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Blood gas changes during incremental and sprint exercise
Author(s) -
CHRISTLEY R. M.,
EVANS D. L.,
HODGSON D. R.,
ROSE R. J.
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.tb05182.x
Subject(s) - sprint , incremental exercise , treadmill , heart rate , medicine , blood lactate , cardiology , anaerobic exercise , physical therapy , blood pressure
Summary We investigated and compared arterial blood gas and ventilatory changes during rapid acceleration sprint and during incremental treadmill exercise. Seven clinically normal racehorses completed standardised incremental exercise tests and rapid acceleration tests at speeds calculated to elicit 115% V̇ o 2max . Arterial oxygen tension decreased (P<.001) between 15 s (mean ± s.d. 103.8 ± 14.3 mmHg) and 30 s (85.0 ± 7.7 mmHg) after the onset of rapid acceleration exercise, but did not change significantly during the remainder of the sprint. This was accompanied by an increase in Pa co 2 of 5.9 mmHg (P<.05). Despite reductions in Sa o 2 during exercise, Ca o 2 did not change due to increases in haemoglobin concentration. Heart rate increased rapidly (P<.001) during the first 15 s of exercise and thereafter remained constant. The mean maximum speed during the incremental test (11.4 ± 0.5m/s) was not significantly different to the speed calculated to elicit 115% V̇ o 2max during the sprint test (12.2 ± 0.8 m/s). The mean peak HR and Hb during the sprint test were significantly less than during the incremental test. However, there were no significant differences in the maximum or minimum values achieved for other variables. We conclude that rapid acceleration exercise is accompanied by rapid changes in blood gas variables, reaching steady state within 45 s. Blood gas responses during the simpler incremental test describe maximal changes during high‐intensity sprint exercise.