Effect of a 14-Day Period of Heat Acclimation on Horses Using Heated Indoor Arenas in Preparation for Tokyo Olympic Games

Overview

Journal Animals (Basel)

Date 2024 Feb 24

PMID 38396514

Authors

Carolien Munsters

Esther Siegers

Marianne Sloet van Oldruitenborgh-Oosterbaan

Affiliations

Soon will be listed here.

Abstract

To optimise the performance and welfare of horses during equestrian competitions in hot climates, it is advised to acclimate them to the heat. The effects of training in a heated indoor arena were studied. Four Olympic horses (13.3 ± 2.2 years; three eventers, one para-dressage horse) were trained for 14 consecutive days in a heated indoor arena (32 ± 1 °C; 50-60% humidity) following their normal training schedule in preparation for the Tokyo Olympic games. Standardised exercise tests (SETs) were performed on Day 1 and Day 14, measuring heart rate (HR; bpm), plasma lactate concentration (LA; mmol/L), deep rectal temperature (T; °C), sweat loss (SL; L), and sweat composition (K, Cl and Na concentration). The data were analysed using linear mixed models. The T and HR were significantly decreased after acclimation (estimate: -0.106, 95% CI -0.134, -0.078; estimate: -4.067, 95% CI -7.535, -0.598, respectively). Furthermore, for all the horses, the time taken to reach their peak T and heat storage increased, while their LA concentrations decreased. The SL, Cl, and Na concentrations decreased in three out of the four horses. Conclusions: Fourteen days of normal training in a heated indoor arena resulted in a reduction in cardiovascular and thermal strain. This is advantageous because it shows that elite sport horses can be acclimated while training as usual for a championship.

Citing Articles

Cardiovascular Fitness and Stride Acceleration in Race-Pace Workouts for the Prediction of Performance in Thoroughbreds.

Schrurs C, Dubois G, van Erck-Westergren E, Gardner D Animals (Basel). 2024; 14(9).

PMID: 38731345 PMC: 11083884. DOI: 10.3390/ani14091342.

References

Kohn C, Hinchcliff K, McCutcheon L, Geor R, Foreman J, Allen A . Physiological responses of horses competing at a modified 1 star 3-day-event. Equine Vet J Suppl. 1995; (20):97-104. DOI: 10.1111/j.2042-3306.1995.tb05014.x. View

Marlin D, Harris P, Schroter R, Harris R, Roberts C, Scott C . Physiological, metabolic and biochemical responses of horses competing in the speed and endurance phase of a CCI*****3-day-event. Equine Vet J Suppl. 1995; (20):37-46. DOI: 10.1111/j.2042-3306.1995.tb05006.x. View

Lorenzo S, Halliwill J, Sawka M, Minson C . Heat acclimation improves exercise performance. J Appl Physiol (1985). 2010; 109(4):1140-7. PMC: 2963322. DOI: 10.1152/japplphysiol.00495.2010. View

Periard J, Travers G, Racinais S, Sawka M . Cardiovascular adaptations supporting human exercise-heat acclimation. Auton Neurosci. 2016; 196:52-62. DOI: 10.1016/j.autneu.2016.02.002. View

Marlin D . Heat, humidity and horse welfare in the Olympic Games: learning from history. Vet J. 2009; 182(3):373-4. DOI: 10.1016/j.tvjl.2009.08.025. View

Art T, Votion D, Lekeux P . Physiological measurements in horses after strenuous exercise in hot, humid conditions. Equine Vet J Suppl. 1995; (20):120-4. DOI: 10.1111/j.2042-3306.1995.tb05017.x. View

Kohn C, Hinchcliff K, McKeever K . Evaluation of washing with cold water to facilitate heat dissipation in horses exercised in hot, humid conditions. Am J Vet Res. 1999; 60(3):299-305. View

Marlin D, Scott C, Schroter R, Mills P, Harris R, Harris P . Physiological responses in nonheat acclimated horses performing treadmill exercise in cool (20 degrees C/40% RH), hot dry (30 degrees C/40% RH) and hot humid (30 degrees C/80% RH) conditions. Equine Vet J Suppl. 1996; (22):70-84. View

Lindinger M, Geor R, Ecker G, McCutcheon L . Plasma volume and ions during exercise in cool, dry; hot, dry; and hot, humid conditions. Equine Vet J Suppl. 1995; (20):133-9. DOI: 10.1111/j.2042-3306.1995.tb05019.x. View

10.

McCutcheon L, Geor R, Ecker G, Lindinger M . Equine sweating responses to submaximal exercise during 21 days of heat acclimation. J Appl Physiol (1985). 1999; 87(5):1843-51. DOI: 10.1152/jappl.1999.87.5.1843. View

11.

Lindinger M, McCutcheon L, Ecker G, Geor R . Heat acclimation improves regulation of plasma volume and plasma Na(+) content during exercise in horses. J Appl Physiol (1985). 2000; 88(3):1006-13. DOI: 10.1152/jappl.2000.88.3.1006. View

12.

Alkemade P, Gerrett N, Eijsvogels T, Daanen H . Individual characteristics associated with the magnitude of heat acclimation adaptations. Eur J Appl Physiol. 2021; 121(6):1593-1606. PMC: 8144163. DOI: 10.1007/s00421-021-04626-3. View

13.

Corbett J, Rendell R, Massey H, Costello J, Tipton M . Inter-individual variation in the adaptive response to heat acclimation. J Therm Biol. 2018; 74:29-36. DOI: 10.1016/j.jtherbio.2018.03.002. View

14.

Marlin D, Scott C, Schroter R, Harris R, Harris P, Roberts C . Physiological responses of horses to a treadmill simulated speed and endurance test in high heat and humidity before and after humid heat acclimation. Equine Vet J. 1999; 31(1):31-42. DOI: 10.1111/j.2042-3306.1999.tb03788.x. View

15.

Geor R, McCutcheon L, Ecker G, Lindinger M . Thermal and cardiorespiratory responses of horses to submaximal exercise under hot and humid conditions. Equine Vet J Suppl. 1995; (20):125-32. DOI: 10.1111/j.2042-3306.1995.tb05018.x. View

16.

Marlin D, Schroter R, White S, Maykuth P, Matthesen G, Mills P . Recovery from transport and acclimatisation of competition horses in a hot humid environment. Equine Vet J. 2001; 33(4):371-9. DOI: 10.2746/042516401776249507. View

17.

Hodgson D, McCutcheon L, Byrd S, BROWN W, Bayly W, Brengelmann G . Dissipation of metabolic heat in the horse during exercise. J Appl Physiol (1985). 1993; 74(3):1161-70. DOI: 10.1152/jappl.1993.74.3.1161. View

18.

Douglas J, Owers R, Campbell M . Social Licence to Operate: What Can Equestrian Sports Learn from Other Industries?. Animals (Basel). 2022; 12(15). PMC: 9367437. DOI: 10.3390/ani12151987. View

19.

Jeffcott L, Kohn C . Contributions of equine exercise physiology research to the success of the 1996 Equestrian Olympic Games: a review. Equine Vet J Suppl. 2000; (30):347-55. DOI: 10.1111/j.2042-3306.1999.tb05247.x. View

20.

Hulten C, Tulamo R, Suominen M, Burvall K, Marhaug G, Forsberg M . A non-competitive chemiluminescence enzyme immunoassay for the equine acute phase protein serum amyloid A (SAA) -- a clinically useful inflammatory marker in the horse. Vet Immunol Immunopathol. 1999; 68(2-4):267-81. DOI: 10.1016/s0165-2427(99)00027-6. View