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Hyperbolic relationship between time‐to‐fatigue and workload
Author(s) -
LAUDERDALE M. A.,
HINCHCLIFF K. W.
Publication year - 1999
Publication title -
equine veterinary journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.82
H-Index - 87
eISSN - 2042-3306
pISSN - 0425-1644
DOI - 10.1111/j.2042-3306.1999.tb05289.x
Subject(s) - anaerobic exercise , workload , hyperbolic function , mathematics , linear regression , power (physics) , work (physics) , exponential function , statistics , medicine , physical therapy , mathematical analysis , computer science , physics , thermodynamics , operating system
Summary The power:time‐to‐fatigue relationship for high‐intensity exercise in man is useful in determining anaerobic work capacity. The purpose of this study was to determine the nature of this relationship in horses. Eight Standardbred horses performed 5 or 6 run‐to‐fatigue trials on a treadmill. Exercise intensities were chosen to induce fatigue in 30 to 240 s. The order of trials was randomised for each horse, but balanced overall for the first 4 trials. The data for power (independent variable) and time‐to‐fatigue (dependent variable) were tested for goodness of fit to hyperbolic, linear and exponential equations by nonlinear regression. The best fit to the data was obtained using the hyperbolic relationship t = W'/(P‐ Ø PA ) where t is the time to fatigue, W' is the anaerobic work capacity, P is the power and Ø PA is the critical power value. The values for W' and Ø PA were 47,000 ± 500 J and 2490 ± 150 watts, respectively. We conclude that the power:time‐to‐fatigue relationship of horses is hyperbolic and that this relationship may be useful in assessing anaerobic capacity of horses.