Peak ventilatory responses during cycling and swimming in pregnant and nonpregnant women. Spinnewijn, Wilhelmina E. M., Henk C. S. Wallenburg, Piet C. Struijk, Frederik K. Lotgering. Department of Obstetrics and Gynecology, Erasmus University School of Medicine and Health Sciences, Rotterdam, The Netherlands
APStracts 3:0134A, 1996.
This study was designed to determine if pregnancy affects peak oxygen uptake during swimming, compared to cycling. We studied 11 women at 30 - 34 wk gestation and 8 - 12 wk post partum. We measured heart rate (HR), oxygen uptake (VO2), carbon dioxide output (VCO2), minute ventilation (VE), and lactic acid concentration. Peak HR was not significantly affected by the type of exercise or by pregnancy. VO2peak was 9 % lower during swimming than during cycling but was not affected by pregnancy, with values for pregnancy cycling, pregnancy swimming, postpartum cycling, and postpartum swimming of 2.36 +/- 0.12, 2.11 +/- 0.11, 2.29 +/- 0.10, and 2.12 +/- 0.07 L/min, respectively. VCO2peak and VEpeak were significantly lower during swimming than during cycling by 18 -25 %, but only swim VCO2peak during swimming was affected by pregnancy (-10 %). Lactic acid concentrations were 12 - 17 % lower after swimming than after cycling and 17 - 31 % lower during pregnancy than post partum. We conclude that perceived maximal exertion is reached at a lower % VO2max in swimming than in cycling, and that the reduced energy expenditure is reflected by lower peak values of VO2, VCO2, and VE. Pregnancy, however, does not affect VO2peak in either cycling or swimming.

Received 15 September 1995; accepted in final form 16 February
1996.
APS Manuscript Number A1009-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 20 March 96