Skeletal muscle adaptations to prolonged training, overtraining and detraining in horses.
Abstract: Thirteen standard-bred horses were trained intensively for 34 weeks and detrained for 6 weeks to study skeletal muscle adaptations to prolonged training, overtraining and detraining. Training included endurance (phase 1, 7 weeks), high-intensity (phase 2, 9 weeks) and overload training (OLT) (phase 3, 18 weeks). During phase 3, horses were divided into two groups, OLT and control (C), with OLT horses performing greater intensities and durations of exercise than C horses. Overtraining was evident in OLT horses after week 31 and was defined as a significant reduction in treadmill run time in response to a standardised exercise test (P<0.05). Relationships between peripheral (skeletal muscle) and whole body (maximum O2 uptake, V.O2, max, treadmill run time) adaptations to training were determined. Prolonged training resulted in significant adaptations in morphological characteristics of skeletal muscle but the adaptations were limited and largely completed by 16 weeks of training. Fibre area increased in all fibres while the number of capillaries per fibre increased and the diffusional index (area per capillary) decreased. Mitochondrial volume density continued to increase throughout 34 weeks of training and paralleled increases in V.O2,max and treadmill run time. Significant correlations were noted between mitochondrial volume and V.O2,max (R=0.71), run time and V.O2,max (R=0.83) and mitochondrial volume and run time (R=0.57). We conclude that many of adaptive responses of muscle fibre area and capillarity occur in the initial training period but that markers of oxidative capacity of muscle indicate progressive increases in aerobic capacity with increases in training load. The lack of differences between C and OLT groups indicated that there may be an upper limit to the ability of training stimulus to evoke skeletal muscle adaptive responses. There was no effect of overtraining or detraining on any of the adaptive responses measured.
Publication Date: 1998-06-30 PubMed ID: 9644221DOI: 10.1007/s004240050648Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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This research paper investigates the adaptation of skeletal muscle in horses to long-term intensive training, overtraining, and then detraining. It suggests that whilst muscle fibre adaptation occurs mostly in the initial training period, continuous training over time led to increases in aerobic capacity.
Study Design and Methods
- The study involved thirteen standard-bred horses who were put through a rigorous training regimen for 34 weeks followed by 6 weeks of detraining.
- The training period comprised of three phases: endurance (7 weeks), high-intensity (9 weeks), and overload training (18 weeks).
- During the overload training phase, the horses were split into two groups: the overload training (OLT) group and the control group. Horses in the OLT group performed more intense and longer exercise sessions than those in the control group.
Findings
- By the 31st week, the instances of overtraining were prevalent among the horses in the OLT group, as evidenced by a reduction in treadmill run time during standardised exercise tests.
- The researchers observed significant changes in the morphological characteristics of the horses’ skeletal muscles, with the adaptations largely completed by the 16th week of training.
- There was an increase in all fibre areas and the number of capillaries per fibre, while the diffusional index (area per capillary) decreased.
- The volume density of mitochondria in the muscles continued to rise throughout the training period. This rise paralleled increases in the animals’ maximum oxygen uptake (VO2 Max) and treadmill run time.
- Significant correlations were found between mitochondrial volume and both VO2 Max and run time.
Conclusions
- The bulk of muscle fibre area and capillarity adaptations occur during the initial stages of training.
- Indicators of the muscle’s oxidative capacity suggested a gradual increase in aerobic capacity with the increase in training load.
- There was no significant difference between the OLT and control groups’ results, suggesting there might be an upper limit to the adaptive response of skeletal muscle to training stimulus.
- No effect of overtraining or detraining on the adaptive responses of the skeletal muscles was observed.
Cite This Article
APA
Tyler CM, Golland LC, Evans DL, Hodgson DR, Rose RJ.
(1998).
Skeletal muscle adaptations to prolonged training, overtraining and detraining in horses.
Pflugers Arch, 436(3), 391-397.
https://doi.org/10.1007/s004240050648 Publication
Researcher Affiliations
- Equine Performance Laboratory, The University of Sydney, Rural Veterinary Centre, PMB 4, Werombi Rd., Camden, NSW 2570 Australia.
MeSH Terms
- Adaptation, Physiological / physiology
- Animals
- Horses / physiology
- Male
- Mitochondria, Muscle / ultrastructure
- Muscle Fibers, Fast-Twitch / ultrastructure
- Muscle Fibers, Slow-Twitch / ultrastructure
- Muscle, Skeletal / physiology
- Muscle, Skeletal / ultrastructure
- Oxygen Consumption
- Physical Conditioning, Animal
- Time Factors
Citations
This article has been cited 13 times.- de Meeûs d'Argenteuil C, Boshuizen B, Vidal Moreno de Vega C, Leybaert L, de Maré L, Goethals K, De Spiegelaere W, Oosterlinck M, Delesalle C. Comparison of Shifts in Skeletal Muscle Plasticity Parameters in Horses in Three Different Muscles, in Answer to 8 Weeks of Harness Training. Front Vet Sci 2021;8:718866.
- de Meeûs d'Argenteuil C, Boshuizen B, Oosterlinck M, van de Winkel D, De Spiegelaere W, de Bruijn CM, Goethals K, Vanderperren K, Delesalle CJG. Flexibility of equine bioenergetics and muscle plasticity in response to different types of training: An integrative approach, questioning existing paradigms. PLoS One 2021;16(4):e0249922.
- Katz LM, Stallard J, Holtby A, Hill EW, Allen K, Sweeney J. Inspiratory muscle training in young, race-fit Thoroughbred racehorses during a period of detraining. PLoS One 2020;15(4):e0225559.
- Klein DJ, McKeever KH, Mirek ET, Anthony TG. Metabolomic Response of Equine Skeletal Muscle to Acute Fatiguing Exercise and Training. Front Physiol 2020;11:110.
- Farries G, Bryan K, McGivney CL, McGettigan PA, Gough KF, Browne JA, MacHugh DE, Katz LM, Hill EW. Expression Quantitative Trait Loci in Equine Skeletal Muscle Reveals Heritable Variation in Metabolism and the Training Responsive Transcriptome. Front Genet 2019;10:1215.
- White SH, Warren LK, Li C, Wohlgemuth SE. Submaximal exercise training improves mitochondrial efficiency in the gluteus medius but not in the triceps brachii of young equine athletes. Sci Rep 2017 Oct 30;7(1):14389.
- Robbins PJ, Ramos MT, Zanghi BM, Otto CM. Environmental and Physiological Factors Associated With Stamina in Dogs Exercising in High Ambient Temperatures. Front Vet Sci 2017;4:144.
- Bryan K, McGivney BA, Farries G, McGettigan PA, McGivney CL, Gough KF, MacHugh DE, Katz LM, Hill EW. Equine skeletal muscle adaptations to exercise and training: evidence of differential regulation of autophagosomal and mitochondrial components. BMC Genomics 2017 Aug 9;18(1):595.
- Chanda M, Srikuea R, Cherdchutam W, Chairoungdua A, Piyachaturawat P. Modulating effects of exercise training regimen on skeletal muscle properties in female polo ponies. BMC Vet Res 2016 Nov 4;12(1):245.
- Hyytiäinen HK, Mykkänen AK, Hielm-Björkman AK, Stubbs NC, McGowan CM. Muscle fibre type distribution of the thoracolumbar and hindlimb regions of horses: relating fibre type and functional role. Acta Vet Scand 2014 Jan 27;56(1):8.
- Votion DM, Gnaiger E, Lemieux H, Mouithys-Mickalad A, Serteyn D. Physical fitness and mitochondrial respiratory capacity in horse skeletal muscle. PLoS One 2012;7(4):e34890.
- de Graaf-Roelfsema E, Veldhuis PP, Keizer HA, van Ginneken MM, van Dam KG, Johnson ML, Barneveld A, Menheere PP, van Breda E, Wijnberg ID, van der Kolk JH. Overtrained horses alter their resting pulsatile growth hormone secretion. Am J Physiol Regul Integr Comp Physiol 2009 Aug;297(2):R403-11.
- Vidal Moreno de Vega C, de Meeûs d'Argenteuil C, Boshuizen B, De Mare L, Gansemans Y, Van Nieuwerburgh F, Deforce D, Goethals K, De Spiegelaere W, Leybaert L, Verdegaal EJMM, Delesalle C. Baselining physiological parameters in three muscles across three equine breeds. What can we learn from the horse?. Front Physiol 2024;15:1291151.
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