Effects of warm-up intensity on kinetics of oxygen consumption and carbon dioxide production during high-intensity exercise in horses.
OBJECTIVE
To compare effects of low and high intensity warm-up exercise on oxygen consumption (VO2) and carbon dioxide production (VCO2) in horses.


METHODS
6 moderately conditioned adult Standard-breds.


METHODS
Horses ran for 2 minutes at 115% of maximum oxygen consumption (VO2max), 5 minutes after each of the following periods: no warm-up (NoWU); 10 minutes at 50% of VO2max (LoWU); or 7 minutes at 50% VO2max followed by 45-second intervals at 80, 90, and 100% VO2max (HiWU). Oxygen consumption and VCO2 were measured during exercise, and kinetics of VO2 and VCO2 were calculated. Accumulated O2 deficit was also calculated.


RESULTS
For both warm-up trials, the time constant for the rapid exponential increase in VO2 was 30% lower than for NoWU. Similarly, the rate of increase in VCO2 was 23% faster in LoWU and HiWU than in NoWU. Peak values for VO2 achieved during the high-speed test were not significantly different among trials (LoWU, 150.2 +/- 3.2 ml/kg/min; HiWU, 151.2 +/- 4.2 ml/kg/min; NoWU, 145.1 +/- 4.1 ml/kg/min). However, accumulated O2 deficit (ml of O2 equivalents/kg) was significantly lower during LoWU (65.3 +/- 5.1) and HiWU (63.4 +/- 3.9) than during NoWU (82.1 +/- 7.3).


CONCLUSIONS
Both the low- and high-intensity warm-up, completed 5 minutes before the start of high-intensity exercise, accelerated the kinetics of VO2 and VCO2 and decreased accumulated O2 deficit during 2 minutes of intense exertion in horses that were moderately conditioned.
Geor
R J
RJ
Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus 43210, USA.
McCutcheon
L J
LJ
Hinchcliff
K W
KW
D000818:Animals; D001831:Body Temperature; D002151:Calorimetry / Q000662:veterinary; D002245:Carbon Dioxide / Q000378:metabolism*; D018592:Cross-Over Studies; D005260:Female; D006736:Horses / Q000502:physiology*; D007700:Kinetics; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D011659:Pulmonary Gas Exchange; D011897:Random Allocation; D012044:Regression Analysis
D002245:Carbon Dioxide