title: Cardiovascular and hemodynamic responses on dryland vs. immersed cycling.
abstract: OBJECTIVE
  To investigate the effect of water immersion on oxygen uptake (VO2) and central hemodynamic responses during incremental maximal exercise at the same external power output (P ext) and recovery on an immersible ergocycle vs. a dryland ergocycle.
  
  
  METHODS
  Cross-over design study.
  
  
  METHODS
  Twenty healthy participants (32 ± 7 years; 173 ± 6 cm; 71.7 ± 9.7 kg) performed maximal incremental exercise tests while pedalling either immersed on immersible ergocycle (Hydrorider(®)) or on dryland ergocycle (Ergoline 800 S; Bitz, Germany). Initial P ext of dryland ergocycle protocol was set at 25 W and increased by 25 W every minute until exhaustion. P ext on immersible ergocycle was controlled by pedalling rate (rpm). Initial rpm was set at 40 rpm and was increased by 10 rpm until 70 rpm and thereafter by 5 rpm until exhaustion. Gas exchange and central hemodynamic parameters were measured continuously during exercise and a 5-min recovery period. Reported VO2, stroke volume, cardiac output (Q) and arteriovenous difference (C(a-v)O2) were compared.
  
  
  RESULTS
  During exercise on immersible ergocycle, VO2 and C(a-v)O2 were lower (P < 0.0001) whereas stroke volume and Q were higher (P < 0.05) relative to a dryland ergocycle exercise of equivalent P ext.
  
  
  CONCLUSIONS
  During exercise and recovery in immersion, (VO2) and arteriovenous difference were reduced in healthy young participants, while stroke volume and cardiac output were increased for the same P ext. During the recovery, central hemodynamics responses remained higher in immersible ergocycle.
authors.affiliation: Cardiovascular Prevention and Rehabilitation Centre (EPIC), Montreal Heart Institute, Canada; Research Center, Montreal Heart Institute and University of Montreal, Canada; Department of Kinesiology, University of Montreal, Canada.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Garzon
authors.affiliation: Cardiovascular Prevention and Rehabilitation Centre (EPIC), Montreal Heart Institute, Canada; Research Center, Montreal Heart Institute and University of Montreal, Canada; Department of Medicine, University of Montreal, Canada.
authors.forename: Martin
authors.initials: M
authors.lastname: Juneau
authors.affiliation: Cardiovascular Prevention and Rehabilitation Centre (EPIC), Montreal Heart Institute, Canada; Faculty of Sport Sciences, Laboratory MOVE (EA 6314), University of Poitiers, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Dupuy
authors.affiliation: Cardiovascular Prevention and Rehabilitation Centre (EPIC), Montreal Heart Institute, Canada; Research Center, Montreal Heart Institute and University of Montreal, Canada; Department of Medicine, University of Montreal, Canada.
authors.forename: Anil
authors.initials: A
authors.lastname: Nigam
authors.affiliation: Faculty of Sport Sciences, Laboratory MOVE (EA 6314), University of Poitiers, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Bosquet
authors.affiliation: Department of Kinanthropology, University of Quebec in Montreal, Canada.
authors.forename: Alain
authors.initials: A
authors.lastname: Comtois
authors.affiliation: Cardiovascular Prevention and Rehabilitation Centre (EPIC), Montreal Heart Institute, Canada; Research Center, Montreal Heart Institute and University of Montreal, Canada; Department of Medicine, University of Montreal, Canada. Electronic address: mathieu.gayda@icm-mhi.org.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Gayda
mesh_terms: D000328:Adult; D001642:Bicycling / Q000502:physiology*; D002302:Cardiac Output / Q000502:physiology*; D018592:Cross-Over Studies; D005080:Exercise Test; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007101:Immersion; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology*; D011897:Random Allocation; D013318:Stroke Volume / Q000502:physiology*
keywords: Central hemodynamic; External power output; Immersed ergocycle; Oxygen uptake; Pedalling rate