_terms: D000328:Adult; D001642:Bicycling; D001786:Blood Glucose / Q000032:analysis; D001794:Blood Pressure; D001835:Body Weight; D002245:Carbon Dioxide / Q000502:physiology; D002784:Cholesterol / Q000097:blood; D015444:Exercise / Q000502:physiology*; D005227:Fatty Acids / Q000097:blood; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007743:Labor, Obstetric; D010101:Oxygen Consumption / Q000502:physiology; D010465:Perception; D011247:Pregnancy / Q000502:physiology* / Q000523:psychology; D013990:Tidal Volume; D014280:Triglycerides / Q000097:blood; D016138:Walking
chemical_list: D001786:Blood Glucose; D005227:Fatty Acids; D014280:Triglycerides; D002245:Carbon Dioxide; D002784:Cholesterol