title: Pregnant women exercise at a higher intensity during 30 min of self-paced cycling compared with walking during late gestation: implications for 2 h postprandial glucose levels.
abstract: OBJECTIVE
  To compare the effect of an acute 30-min bout of self-paced stationary cycling (SC) with treadmill walking (TW) or a resting control (CON) on maternal blood glucose, insulin and metabolic responses during pregnancy.
  
  
  METHODS
  Twelve healthy women at 29.9±2.4 (mean±SD) weeks gestation consumed a 75 g carbohydrate drink as part of an oral glucose tolerance test (OGTT) following 30 min of SC, TW or CON. Blood was sampled before and after exercise, and for 2 h in response to the OGTT for the determination of glucose and insulin. Exercise intensity was monitored and enjoyment of TW and SC was assessed post-exercise.
  
  
  RESULTS
  Women selectively worked harder in SC compared with TW, with a higher maternal heart rate, rating of perceived exertion, mean oxygen consumption, respiratory exchange ratio, and total energy expenditure during exercise (p<0.05). SC was also associated with significantly lower postprandial blood glucose levels at 120 min following the OGTT (6.9±0.9 mmol∙l(-1)) compared with both CON (8.1±0.7 mmol∙l(-1), p=0.001) and TW (7.8±0.9 mmol∙l(-1), p=0.004) and lower insulin at 120 min post-glucose ingestion compared with TW (p=0.021). Enjoyment was similar between exercise protocols (p=0.437).
  
  
  CONCLUSIONS
  In late pregnancy, an acute 30 min bout of self-paced SC may be preferable to a matched duration of TW given the additional energy expenditure that can be achieved, which in turn appears beneficial for blunting the glycemic response to glucose ingestion.
authors: School of Sport Science, Exercise and Health, The University of Western Australia, Perth, Western Australia, Australia. halser01@student.uwa.edu.au
authors: Rhiannon E
authors: RE
authors: Halse
authors: Karen E
authors: KE
authors: Wallman
authors: John P
authors: JP
authors: Newnham
authors: Kym J
authors: KJ
authors: Guelfi
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000032:analysis*; D005080:Exercise Test; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D019518:Postprandial Period; D011247:Pregnancy / Q000378:metabolism*; D011262:Pregnancy Trimester, Second; D011263:Pregnancy Trimester, Third; D013997:Time Factors; D016138:Walking
chemical_list: D001786:Blood Glucose; D007328:Insulin