Date of Award

1990

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

First Advisor

Steven G. Kamerling

Abstract

The purposes of this dissertation were to (1) determine running abilities of horses on the racetrack, (2) design treadmill standard exercise tests (SETs) to measure exercise variables that correlate with racetrack performance, and (3) assess the influence of training, competition, and ergogenic aids on performance. Run times of 25 Thoroughbreds were determined during solo and competitive track runs of 1200, 1600, and 2000 meters. Cardiac, respiratory, and hematologic variables were later measured during treadmill SETs. Variables were correlated with average run times. Heart rate scores, V$\sb{200}$, plasma lactate values, and maximal oxygen uptake correlated best with performance. Interval and conventional methods of training were compared to examine the effect of training method on performance. After 7.5 months of training, there was no difference in performance between groups. Interval training (IT) was more labor intensive, but it improved the durability of the horses. Interval training was used in a study of the treadmill as a training tool. Treadmill IT was the only conditioning received during a 20-week training period. There was a significant decrease in maximal heart rate during a sub-maximal SET. Cardiovascular fitness was attained solely with treadmill exercise. The effect of competition was examined by comparing race times for solo and competitive runs. No group ran faster during competition than alone. Run times for males were not affected by competition, while females were consistently slower during competitive runs. There were no differences in run times due to age. The slower competitive run times may have been due to the low quality of horses. The putative ergogenic effects of sodium bicarbonate and 12% fat supplementation were tested separately by comparing 1600-m run times following administration of the 2 ergogenic aids to a control run. There was no difference between control and bicarbonate run times even though blood pH and lactate were significantly increased following NaHCO$\sb3$ administration. Mean run time was significantly faster following fat supplementation when compared to the control diet. The improved run time may have been due to increased availability of blood glucose, better utilization of ketone bodies for fuel, and decreased ketosis in the fat-fed group which delayed the onset of fatigue.

Pages

350

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