ISSN:
1439-6327
Keywords:
$$\dot V$$ O2 half time response
;
O2 kinetics
;
$$\dot V$$ O2 kinetics
;
Exercise
;
Females
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary The oxygen consumption ( $$\dot V$$ O2) half time response was determined on eight female subjects during exercise using a nonlinear equation of the form $$\dot V$$ O2t= $$\dot V$$ O2ss (1−e−kt), where $$\dot V$$ O2t= $$\dot V$$ O2 at time t of exercise, $$\dot V$$ O2ss= $$\dot V$$ O2 at steady state, e = natural log, and k = constant of the curve, and a simple, linear equation of the form t=b( $$\dot V$$ O2t/ $$\dot V$$ O2ss)±a. The slope (b) and intercept (a) of the line, respectively, were determined for each work load and each subject using the $$\dot V$$ O2 measurements within the initial linear portion of the individual $$\dot V$$ O2 uptake curves. Two treadmill walks were used (¯X=38 and 65% $$\dot V$$ O2 max). For the lower work load, the ¯X±SD for the nonlinear and linear half time responses were 21.6±4.8 s and 21.6±4.9 S, respectively, and for the higher load 32.8±5.6 s and 32.6±3.6 s, respectively. No significant differences between linear and nonlinear means were found. The linear correlation between determinations was 0.88 (p〈0.001). The standard error of estimate was ±3.4 s with 95% confidence limits of ±7.2 s (±25.7% of the nonlinear half time mean). The $$\dot V$$ O2 half time response for the higher work load was significantly greater (p〈0.01) than for the lower load. Linear correlations of 0.84 and 0.76 (p〈0.01) between % $$\dot V$$ O2 max and linear and nonlinear determinations of the half time responses, respectively, were also found. We conclude that (1) the $$\dot V$$ O2 half time response at the onset of steady state exercise can be accurately determined on a group basis but not an individual basis from simple linear equations, and (2) the $$\dot V$$ O2 half time response is slower with increasing work loads.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00421766
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