Cardiovascular drift and Vo2max during cycling and walking in a temperate environment.
BACKGROUND
Different muscle recruitment patterns during cycling and walking may influence the magnitude of cardiovascular drift (CV drift) during these respective modes of exercise, but whether this also influences the magnitude of reduced maximal oxygen uptake (Vo2max) associated with CV drift is unknown.This study tested the hypothesis that cycling results in greater CV drift and a greater decrement in Vo2max than walking in a temperate environment.


METHODS
CV drift was measured in nine recreationally active women (ages = 23 +/- 2 yr, Vo2max = 43.0 +/- 5.5 ml x kg(-1) x min(-1)) between 15 and 45 min of cycling or walking at 60% Vo2max on Separate occasions in 22 degrees C, 44% relative humidity. A graded exercise test to measure Vo2max was performed immediately after the submaximal exercise bout with no cessation of exercise. During separate trials involving each exercise mode, Vo2max was measured after 15 min of submaximal exercise so that changes in Vo2max between 15 and 45 min of exercise could be assessed between the same points in time in which CV drift occurred.


RESULTS
Across both conditions, heart rate (HR) increased 5.4% and stroke volume (SV) decreased 11% from 15 to 45 min, but Vo2max was not significantly affected (7% reduction; 2.70 +/- 0.5 L min(-1) vs. 2.52 +/- 0.6 L min(-1)).


CONCLUSIONS
In a temperate environment, a small CV drift corresponds to a small, non-significant decrease in Vo2max, regardless of whether the exercise performed is cycling or walking.
Department of Kinesiology, University of Alabama, Tuscaloosa, AL 35487-0312, USA. jwingo@bamaed.ua.edu
Jonathan E
JE
Wingo
Laura J
LJ
Salaga
Mia K
MK
Newlin
Kirk J
KJ
Cureton
D000704:Analysis of Variance; D001642:Bicycling / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D010101:Oxygen Consumption / Q000502:physiology*; D013318:Stroke Volume / Q000502:physiology*; D013696:Temperature; D016138:Walking / Q000502:physiology*; D055815:Young Adult