A Preliminary Study Exploring the Relationship Between Exercise Regimes and Sleep-Related Behavior in Stabled Horses
DOI:
https://doi.org/10.64292/ijes.207Keywords:
Equine, rest-activity cycle, welfare, workloads, circadianAbstract
Exercise is a recognized time cue for circadian rhythms, influencing sleep architecture and quality across diverse human populations. While its timing and intensity affect sleep outcomes in humans, little is known about how exercise impacts sleep in horses, particularly those with early morning or late evening workloads, as is common in working or competition horses. This study sought to explore this relationship in stabled horses experiencing changes to their workload patterns. Five geldings housed at Hartpury Equestrian Centre were observed across three exercise phases (normal, increased, and return to normal) using an ABA design. Sleep-related behaviors were recorded overnight using closed-circuit television (CCTV) equipment and analyzed using a validated ethogram with continuous focal sampling. Inter-observer reliability tests confirmed consistent behavioral scoring, and data were analyzed using nonparametric statistics to compare behavioral time budgets, as well as postures, across phases. Horses spent the majority of their time awake, followed by sleep and rest, across all exercise phases. Increased exercise led to significantly longer sleep bouts (Phase B: 10.79 min vs. Phase A: 5.33 min, P < 0.05) and more frequent rest episodes. Sleep postures also changed, specifically sternal recumbency, where Phases B and C were statistically different from Phase A. Results also indicated a residual effect of exercise on sleep and rest patterns, with sleep patterns remaining altered even after a return to normal exercise (Phase C: 8.98 min), indicating prolonged recovery effects. Findings demonstrate that exercise-induced changes in sleep architecture persist beyond the intervention period, highlighting the importance of recovery planning in equine management and supporting the need for larger-scale studies to disentangle the relationship between sleep and exercise to optimize equine performance and well-being.
References
Merrow M, Dragovic Z, Tan Y, Meyer G, Sveric K, Mason M, et al. Combining theoretical and experimental approaches to understand the circadian clock. Chronobiology International 2003;20:559–75. https://doi.org/10.1081/cbi-120023678.
Hughes ATL. Locomotor exercise and circadian rhythms in mammals. Current Opinion in Physiology 2018;5:51–7. https://doi.org/10.1016/j.cophys.2018.07.001.
Uchida S, Shioda K, Morita Y, Kubota C, Ganeko M, Takeda N. Exercise effects on sleep physiology. Frontiers in Neurology 2012;3:48. https://doi.org/10.3389/fneur.2012.00048.
Mendelson M, Borowik A, Michallet A -S., Perrin C, Monneret D, Faure P, et al. Sleep quality, sleep duration and physical activity in obese adolescents: effects of exercise training. Pediatric Obesity 2015;11:26–32. https://doi.org/10.1111/ijpo.12015.
Lang C, Kalak N, Brand S, Holsboer-Trachsler E, Pühse U, Gerber M. The relationship between physical activity and sleep from mid adolescence to early adulthood. A systematic review of methodological approaches and meta-analysis. Sleep Medicine Reviews 2016;28:32–45. https://doi.org/10.1016/j.smrv.2015.07.004.
Dolezal BA, Neufeld EV, Boland DM, Martin JL, Cooper CB. Interrelationship between Sleep and Exercise: A Systematic Review. Advances in Preventive Medicine 2017;2017:1–14. https://doi.org/10.1155/2017/1364387.
Wennman H, Kronholm E, Partonen T, Tolvanen A, Peltonen M, Vasankari T, et al. Physical activity and sleep profiles in Finnish men and women. BMC Public Health 2014;14:82. https://doi.org/10.1186/1471-2458-14-82.
McClain JJ, Lewin DS, Laposky AD, Kahle L, Berrigan D. Associations between physical activity, sedentary time, sleep duration and daytime sleepiness in US adults. Preventive Medicine 2014;66:68–73. https://doi.org/10.1016/j.ypmed.2014.06.003.
Alley JR, Mazzochi JW, Smith CJ, Morris DM, Collier SR. Effects of resistance exercise timing on sleep architecture and nocturnal blood pressure. Journal of Strength and Conditioning Research 2015;29:1378–85. https://doi.org/10.1519/jsc.0000000000000750.
Fairbrother K, Cartner B, Alley JR, Curry CD, Dickinson DL, Morris DM, et al. Effects of exercise timing on sleep architecture and nocturnal blood pressure in prehypertensives. Vascular Health and Risk Management 2014;10:691–8. https://doi.org/10.2147/VHRM.S73688.
Yamanaka Y, Hashimoto S, Takasu NN, Tanahashi Y, Nishide S, Honma S, et al. Morning and evening physical exercise differentially regulate the autonomic nervous system during nocturnal sleep in humans. American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 2015;309:R1112–21. https://doi.org/10.1152/ajpregu.00127.2015.
Mandolesi L, Polverino A, Montuori S, Foti F, Ferraioli G, Sorrentino P, et al. Effects of physical exercise on cognitive functioning and wellbeing: biological and psychological benefits. Frontiers in Psychology 2018;9:509. https://doi.org/10.3389/fpsyg.2018.00509.
Barbosa ÂP, Oliveira TM, Trindade PHE, Seidel SRT, Tokawa PKA, Jaramilo FM, et al. Sleep pattern interference in the cognitive performance of Lusitano horses. Animals 2024;14:334. https://doi.org/10.3390/ani14020334.
Barbosa ÂP, Oliveira TM, Seidel SRT, Tokawa PKA, Jaramillo FM, Roncati NV, et al. Could restricting horses' REM sleep improve dressage performance? Applied Animal Behaviour Science 2025;291:106740. https://doi.org/10.1016/j.applanim.2025.106740.
Greening L, Downing J, Amiouny D, Lekang L, McBride S. The effect of altering routine husbandry factors on sleep duration and memory consolidation in the horse. Applied Animal Behaviour Science 2021;236:105229. https://doi.org/10.1016/j.applanim.2021.105229.
Caanitz H, O'Leary L, Houpt K, Petersson K, Hintz H. Effect of exercise on equine behavior. Applied Animal Behaviour Science 1991;31:1–12. https://doi.org/10.1016/0168-1591(91)90148-q.
Hennes N, Briant C, Lorcet C, Ruet A, Lansade L. Behaviours exhibited during training predict physical tiredness in harness trotter horses. Applied Animal Behaviour Science 2024;274:106245. https://doi.org/10.1016/j.applanim.2024.106245.
Wells D, Irwin R. Auditory stimulation as enrichment for zoo-housed Asian elephants (Elephas maximus). Animal Welfare 2008;17:335–40. https://doi.org/10.1017/s0962728600027822.
Bateson M, Martin P. Measuring behaviour: An introductory guide. Cambridge: Cambridge University Press; 2021.
Borthwick EJ, Preshaw L, Wheeler-Launder C, Challinor C, Housby-Skeggs N, Boalch E, et al. Stable design influences relaxation and affiliative behavior in horses during short isolation bouts. Journal of Veterinary Behavior 2023;69–70:1–7. https://doi.org/10.1016/j.jveb.2023.10.003.
Schork IG, Manzo IA, Beiral De Oliveira MR, Costa FV, Palme R, Young RJ, et al. How environmental conditions affect sleep? An investigation in domestic dogs (Canis lupus familiaris). Behavioural Processes 2022;199:104662. https://doi.org/10.1016/j.beproc.2022.104662.
Koo TK, Li MY. A guideline of selecting and reporting intraclass correlation coefficients for reliability research. Journal of Chiropractic Medicine 2016;15:155–63. https://doi.org/10.1016/j.jcm.2016.02.012.
McKinney W. Data structures for statistical computing in Python, SciPy; 2010, p. 56–61. https://doi.org/10.25080/majora-92bf1922-00a.
Virtanen P, Gommers R, Oliphant TE, Haberland M, Reddy T, Cournapeau D, et al. SciPy 1.0: fundamental algorithms for scientific computing in Python. Nature Methods 2020;17:261–72. https://doi.org/10.1038/s41592-019-0686-2.
Hunter JD. Matplotlib: A 2D graphics environment. Computing in Science & Engineering 2007;9:90–5. https://doi.org/10.1109/mcse.2007.55.
Waskom M. Seaborn: statistical data visualization. Journal of Open Source Software 2021;6:3021. https://doi.org/10.21105/joss.03021.
Erlacher D, Vorster A. Sleep and muscle recovery – current concepts and empirical evidence. Current Issues in Sport Science (CISS) 2023;8:058. https://doi.org/10.36950/2023.2ciss058.
Doherty R, Madigan SM, Nevill A, Warrington G, Ellis JG. The sleep and recovery practices of athletes. Nutrients 2021;13:1330. https://doi.org/10.3390/nu13041330.
Frank MG, Heller HC. The function(s) of sleep. In: Landolt H-P, Dijk D-J, editors. Sleep-Wake Neurobiology and Pharmacology, Cham: Springer International Publishing; 2019, p. 3–34. https://doi.org/10.1007/164_2018_140.
Semplonius T, Willoughby T. Long-term links between physical activity and sleep quality. Medicine & Science in Sports & Exercise 2018;50:2418–24. https://doi.org/10.1249/mss.0000000000001706.
Lancel M, Droste SK, Sommer S, Reul JMHM. Influence of regular voluntary exercise on spontaneous and social stress-affected sleep in mice. European Journal of Neuroscience 2003;17:2171–9. https://doi.org/10.1046/j.1460-9568.2003.02658.x.
Thompson RS, Roller R, Greenwood BN, Fleshner M. Wheel running improves REM sleep and attenuates stress-induced flattening of diurnal rhythms in F344 rats. Stress 2016;19:312–24. https://doi.org/10.1080/10253890.2016.1174852.
Grady K, Cameron S, Kent SP, Barnes Heller H, Barry MM. Effect of an intervention of exercise on sleep and seizure frequency in idiopathic epileptic dogs. Journal of Small Animal Practice 2022;64:59–68. https://doi.org/10.1111/jsap.13568.
Kirschen GW, Jones JJ, Hale L. The impact of sleep duration on performance among competitive athletes: a systematic literature review. Clinical Journal of Sport Medicine: Official Journal of the Canadian Academy of Sport Medicine 2020;30:503–12. https://doi.org/10.1097/JSM.0000000000000622.
Kredlow MA, Capozzoli MC, Hearon BA, Calkins AW, Otto MW. The effects of physical activity on sleep: a meta-analytic review. Journal of Behavioral Medicine 2015;38:427–49. https://doi.org/10.1007/s10865-015-9617-6.
Lim J, Stephenson R. The role of ultradian rhythms in post-deprivation rebounds and diurnal rhythms of sleep and wakefulness in rats 2024. https://doi.org/10.1101/2024.02.04.578825.
Greening L, McBride S. A review of equine sleep: implications for equine welfare. Frontiers in Veterinary Science 2022;9:916737. https://doi.org/10.3389/fvets.2022.916737.
Greening L, Allen S, McBride S. Towards an objective measurement of sleep quality in non-human animals: using the horse as a model species for the creation of sleep quality indices. Biology Open 2023;12:bio059964. https://doi.org/10.1242/bio.059964.
Xie Y, Liu S, Chen X-J, Yu H-H, Yang Y, Wang W. Effects of exercise on sleep quality and insomnia in adults: a systematic review and meta-analysis of randomized controlled trials. Frontiers in Psychiatry 2021;12:664499. https://doi.org/10.3389/fpsyt.2021.664499.
Corral CJ, Miller M, Champagne FA, Schnyer DM, Baird B. Physical activity frequency patterns influence sleep architecture in young adults. Journal of Physical Activity and Health 2025;22:1042–50. https://doi.org/10.1123/jpah.2024-0844.
Ruckebusch Y. The relevance of drowsiness in the circadian cycle of farm animals. Animal Behaviour 1972;20:637–43. https://doi.org/10.1016/s0003-3472(72)80136-2.
Fuchs C, Kiefner LC, Kalus M, Reese S, Erhard M, Wöhr A-C. Polysomnography as a tool to asses equine welfare. In: Grant R, Allen T, Spink A, Sullivan M, editors. Measuring Behavior, Manchester, UK: Manchester Metropolitan University; 2018, p. 103–6.
Rault J-L, Waiblinger S, Boivin X, Hemsworth P. The power of a positive human–animal relationship for animal welfare. Frontiers in Veterinary Science 2020;7:590867. https://doi.org/10.3389/fvets.2020.590867.
Kis A, Gergely A, Galambos Á, Abdai J, Gombos F, Bódizs R, et al. Sleep macrostructure is modulated by positive and negative social experience in adult pet dogs. Proceedings of the Royal Society B: Biological Sciences 2017;284:20171883. https://doi.org/10.1098/rspb.2017.1883.
Cirelli C, Tononi G. Is sleep essential? PLoS Biology 2008;6:e216. https://doi.org/10.1371/journal.pbio.0060216.
Walker MP. The role of sleep in cognition and emotion. Annals of the New York Academy of Sciences 2009;1156:168–97. https://doi.org/10.1111/j.1749-6632.2009.04416.x.
Fullagar HHK, Skorski S, Duffield R, Hammes D, Coutts AJ, Meyer T. Sleep and athletic performance: the effects of sleep loss on exercise performance, and physiological and cognitive responses to exercise. Sports Medicine 2015;45:161–86. https://doi.org/10.1007/s40279-014-0260-0.
Zapalac K, Miller M, Champagne FA, Schnyer DM, Baird B. The effects of physical activity on sleep architecture and mood in naturalistic environments. Scientific Reports 2024;14:5637. https://doi.org/10.1038/s41598-024-56332-7.
Alnawwar MA, Alraddadi MI, Algethmi RA, Salem GA, Salem MA, Alharbi AA. The effect of physical activity on sleep quality and sleep disorder: a systematic review. Cureus 2023;15:e43595. https://doi.org/10.7759/cureus.43595.
Kelemen Z, Grimm H, Long M, Auer U, Jenner F. Recumbency as an equine welfare indicator in geriatric horses and horses with chronic orthopaedic disease. Animals 2021;11:3189. https://doi.org/10.3390/ani11113189.
Wonghanchao T, Sanigavatee K, Petchdee S, Chettaratanont K, Thongyen T, Wanichayanon B, et al. Heart rate and heart rate variability are affected by age and activity level in athletic horses. Veterinary Sciences 2025;12:624. https://doi.org/10.3390/vetsci12070624.
Oliveira TM, Zanotto GM, Trindade PHE, Baccarin RYA. Environment change causes a transient adverse impact on horse behavioral resting patterns. Applied Animal Behaviour Science 2025;282:106482. https://doi.org/10.1016/j.applanim.2024.106482.
Watson NF, Badr MS, Belenky G, Bliwise DL, Buxton OM, Buysse D, et al. Recommended amount of sleep for a healthy adult: a joint consensus statement of the American Academy of Sleep Medicine and Sleep Research Society. Sleep 2015;38:843–4. https://doi.org/10.5665/sleep.4716.
Kis A, Szakadát S, Gácsi M, Kovács E, Simor P, Török C, et al. The interrelated effect of sleep and learning in dogs (Canis familiaris); an EEG and behavioural study. Scientific Reports 2017;7:41873. https://doi.org/10.1038/srep41873.
Harbison ST. What have we learned about sleep from selective breeding strategies? Sleep 2022;45:zsac147. https://doi.org/10.1093/sleep/zsac147.
Ingram DK, London ED, Reynolds MA. Circadian rhythmicity and sleep: Effects of aging in laboratory animals. Neurobiology of Aging 1982;3:287–97. https://doi.org/10.1016/0197-4580(82)90017-3.
Stuber EF, Mathot KJ, Kempenaers B, Dingemanse NJ, Mueller JC. Sex-specific association between sleep and basal metabolic rate in great tits. Animal Behaviour 2015;109:15–22. https://doi.org/10.1016/j.anbehav.2015.08.004.
Villafuerte G, Miguel-Puga A, Murillo Rodríguez E, Machado S, Manjarrez E, Arias-Carrión O. Sleep deprivation and oxidative stress in animal models: a systematic review. Oxidative Medicine and Cellular Longevity 2015;2015:1–15. https://doi.org/10.1155/2015/234952.
Carreiro C, Reicher V, Kis A, Gácsi M. Attachment towards the Owner Is Associated with Spontaneous Sleep EEG Parameters in Family Dogs. Animals 2022;12:895. https://doi.org/10.3390/ani12070895.
Gessner N, Shinbashi M, Chuluun B, Heller C, Pittaras E. Handling, task complexity, time-of-day, and sleep deprivation as dynamic modulators of recognition memory in mice. Physiology & Behavior 2022;251:113803. https://doi.org/10.1016/j.physbeh.2022.113803.
Loftus JC, Harel R, Núñez CL, Crofoot MC. Ecological and social pressures interfere with homeostatic sleep regulation in the wild. eLife 2022;11:e73695. https://doi.org/10.7554/elife.73695.
Glenk L. Current perspectives on therapy dog welfare in animal-assisted interventions. Animals 2017;7:7. https://doi.org/10.3390/ani7020007.
Lewis A. What are the short and long-term impacts of animal assisted interventions on the therapy animals? Journal of Applied Animal Ethics Research 2024;6:135–57. https://doi.org/10.1163/25889567-bja10054.
Cockram MS, Murphy E, Ringrose S, Wemelsfelder F, Miedema HM, Sandercock DA. Behavioural and physiological measures following treadmill exercise as potential indicators to evaluate fatigue in sheep. Animal 2012;6:1491–502. https://doi.org/10.1017/s1751731112000638.
Gehrke EK, Baldwin A, Schiltz PM. Heart rate variability in horses engaged in equine-assisted activities. Journal of Equine Veterinary Science 2011;31:78–84. https://doi.org/10.1016/j.jevs.2010.12.007.
Tiemann I, Fijn LB, Bagaria M, Langen EMA, van der Staay FJ, Arndt SS, et al. Glucocorticoids in relation to behavior, morphology, and physiology as proxy indicators for the assessment of animal welfare. A systematic mapping review. Frontiers in Veterinary Science 2023;9:954607. https://doi.org/10.3389/fvets.2022.954607.
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