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Indices of exercise capacity in horses presented for poor racing performance
Author(s) -
ROSE R. J.,
KING C. M.,
EVANS D. L.,
TYLER C. M.,
HODGSON D. R.
Publication year - 1995
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.2042-3306.1995.tb04964.x
Subject(s) - treadmill , heart rate , horse , zoology , stride , blood lactate , breed , vo2 max , medicine , cardiology , chemistry , blood pressure , biology , physical medicine and rehabilitation , paleontology
Summary We examined 106 Thoroughbred (TB) and 51 Standardbred (SB) racehorses that were presented because of poor performance. All horses were in training and had raced within 2 weeks of presentation. Horses were acclimatised (2–4 runs) and tested on a treadmill set at a 10% slope. The exercise test consisted of 3 min at 4 m/s, 2 min at 6 m/s, then 1 min steps at 8, 10, 11, 12 and 13 m/s or until the horse could not maintain pace with the treadmill. At the end of each speed, arterial blood and expired gas samples were collected and heart rate recorded. Measurements during the test included: arterial blood gas tensions, plasma lactate concentration [LA], V̇O 2 , V̇CO 2 , O 2 pulse (V̇O 2 /HR), heart rate, maximum stride length (SLmax), post exercise haematocrit (PCV PE ), total red cell volume (CV) and total run time. The TB ran longer than SB (522 vs. 477 s) and had higher values for CV, PCV PE , V̇O 2max , V̇O 2 ‐200, maximum O 2 pulse, V 200 , V HRmax , post exercise [LA] ([LA PE ]) and SLmax. There were no breed differences for V LA4 and PaO 2 at 10 m/s. In the TB, significant correlations (Spearman's rank order) (P<0.01) were found for treadmill run time with: PCV PE , V̇O 2max , V̇O 2– 200, peak O 2 pulse, PaO 2 at 10 m/s, PaCO 2 at 10 m/s, V 200 , V LA4 , [LA PE ], V HRmax , maximum blood temperature and SLmax. In the SB significant but lower correlations (P<0.05) were found for treadmill run time with: PCV PE , V̇O 2max , V 200 , V LA4 , [LA PE ], V HRmax , maximum blood temperature and SLmax. While these results may not be applicable to normal racehorses, the indices which correlated best with treadmill run time were generally those indicating a high capacity for oxygen transport.