Exercise training increases oxidative capacity and attenuates exercise-induced ultrastructural damage in skeletal muscle of aged horses
- 1 January 2005
- journal article
- Published by American Physiological Society in Journal of Applied Physiology
- Vol. 98 (1), 334-342
- https://doi.org/10.1152/japplphysiol.00172.2003
Abstract
Exercise training improves functional capacity in aged individuals. Whether such training reduces the severity of exercise-induced muscle damage is unknown. The purpose of the present study was to determine the effect of 10 wk of treadmill exercise training on skeletal muscle oxidative capacity and exercise-induced ultrastructural damage in six aged female Quarter horses (>23 yr of age). The magnitude of ultrastructural muscle damage induced by an incremental exercise test before and after training was determined by electron microscopic examination of samples of triceps, semimembranosus, and masseter (control) muscles. Maximal aerobic capacity increased 22% after 10 wk of exercise training. The percentage of type IIa myosin heavy chain increased in semimembranosus muscle, whereas the percentage of type IIx myosin heavy chain decreased in triceps muscle. After training, triceps muscle showed significant increases in activities of both citrate synthase and 3-hydroxyacyl-CoA-dehydrogenase. Attenuation of exercise-induced ultrastructural muscle damage occurred in the semimembranosus muscle at both the same absolute and the same relative workloads after the 10-wk conditioning period. We conclude that aged horses adapt readily to intense aerobic exercise training with improvements in endurance, whole body aerobic capacity, and muscle oxidative capacity, and heightened resistance to exercise-induced ultrastructural muscle cell damage. However, adaptations may be muscle-group specific.Keywords
This publication has 31 references indexed in Scilit:
- Ageing, muscle properties and maximal O2 uptake rate in humansThe Journal of Physiology, 2000
- A Comparison of the Ultrastructure and Metabolic Response of the Skeletal Muscle of Horses Performing Intense Treadmill Exercise at 20 and 35°CJournal of Veterinary Medicine Series A, 1999
- Skeletal myosin heavy chain composition and carriage trainingEquine Veterinary Journal, 1999
- Heritability of percentage of fast myosin heavy chains in skeletal muscles and relationship with performanceEquine Veterinary Journal, 1999
- Effects of Strength Training on Muscle Hypertrophy and Muscle Cell Disruption in Older MenInternational Journal of Sports Medicine, 1995
- Satellite cell activation after muscle damage in young and adult ratsThe Anatomical Record, 1995
- Muscle characteristics in Thoroughbreds of different ages and sexesEquine Veterinary Journal, 1991
- Selective damage of fast glycolytic muscle fibres with eccentric contraction of the rabbit tibialis anteriorActa Physiologica Scandinavica, 1988
- Oxidative capacity of skeletal muscle fibres in racehorses: histochemical versus biochemical analysisEquine Veterinary Journal, 1988
- Histochemical properties of muscle fibre types and enzyme activities in skeletal muscles of Standardbred trotters of different agesEquine Veterinary Journal, 1980