Cardiopulmonary function during supramaximal exercise in hypoxia, normoxia and hyperoxia in Thoroughbred horses.
Abstract: Supramaximal exercise while inspiring different O gases may induce different responses in cardiopulmonary function at the same relative and/or absolute exercise intensity. The purpose of this study was to compare the effects of supramaximal exercise in hypoxia, normoxia and hyperoxia on cardiopulmonary function in Thoroughbred horses. Using a crossover design, five well-trained horses were made to run up a 6% grade on a treadmill at supramaximal speeds sustainable for approximately 110 sec (approximately 115% Omax) while breathing normoxic gas (NO, 21% O) or hypoxic gas (LO, 15.3% O) in random order. Horses also ran at the same speed, incline and run time as in NO while breathing hyperoxic gas (HO, 28.8% O) and as in LO while breathing normoxic gas (NO). Runs were on different days, and cardiopulmonary variables were analyzed with repeated-measures ANOVA and the Holm-Šidák method for pairwise comparisons. Supramaximal speeds differed significantly between NO and LO (14.0 ± 0.5 [SD] m/sec vs. 12.6 ± 0.5 m/sec), but run times to exhaustion did not (112 ± 17 sec vs. 103 ± 14 sec). The Omax in NO was higher than that in LO (165 ± 11 vs. 120 ± 15 ml (min× kg)), as was the arterial oxygen tension (66 ± 5 vs. 45 ± 2 Torr). Oxygen consumption was increased in HO and NO compared with the values in NO and LO, respectively. Supramaximal exercise in hypoxia induces more severe hypoxemia and decreases Omax compared with normoxia at the same relative intensity. Conversely, supramaximal exercise in hyperoxia alleviates hypoxemia and increases O compared with normoxia at the same absolute intensity.
©2020 The Japanese Society of Equine Science.
Publication Date: 2020-12-18 PubMed ID: 33376442PubMed Central: PMC7750644DOI: 10.1294/jes.31.67Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
This study investigates how different levels of inspired oxygen gases (hypoxia, normoxia, and hyperoxia) affect the cardiopulmonary function of Thoroughbred horses during intense exercise. The researchers found that the quantity of oxygen consumed varied under different conditions, indicating a change in the horse’s physiological response to exercise intensity.
Objective and Methodology
- The aim of the research was to understand how different oxygen gas levels influence the cardiopulmonary functionality in Thoroughbred horses during supramaximal exercise, a very high intensity workout. The three environments studied were hypoxia (low oxygen), normoxia (normal oxygen), and hyperoxia (high oxygen).
- The researchers utilized a crossover design in which five well-trained horses were made to run on a treadmill with a grade of 6% under specific conditions. They were first made to run up an incline in normoxic and hypoxic environments, after which their performance in a hyperoxic atmosphere was observed.
- To offer a comparative understanding, horses were also made to run at the same speed and incline while breathing normoxic gas like in LO conditions. Exercise times were kept identical in all experiments.
- Variables related to the animals’ cardiopulmonary responses, like oxygen uptake, speed, and time to exhaustion, were statistically analyzed using repeat-measures ANOVA and Holm-Šidák method for pairwise comparisons.
Findings and Interpretations
- Different exercises led to different levels of maximum oxygen consumption (Omax). Researchers found a significant variation in speeds when horses ran in NO and LO atmospheres, with the former yielding higher speeds.
- Importantly, running times to the point of exhaustion remained the same under different oxygen levels (approximately 110 seconds), suggesting that the duration of supramaximal exercise was unaffected by inspired gases strength.
- However, Omax values under NO conditions were greater than those in LO, indicating that the horses’ physiological responses to exercise varied with different levels of oxygen. Similar variations were observed in arterial oxygen tension.
- Furthermore, oxygen consumption increased significantly in HO and NO compared with values in NO and LO respectively. This showed that the horses’ bodies used more oxygen when they had more of it available.
- The findings show that engaging in extremely intense exercise in a hypoxic environment leads to severe hypoxemia (reduced oxygenation of the blood) and decreased Omax compared to normoxia at the same relative intensity. On the other hand, exercising intensively under hyperoxic conditions relieved hypoxemia and increased oxygen consumption relative to normoxia at the same absolute intensity.
- This research suggests that respiratory conditions have a significant influence on the cardiopulmonary responses in horses during vigorous workouts. More research is required for a comprehensive understanding of how different classes of animals respond to changes in oxygen availability during extreme workouts.
Cite This Article
APA
Ohmura H, Mukai K, Matsui A, Takahashi T, Jones JH.
(2020).
Cardiopulmonary function during supramaximal exercise in hypoxia, normoxia and hyperoxia in Thoroughbred horses.
J Equine Sci, 31(4), 67-73.
https://doi.org/10.1294/jes.31.67 Publication
Researcher Affiliations
- Sports Science Division, Equine Research Institute, Japan Racing Association, Tochigi 329-0412, Japan.
- Sports Science Division, Equine Research Institute, Japan Racing Association, Tochigi 329-0412, Japan.
- Sports Science Division, Equine Research Institute, Japan Racing Association, Tochigi 329-0412, Japan.
- Sports Science Division, Equine Research Institute, Japan Racing Association, Tochigi 329-0412, Japan.
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, CA 95616, U.S.A.
References
This article includes 23 references
- Birks EK, Jones JH, Berry JD. Plasma lactate kinetics in exercising horses. pp. 179–187. In: Equine Exercise Physiology 3 (Persson, S.G.B., Lindholm, A., and Jeffcott, L.B. eds.), ICEEP Publications, Uppsala.
- Erickson BK, Seaman J, Kubo K, Hiraga A, Kai M, Yamaya Y, Wagner PD. Hypoxic helium breathing does not reduce alveolar-arterial PO2 difference in the horse.. Respir Physiol 1995 Jun;100(3):253-60.
- Faiss R, Léger B, Vesin JM, Fournier PE, Eggel Y, Dériaz O, Millet GP. Significant molecular and systemic adaptations after repeated sprint training in hypoxia.. PLoS One 2013;8(2):e56522.
- Fedak MA, Rome L, Seeherman HJ. One-step N2-dilution technique for calibrating open-circuit VO2 measuring systems.. J Appl Physiol Respir Environ Exerc Physiol 1981 Sep;51(3):772-6.
- Hamlin MJ, Marshall HC, Hellemans J, Ainslie PN, Anglem N. Effect of intermittent hypoxic training on 20 km time trial and 30 s anaerobic performance.. Scand J Med Sci Sports 2010 Aug;20(4):651-61.
- Jones JH. Circulatory function during exercise: integration of convection and diffusion.. Adv Vet Sci Comp Med 1994;38A:217-51.
- Jones JH. Optimization of the mammalian respiratory system: symmorphosis versus single species adaptation.. Comp Biochem Physiol B Biochem Mol Biol 1998 May;120(1):125-38.
- Jones JH, Birks EK, Berry JD. Does oxygen transport limit VO2max in horses?. FASEB J 1988;3:430.
- Jones JH, Longworth KE, Lindholm A, Conley KE, Karas RH, Kayar SR, Taylor CR. Oxygen transport during exercise in large mammals. I. Adaptive variation in oxygen demand.. J Appl Physiol (1985) 1989 Aug;67(2):862-70.
- Kasai N, Mizuno S, Ishimoto S, Sakamoto E, Maruta M, Goto K. Effect of training in hypoxia on repeated sprint performance in female athletes.. Springerplus 2015;4:310.
- Kon M, Nakagaki K, Ebi Y, Nishiyama T, Russell AP. Hormonal and metabolic responses to repeated cycling sprints under different hypoxic conditions.. Growth Horm IGF Res 2015 Jun;25(3):121-6.
- Nagahisa H, Mukai K, Ohmura H, Takahashi T, Miyata H. Effect of High-Intensity Training in Normobaric Hypoxia on Thoroughbred Skeletal Muscle.. Oxid Med Cell Longev 2016;2016:1535367.
- Ohmura H, Hiraga A, Jones JH. Method for quantifying net anaerobic power in exercising horses.. Equine Vet J Suppl 2006 Aug;(36):370-3.
- Ohmura H, Hiraga A, Jones JH. Exercise-induced hypoxemia and anaerobic capacity in thoroughbred horses. J. Phys. Fit. Sports Med. 2013;2:163–168.
- Ohmura H, Matsui A, Hada T, Jones JH. Physiological responses of young thoroughbred horses to intermittent high-intensity treadmill training.. Acta Vet Scand 2013 Aug 17;55(1):59.
- Ohmura H, Mukai K, Takahashi T, Matsui A, Hiraga A, Jones JH. Comparison of net anaerobic energy utilisation estimated by plasma lactate accumulation rate and accumulated oxygen deficit in Thoroughbred horses.. Equine Vet J Suppl 2010 Nov;(38):62-9.
- Ohmura H, Mukai K, Takahashi Y, Takahashi T, Jones JH. Hypoxic training increases maximal oxygen consumption in Thoroughbred horses well-trained in normoxia.. J Equine Sci 2017;28(2):41-45.
- Okabe K, Mukai K, Ohmura H, Takahashi T, Miyata H. Effect of acute high-intensity exercise in normobaric hypoxia on Thoroughbred skeletal muscle.. J Sports Med Phys Fitness 2017 May;57(5):711-719.
- Richardson AJ, Relf RL, Saunders A, Gibson OR. Similar Inflammatory Responses following Sprint Interval Training Performed in Hypoxia and Normoxia.. Front Physiol 2016;7:332.
- Siggaard-Andersen O, Wimberley PD, Fogh-Andersen N, Gøthgen IH. Measured and derived quantities with modern ph and blood gas equipment: Calculation algorithms with 54 equations. Scand. J. Clin. Lab. Invest. 1988;48:7–15.
- Ulrich S, Hasler ED, Müller-Mottet S, Keusch S, Furian M, Latshang TD, Schneider S, Saxer S, Bloch KE. Mechanisms of Improved Exercise Performance under Hyperoxia.. Respiration 2017;93(2):90-98.
- Wagner PD, Erickson BK, Seaman J, Kubo K, Hiraga A, Kai M, Yamaya Y. Effects of altered FIO2 on maximum VO2 in the horse.. Respir Physiol 1996 Aug;105(1-2):123-34.
- Wagner PD, Gillespie JR, Landgren GL, Fedde MR, Jones BW, DeBowes RM, Pieschl RL, Erickson HH. Mechanism of exercise-induced hypoxemia in horses.. J Appl Physiol (1985) 1989 Mar;66(3):1227-33.
Citations
This article has been cited 5 times.- Davie A, Beavers R, Hargitaiová K, Denham J. The Emerging Role of Hypoxic Training for the Equine Athlete. Animals (Basel) 2023 Sep 3;13(17).
- Mukai K, Kitaoka Y, Takahashi Y, Takahashi T, Takahashi K, Ohmura H. Moderate-intensity training in hypoxia improves exercise performance and glycolytic capacity of skeletal muscle in horses. Physiol Rep 2021 Dec;9(23):e15145.
- Ohmura H, Mukai K, Takahashi Y, Takahashi T. Metabolomic analysis of skeletal muscle before and after strenuous exercise to fatigue. Sci Rep 2021 May 27;11(1):11261.
- Mukai K, Ohmura H, Takahashi Y, Kitaoka Y, Takahashi T. Four weeks of high-intensity training in moderate, but not mild hypoxia improves performance and running economy more than normoxic training in horses. Physiol Rep 2021 Feb;9(4):e14760.
- Takahashi K, Mukai K, Takahashi Y, Ebisuda Y, Sugiyama F, Hatta H, Kitaoka Y. Effects of hypoxia and hyperoxia on exercise-induced metabolomic and transcriptomic profiles in equine skeletal muscle. J Exp Biol 2025 Dec 15;228(24).
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
