PURPOSE: We investigated the effects of acute plasma volume expansion on exercise performance in the heat. METHODS: Six moderately trained men cycled for 40 min at 64 +/- 2% peak pulmonary oxygen uptake (VO2peak) followed by an individual performance time trial, where subjects completed a set amount of work (267 +/- 15 kJ) in as little time as possible. Exercise trials were performed at 35 degrees C with a relative humidity of 40%. Subjects performed two exercise trials: one after 13.1 +/- 1% acute plasma volume expansion (PVE), which was achieved by the intravenous infusion of 8 mL x kg(-1) body weight of Hemaccel (35 g x L(-1) polygeline, 145 mmol x L(-1) Na+, and 145 mmol x L(-1) Cl-) and the other without prior treatment (CON). RESULTS: Core temperature, skin blood flow, and heart rate progressively increased (P < 0.05) during exercise, but no differences were observed between trials. Plasma glucose and lactate were similar at rest and during exercise, as was VO2 during exercise. Exercise performance was not influenced by plasma volume expansion (CON 17.5 +/- 0.4 min and PVE 17.1 +/- 0.2 min). CONCLUSION: These data suggest that, in moderately trained men, plasma volume expansion alone does not enhance thermoregulatory function and exercise performance during moderate intensity exercise in the heat.
PURPOSE: We investigated the effects of acute plasma volume expansion on exercise performance in the heat. METHODS: Six moderately trained men cycled for 40 min at 64 +/- 2% peak pulmonary oxygen uptake (VO2peak) followed by an individual performance time trial, where subjects completed a set amount of work (267 +/- 15 kJ) in as little time as possible. Exercise trials were performed at 35 degrees C with a relative humidity of 40%. Subjects performed two exercise trials: one after 13.1 +/- 1% acute plasma volume expansion (PVE), which was achieved by the intravenous infusion of 8 mL x kg(-1) body weight of Hemaccel (35 g x L(-1) polygeline, 145 mmol x L(-1) Na+, and 145 mmol x L(-1) Cl-) and the other without prior treatment (CON). RESULTS: Core temperature, skin blood flow, and heart rate progressively increased (P < 0.05) during exercise, but no differences were observed between trials. Plasma glucose and lactate were similar at rest and during exercise, as was VO2 during exercise. Exercise performance was not influenced by plasma volume expansion (CON 17.5 +/- 0.4 min and PVE 17.1 +/- 0.2 min). CONCLUSION: These data suggest that, in moderately trained men, plasma volume expansion alone does not enhance thermoregulatory function and exercise performance during moderate intensity exercise in the heat.
Authors: Rocío A Figueroa; Amy C Arnold; Victor C Nwazue; Luis E Okamoto; Sachin Y Paranjape; Bonnie K Black; Andre Diedrich; David Robertson; Italo Biaggioni; Satish R Raj; Alfredo Gamboa Journal: J Appl Physiol (1985) Date: 2014-07-24
Authors: Sébastien Racinais; Juan-Manuel Alonso; Aaron J Coutts; Andreas D Flouris; Olivier Girard; José González-Alonso; Christophe Hausswirth; Ollie Jay; Jason K W Lee; Nigel Mitchell; George P Nassis; Lars Nybo; Babette M Pluim; Bart Roelands; Michael N Sawka; Jonathan Wingo; Julien D Périard Journal: Sports Med Date: 2015-07 Impact factor: 11.136
Authors: S Racinais; J M Alonso; A J Coutts; A D Flouris; O Girard; J González-Alonso; C Hausswirth; O Jay; J K W Lee; N Mitchell; G P Nassis; L Nybo; B M Pluim; B Roelands; M N Sawka; J Wingo; J D Périard Journal: Br J Sports Med Date: 2015-06-11 Impact factor: 13.800