title: Comparison of aerobic capacity between racing standardbred horses.
abstract: A standardized treadmill test was used to compare metabolic and ventilatory measurements between 10 standardbred racehorses. The horses were divided into two groups: group A (n = 5) had mean racing speeds of 4.4 s faster than group B (n = 5) over a 1-mi. distance. Each horse was fitted with a venous catheter and connected to a valved gas-collection system. The exercise test consisted of 1-min incremental workloads ranging from 4.0 to 12.0 m/s at a treadmill incline of 3 degrees. Group A had significantly higher (P < 0.05) measurements of maximal O2 consumption (VO2max), O2 pulse, and tidal volume. Venous lactate concentration and respiratory exchange ratio measured at VO2max were also significantly higher (P < 0.05) in group A. Similar treadmill velocities were required to achieve a respiratory exchange ratio of > 1 and venous blood lactate concentration of > 4 mmol/l; however, group A was able to complete a significantly higher (P < 0.01) number of workloads before fatigue. The high aerobic and anaerobic capacity of group A horses may be a major contributor to a faster racing performance.
authors.affiliation: Department of Clinical Studies, University of Guelph, Ontario, Canada.
authors.forename: G M
authors.initials: GM
authors.lastname: Gauvreau
authors.forename: H
authors.initials: H
authors.lastname: Staempfli
authors.forename: L J
authors.initials: LJ
authors.lastname: McCutcheon
authors.forename: S S
authors.initials: SS
authors.lastname: Young
authors.forename: W N
authors.initials: WN
authors.lastname: McDonell
mesh_terms: D000818:Animals; D006736:Horses / Q000502:physiology*; D010101:Oxygen Consumption / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology*; D012119:Respiration / Q000502:physiology*; D012129:Respiratory Function Tests