Changes in maximum oxygen uptake during prolonged training,
overtraining and detraining in horses.
Tyler, Catherine M., Lorraine C. Golland, David L. Evans, David R.
Hodgson, and Reuben J. Rose.
Department of Animal Health, Department of Animal Science, The
University of Sydney, Rural Veterinary Centre, Camden NSW 2570
Australia
APStracts 3:0357A, 1996.
Thirteen Standardbred horses were trained as follows: phase 1
(endurance training - 7 weeks), phase 2 (high intensity training - 9
weeks), phase 3 (overload training - 18 weeks) and phase 4
(detraining - 12 weeks). In phase 3 the horses were divided into 2
groups: overload training (OLT) and control (C). The OLT group
exercised at greater intensities, frequencies and durations than
group C. Overtraining occurred after 31 weeks training and was
defined as a significant decrease in treadmill run time in response
to a standardised exercise test. In the OLT group there was a
significant decrease in body weight (p<0.05). From pre-training
values of 117 +/- 2 ml.kg-1.min-1 (mean +/- sem), VO2max increased by
15% at the end of phase 1 and when signs of overtraining were first
seen in the OLT group, VO2max was 29% higher (151 +/- 2 ml.kg-1.min-1
in both C and OLT groups) than pre-training values. There was no
significant reduction in VO2max until after 6 weeks detraining when
VO2max was 137 +/- 2 ml.kg-1.min-1 . By 12 weeks detraining, mean
VO2max was 134 +/- 2 ml.kg-1.min-1, still 15% above pretraining
values. When overtraining developed, VO2max was not different between
C and OLT groups, but maximal values for VCO2 (147 vs 159 ml.kg
-1.min-1 ) and R (1.04 vs 1.11) were lower in the OLT group.
Overtraining was not associated with a decrease in VO2max and, after
prolonged training, decreases in VO2max occurred slowly during
detraining.
Received 11 December 1995; accepted in final form 10 July 1996.
APS Manuscript Number A1286-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 4 August 1996