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Home / Equine Research Bank / Front Vet Sci / Exercise-related changes in the anabolic index (testosterone...
Frontiers in veterinary science2023; 10; 1148990; doi: 10.3389/fvets.2023.1148990

Exercise-related changes in the anabolic index (testosterone to cortisol ratio) and serum amyloid A concentration in endurance and racehorses at different fitness levels.

Abstract: Increased training loads in both human and equine athletes are generally implemented to improve their physical performance. These loads are tolerated only within appropriate training periodization with regard to recovery time. Otherwise, training overload causes failure in the systemic adaptation, which at first leads to overreaching, and progressively to overtraining syndrome (OTS). Exercise endocrinology, and anabolic/catabolic balance as an indicator of athlete performance status and OTS has continued to attract attention. In human medicine, changes in testosterone and cortisol levels, as well as the testosterone to cortisol ratio (T/C; anabolic index), are suggested to be sensitive stress markers. However, there is a lack of research investigating these parameters for use in equine sports medicine. The aim of the study was to investigate the differences in testosterone, cortisol, and T/C in response to a single training session in two types of equine sports: endurance and race, together with serum amyloid A (SAA), the main acute phase response indicator of physical effort, and the overall health status in horses. Two groups of horses were enrolled in the study: endurance ( = 12) and racehorses ( = 32) of different fitness level. Blood samples were obtained before and after the exercise. On average, T increased 2.5 times after the race training in experienced racehorses and dropped in endurance horses regardless the fitness level ( < 0.05). In endurance horses, a decrease in T/C occurred after training in inexperienced horses ( < 0.05). In racehorses, a T/C decrease occurred in the inexperienced group ( < 0.05) and an increase in the experienced ( < 0.01). In conclusion, T/C ratio was found to be a potentially reliable indicator of fitness status especially in racing horses. These findings provide insight into the physiological response of the horses to different types of exercise and the potential use of hormone levels as markers of performance and adaptation.
Copyright © 2023 Jowita, Izabela, Katarzyna and Olga.
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Publication Date: 2023-04-17 PubMed ID: 37138908PubMed Central: PMC10150884DOI: 10.3389/fvets.2023.1148990Google Scholar: Lookup
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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.

The research investigates how increased training loads affect hormone levels—specifically, testosterone, cortisol, and the testosterone/cortisol ratio (anabolic index)—in endurance and racehorses. An additional metric, serum amyloid A (SAA), is also investigated. The research finds that these hormonal markers potentially indicate the fitness level of the horses, and responses vary depending on the type of exercise.

Background and Aim

  • The background of this research lies in the understanding that more training improves physical performance, but it should be within the limit that the body can tolerate. If exceeded, the body falls into overreaching, then progressively into overtraining syndrome.
  • The researchers used testosterone and cortisol levels and their ratio as evidence of this systemic stress. These are considered to be good physiological stress markers in human medicine.
  • The study aimed to test these parameters in two types of sports horses—endurance and racehorses—and observe the changes in response to a single training session.
  • The study also measured serum amyloid A (SAA), an indicator that shows the body’s reaction to physical effort and gives an overall health status.

Methodology

  • Two categories of horses were involved in the study: 12 endurance horses and 32 racehorses. Their fitness level varied.
  • The researchers took blood samples before and after the exercise program to measure the target parameters: testosterone, cortisol, their ratio, and SAA.

Findings

  • Testosterone increased 2.5 times after race training in experienced racehorses, b ut it decreased in endurance horses, regardless of fitness level.
  • The testosterone/cortisol ratio decreased after training in inexperienced endurance horses, while it decreased for inexperienced racehorses and increased for experienced ones.
  • The testosterone/cortisol ratio can be a reliable indicator of the fitness status of a racing horse.

Conclusion

  • The findings suggest different exercises elicit different physiological responses in horses, and hormone levels could potentially be used as markers for performance and adaptation.

Cite This Article

APA
Grzędzicka J, Dąbrowska I, Malin K, Witkowska-Piłaszewicz O. (2023). Exercise-related changes in the anabolic index (testosterone to cortisol ratio) and serum amyloid A concentration in endurance and racehorses at different fitness levels. Front Vet Sci, 10, 1148990. https://doi.org/10.3389/fvets.2023.1148990

Publication

Frontiers in veterinary science
ISSN: 2297-1769
NlmUniqueID: 101666658
Country: Switzerland
Language: English
Volume: 10
Pages: 1148990
PII: 1148990

Researcher Affiliations

Grzędzicka, Jowita
  • Department of Large Animal Diseases and Clinic, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, Poland.
Dąbrowska, Izabela
  • Department of Large Animal Diseases and Clinic, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, Poland.
Malin, Katarzyna
  • Department of Large Animal Diseases and Clinic, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, Poland.
Witkowska-Piłaszewicz, Olga
  • Department of Large Animal Diseases and Clinic, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, Poland.

Conflict of Interest Statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

References

This article includes 81 references
  1. Athanasiou N, Bogdanis GC, Mastorakos G. Endocrine responses of the stress system to different types of exercise.. Rev Endocr Metab Disord 2023 Apr;24(2):251-266.
    doi: 10.1007/s11154-022-09758-1pmc: PMC10023776pubmed: 36242699google scholar: lookup
  2. Smith SM, Vale WW. The role of the hypothalamic-pituitary-adrenal axis in neuroendocrine responses to stress.. Dialogues Clin Neurosci 2006;8(4):383-95.
    doi: 10.31887/DCNS.2006.8.4/ssmithpmc: PMC3181830pubmed: 17290797google scholar: lookup
  3. Duclos M, Tabarin A. Exercise and the Hypothalamo-Pituitary-Adrenal Axis.. Front Horm Res 2016;47:12-26.
    doi: 10.1159/000445149pubmed: 27348531google scholar: lookup
  4. Baschetti R. Chronic fatigue syndrome: a form of Addison's disease.. J Intern Med 2000 Jun;247(6):737-9.
    doi: 10.1046/j.1365-2796.2000.00695.xpubmed: 10886497google scholar: lookup
  5. Coderre L, Srivastava AK, Chiasson JL. Role of glucocorticoid in the regulation of glycogen metabolism in skeletal muscle.. Am J Physiol 1991 Jun;260(6 Pt 1):E927-32.
    doi: 10.1152/ajpendo.1991.260.6.E927pubmed: 1905485google scholar: lookup
  6. Sellers TL, Jaussi AW, Yang HT, Heninger RW, Winder WW. Effect of the exercise-induced increase in glucocorticoids on endurance in the rat.. J Appl Physiol (1985) 1988 Jul;65(1):173-8.
    doi: 10.1152/jappl.1988.65.1.173pubmed: 3042739google scholar: lookup
  7. McEwen BS. The good side of "stress".. Stress 2019 Sep;22(5):524-525.
    doi: 10.1080/10253890.2019.1631794pubmed: 31237468google scholar: lookup
  8. Kraemer WJ, Ratamess NA, Hymer WC, Nindl BC, Fragala MS. Growth Hormone(s), Testosterone, Insulin-Like Growth Factors, and Cortisol: Roles and Integration for Cellular Development and Growth With Exercise.. Front Endocrinol (Lausanne) 2020;11:33.
    doi: 10.3389/fendo.2020.00033pmc: PMC7052063pubmed: 32158429google scholar: lookup
  9. Adlercreutz H, Härkönen M, Kuoppasalmi K, Näveri H, Huhtaniemi I, Tikkanen H, Remes K, Dessypris A, Karvonen J. Effect of training on plasma anabolic and catabolic steroid hormones and their response during physical exercise.. Int J Sports Med 1986 Jun;7 Suppl 1:27-8.
    doi: 10.1055/s-2008-1025798pubmed: 3744643google scholar: lookup
  10. Banfi G, Marinelli M, Roi GS, Agape V. Usefulness of free testosterone/cortisol ratio during a season of elite speed skating athletes.. Int J Sports Med 1993 Oct;14(7):373-9.
    doi: 10.1055/s-2007-1021195pubmed: 8244603google scholar: lookup
  11. Dąbrowska I, Grzędzicka J, Malin K, Pawliński B, Mickiewicz J, Witkowska-Piłaszewicz O. Intense leisure exploitation influences on horses hormonal reaction—preliminary study. Agriculture (2022) 12:1777.
    doi: 10.3390/agriculture12111777google scholar: lookup
  12. Urhausen A, Kullmer T, Kindermann W. A 7-week follow-up study of the behaviour of testosterone and cortisol during the competition period in rowers.. Eur J Appl Physiol Occup Physiol 1987;56(5):528-33.
    doi: 10.1007/BF00635365pubmed: 3653093google scholar: lookup
  13. Lac G, Maso F. Biological markers for the follow-up of athletes throughout the training season.. Pathol Biol (Paris) 2004 Feb;52(1):43-9.
    doi: 10.1016/S0369-8114(03)00049-Xpubmed: 14761713google scholar: lookup
  14. Yang W, Hu P. Skeletal muscle regeneration is modulated by inflammation.. J Orthop Translat 2018 Apr;13:25-32.
    doi: 10.1016/j.jot.2018.01.002pmc: PMC5892385pubmed: 29662788google scholar: lookup
  15. Zaldivar F, Wang-Rodriguez J, Nemet D, Schwindt C, Galassetti P, Mills PJ, Wilson LD, Cooper DM. Constitutive pro- and anti-inflammatory cytokine and growth factor response to exercise in leukocytes.. J Appl Physiol (1985) 2006 Apr;100(4):1124-33.
    doi: 10.1152/japplphysiol.00562.2005pubmed: 16357073google scholar: lookup
  16. Witkowska-Piłaszewicz O, Bąska P, Czopowicz M, Żmigrodzka M, Szczepaniak J, Szarska E, Winnicka A, Cywińska A. Changes in Serum Amyloid A (SAA) Concentration in Arabian Endurance Horses During First Training Season.. Animals (Basel) 2019 Jun 8;9(6).
    doi: 10.3390/ani9060330pmc: PMC6616404pubmed: 31181740google scholar: lookup
  17. da Silva FOC, Macedo DV. Exercício físico, processo inflamatório e adaptação: uma visão geral. Rev bras cineantropom desempenho hum (2011):320–8.
    doi: 10.5007/1980-0037.2011v13n4p320google scholar: lookup
  18. Smith LL. Tissue trauma: the underlying cause of overtraining syndrome?. J Strength Cond Res 2004 Feb;18(1):185-93.
    doi: 10.1519/1533-4287(2004)018<0185:tttuco>2.0.co;2pubmed: 14971991google scholar: lookup
  19. Lee KE, Kim JG, Lee H, Kim BS. Behavioral and cardiac responses in mature horses exposed to a novel object.. J Anim Sci Technol 2021 May;63(3):651-661.
    doi: 10.5187/jast.2021.e51pmc: PMC8203992pubmed: 34189512google scholar: lookup
  20. de Mira MC, Lamy E, Santos R, Williams J, Pinto MV, Martins PS, Rodrigues P, Marlin D. Salivary cortisol and eye temperature changes during endurance competitions.. BMC Vet Res 2021 Oct 14;17(1):329.
    doi: 10.1186/s12917-021-02985-9pmc: PMC8515720pubmed: 34649565google scholar: lookup
  21. Witkowska-Piłaszewicz O, Maśko M, Domino M, Winnicka A. Infrared Thermography Correlates with Lactate Concentration in Blood during Race Training in Horses.. Animals (Basel) 2020 Nov 9;10(11).
    doi: 10.3390/ani10112072pmc: PMC7695344pubmed: 33182281google scholar: lookup
  22. McGowan CM, Whitworth DJ. Overtraining syndrome in horses. Comparat Exerc Physiol (2008) 5:57–65.
    doi: 10.1017/S1478061508979202google scholar: lookup
  23. Cywinska A, Witkowski L, Szarska E, Schollenberger A, Winnicka A. Serum amyloid A (SAA) concentration after training sessions in Arabian race and endurance horses.. BMC Vet Res 2013 May 1;9:91.
    doi: 10.1186/1746-6148-9-91pmc: PMC3655847pubmed: 23634727google scholar: lookup
  24. Witkowska-Piłaszewicz O, Grzędzicka J, Seń J, Czopowicz M, Żmigrodzka M, Winnicka A, Cywińska A, Carter C. Stress response after race and endurance training sessions and competitions in Arabian horses.. Prev Vet Med 2021 Mar;188:105265.
    doi: 10.1016/j.prevetmed.2021.105265pubmed: 33497894google scholar: lookup
  25. López-Rivero JL, Agüera E, Monterde JG, Rodríguez-Barbudo MV, Miró F. Comparative study of muscle fiber type composition in the middle gluteal muscle of andalusian, thoroughbred and arabian horses. J Equine Vet (1989) 9:337–40.
    doi: 10.1016/S0737-0806(89)80072-3google scholar: lookup
  26. Cadegiani FA, Kater CE. Basal Hormones and Biochemical Markers as Predictors of Overtraining Syndrome in Male Athletes: The EROS-BASAL Study.. J Athl Train 2019 Aug;54(8):906-914.
    doi: 10.4085/1062-6050-148-18pmc: PMC6756603pubmed: 31386577google scholar: lookup
  27. Helms ER, Kwan K, Sousa CA, Cronin JB, Storey AG, Zourdos MC. Methods for Regulating and Monitoring Resistance Training.. J Hum Kinet 2020 Aug;74:23-42.
    doi: 10.2478/hukin-2020-0011pmc: PMC7706636pubmed: 33312273google scholar: lookup
  28. Sikorski EM, Wilson JM, Lowery RP, Joy JM, Laurent CM, Wilson SM, Hesson D, Naimo MA, Averbuch B, Gilchrist P. Changes in perceived recovery status scale following high-volume muscle damaging resistance exercise.. J Strength Cond Res 2013 Aug;27(8):2079-85.
    doi: 10.1519/JSC.0b013e31827e8e78pubmed: 23287827google scholar: lookup
  29. Häkkinen K, Pakarinen A, Alen M, Kauhanen H, Komi PV. Neuromuscular and hormonal adaptations in athletes to strength training in two years.. J Appl Physiol (1985) 1988 Dec;65(6):2406-12.
    doi: 10.1152/jappl.1988.65.6.2406pubmed: 3215840google scholar: lookup
  30. Hirschberg AL, Elings Knutsson J, Helge T, Godhe M, Ekblom M, Bermon S, Ekblom B. Effects of moderately increased testosterone concentration on physical performance in young women: a double blind, randomised, placebo controlled study.. Br J Sports Med 2020 May;54(10):599-604.
    doi: 10.1136/bjsports-2018-100525pubmed: 31615775google scholar: lookup
  31. Vingren JL, Kraemer WJ, Ratamess NA, Anderson JM, Volek JS, Maresh CM. Testosterone physiology in resistance exercise and training: the up-stream regulatory elements.. Sports Med 2010 Dec 1;40(12):1037-53.
    doi: 10.2165/11536910-000000000-00000pubmed: 21058750google scholar: lookup
  32. Wasserfurth P, Palmowski J, Hahn A, Krüger K. Reasons for and Consequences of Low Energy Availability in Female and Male Athletes: Social Environment, Adaptations, and Prevention.. Sports Med Open 2020 Sep 10;6(1):44.
    doi: 10.1186/s40798-020-00275-6pmc: PMC7483688pubmed: 32910256google scholar: lookup
  33. Hackney AC. Stress and the neuroendocrine system: the role of exercise as a stressor and modifier of stress.. Expert Rev Endocrinol Metab 2006 Nov 1;1(6):783-792.
    doi: 10.1586/17446651.1.6.783pmc: PMC2953272pubmed: 20948580google scholar: lookup
  34. Hackney AC. Effects of endurance exercise on the reproductive system of men: the "exercise-hypogonadal male condition".. J Endocrinol Invest 2008 Oct;31(10):932-8.
    doi: 10.1007/BF03346444pubmed: 19092301google scholar: lookup
  35. Wheeler GD, Singh M, Pierce WD, Epling WF, Cumming DC. Endurance training decreases serum testosterone levels in men without change in luteinizing hormone pulsatile release.. J Clin Endocrinol Metab 1991 Feb;72(2):422-5.
    doi: 10.1210/jcem-72-2-422pubmed: 1899423google scholar: lookup
  36. Hackney AC, Lane AR. Low testosterone in male endurance-trained distance runners: impact of years in training.. Hormones (Athens) 2018 Mar;17(1):137-139.
    doi: 10.1007/s42000-018-0010-zpubmed: 29858867google scholar: lookup
  37. Consitt LA, Copeland JL, Tremblay MS. Endogenous anabolic hormone responses to endurance versus resistance exercise and training in women.. Sports Med 2002;32(1):1-22.
    doi: 10.2165/00007256-200232010-00001pubmed: 11772159google scholar: lookup
  38. Horton R, Tait JF. Androstenedione production and interconversion rates measured in peripheral blood and studies on the possible site of its conversion to testosterone.. J Clin Invest 1966 Mar;45(3):301-13.
    doi: 10.1172/JCI105344pmc: PMC292699pubmed: 5904549google scholar: lookup
  39. Kirschner MA, Bardin CW. Androgen production and metabolism in normal and virilized women.. Metabolism 1972 Jul;21(7):667-88.
    doi: 10.1016/0026-0495(72)90090-xpubmed: 4562220google scholar: lookup
  40. Consitt LA, Copeland JL, Tremblay MS. Hormone responses to resistance vs. endurance exercise in premenopausal females.. Can J Appl Physiol 2001 Dec;26(6):574-87.
    doi: 10.1139/h01-032pubmed: 11842274google scholar: lookup
  41. Copeland JL, Consitt LA, Tremblay MS. Hormonal responses to endurance and resistance exercise in females aged 19-69 years.. J Gerontol A Biol Sci Med Sci 2002 Apr;57(4):B158-65.
    doi: 10.1093/gerona/57.4.b158pubmed: 11909881google scholar: lookup
  42. Bonen A, Keizer HA. Pituitary, ovarian, and adrenal hormone responses to marathon running.. Int J Sports Med 1987 Dec;8 Suppl 3:161-7.
    doi: 10.1055/s-2008-1025723pubmed: 3429092google scholar: lookup
  43. Keizer HA, Kuipers H, de Haan J, Janssen GM, Beckers E, Habets L, van Kranenburg G, Geurten P. Effect of a 3-month endurance training program on metabolic and multiple hormonal responses to exercise.. Int J Sports Med 1987 Dec;8 Suppl 3:154-60.
    doi: 10.1055/s-2008-1025722pubmed: 3429091google scholar: lookup
  44. Häkkinen K, Pakarinen A, Kraemer WJ, Newton RU, Alen M. Basal concentrations and acute responses of serum hormones and strength development during heavy resistance training in middle-aged and elderly men and women.. J Gerontol A Biol Sci Med Sci 2000 Feb;55(2):B95-105.
    doi: 10.1093/gerona/55.2.b95pubmed: 10737684google scholar: lookup
  45. Rowell LB. Human cardiovascular adjustments to exercise and thermal stress.. Physiol Rev 1974 Jan;54(1):75-159.
    doi: 10.1152/physrev.1974.54.1.75pubmed: 4587247google scholar: lookup
  46. Stachowicz M, Lebiedzińska A. The effect of diet components on the level of cortisol. Eur Food Res Technol (2016) 242:2001–9.
    doi: 10.1007/s00217-016-2772-3google scholar: lookup
  47. Papierska L, Rabijewski M, Misiorowski W. Glucocorticoid-induced osteoporosis. Krakow: Postępy Nauk Medycznych; (2007).
  48. Bateup HS, Booth A, Shirtcliff EA, Granger DA. Testosterone, cortisol, and women’s competition. Evol Hum Behav (2002) 23:181–92.
    doi: 10.1016/S1090-5138(01)00100-3google scholar: lookup
  49. Cayado P, Muñoz-Escassi B, Domínguez C, Manley W, Olabarri B, Sánchez de la Muela M, Castejon F, Marañon G, Vara E. Hormone response to training and competition in athletic horses.. Equine Vet J Suppl 2006 Aug;(36):274-8.
    doi: 10.1111/j.2042-3306.2006.tb05552.xpubmed: 17402431google scholar: lookup
  50. Fazio E, Medica P, Cravana C, Ferlazzo A. Effects of competition experience and transportation on the adrenocortical and thyroid responses of horses.. Vet Rec 2008 Dec 13;163(24):713-6.
    doi: 10.1136/vr.163.24.713pubmed: 19074788google scholar: lookup
  51. Filaire E, Alix D, Ferrand C, Verger M. Psychophysiological stress in tennis players during the first single match of a tournament.. Psychoneuroendocrinology 2009 Jan;34(1):150-7.
    doi: 10.1016/j.psyneuen.2008.08.022pubmed: 18845399google scholar: lookup
  52. Jiménez M, Aguilar R, Alvero-Cruz JR. Effects of victory and defeat on testosterone and cortisol response to competition: evidence for same response patterns in men and women.. Psychoneuroendocrinology 2012 Sep;37(9):1577-81.
    doi: 10.1016/j.psyneuen.2012.02.011pubmed: 22429747google scholar: lookup
  53. Mircean M, Giurgiu G, Mircean V, Zinveliu E. Serum cortisol variation of sport horses in relation with the level of training and effort intensity. Bull Univ Agric Sci Vet Med Cluj-Napoca (2007) 64:488–92.
  54. Viru A, Viru M. Cortisol--essential adaptation hormone in exercise.. Int J Sports Med 2004 Aug;25(6):461-4.
    doi: 10.1055/s-2004-821068pubmed: 15346236google scholar: lookup
  55. Ambroży T, Rydzik Ł, Obmiński Z, Błach W, Serafin N, Błach B, Jaszczur-Nowicki J, Ozimek M. The Effect of High-Intensity Interval Training Periods on Morning Serum Testosterone and Cortisol Levels and Physical Fitness in Men Aged 35-40 Years.. J Clin Med 2021 May 15;10(10).
    doi: 10.3390/jcm10102143pmc: PMC8156527pubmed: 34063524google scholar: lookup
  56. Cofré-Bolados C, Reuquen-López P, Herrera-Valenzuela T, Orihuela-Diaz P, Garcia-Hermoso A, Hackney AC. Testosterone and cortisol responses to HIIT and continuous aerobic exercise in active young men. Sustainability (2019) 11:6069.
    doi: 10.3390/sᄡ6069google scholar: lookup
  57. Fry AC, Schilling BK, Fleck SJ, Kraemer WJ. Relationships between competitive wrestling success and neuroendocrine responses.. J Strength Cond Res 2011 Jan;25(1):40-5.
    doi: 10.1519/JSC.0b013e3181fef62fpubmed: 21116194google scholar: lookup
  58. Zurek G, Danek N, Żurek A, Nowak-Kornicka J, Żelaźniewicz A, Orzechowski S, Stefaniak T, Nawrat M, Kowal M. Effects of Dominance and Sprint Interval Exercise on Testosterone and Cortisol Levels in Strength-, Endurance-, and Non-Training Men.. Biology (Basel) 2022 Jun 24;11(7).
    doi: 10.3390/biology11070961pmc: PMC9312330pubmed: 36101342google scholar: lookup
  59. Alén M, Pakarinen A, Häkkinen K, Komi PV. Responses of serum androgenic-anabolic and catabolic hormones to prolonged strength training.. Int J Sports Med 1988 Jun;9(3):229-33.
    doi: 10.1055/s-2007-1025011pubmed: 3410630google scholar: lookup
  60. Herbert P, Hayes LD, Sculthorpe NF, Grace FM. HIIT produces increases in muscle power and free testosterone in male masters athletes.. Endocr Connect 2017 Oct;6(7):430-436.
    doi: 10.1530/EC-17-0159pmc: PMC5551442pubmed: 28794164google scholar: lookup
  61. Lac G, Berthon P. Changes in cortisol and testosterone levels and T/C ratio during an endurance competition and recovery.. J Sports Med Phys Fitness 2000 Jun;40(2):139-44.
    pubmed: 11034434
  62. Passelergue P, Lac G. Saliva cortisol, testosterone and T/C ratio variations during a wrestling competition and during the post-competitive recovery period.. Int J Sports Med 1999 Feb;20(2):109-13.
    doi: 10.1055/s-2007-971102pubmed: 10190771google scholar: lookup
  63. Ferlazzo N, Currò M, Saija C, Naccari F, Ientile R, Di Mauro D, Trimarchi F, Caccamo D. Saliva testing as noninvasive way for monitoring exercise-dependent response in teenage elite water polo players: A cohort study.. Medicine (Baltimore) 2021 Nov 19;100(46):e27847.
    doi: 10.1097/MD.0000000000027847pmc: PMC8601290pubmed: 34797320google scholar: lookup
  64. Gentles J, Hornsby GW, Gray HS, Miller JA, Dotterweich AR, Stuart CA. Changes in cell free DNA during a college soccer season. J Trainol (2015) 4:25–31.
    doi: 10.17338/trainology.4.1_25google scholar: lookup
  65. Karkoulias K, Habeos I, Charokopos N, Tsiamita M, Mazarakis A, Pouli A, Spiropoulos K. Hormonal responses to marathon running in non-elite athletes.. Eur J Intern Med 2008 Dec;19(8):598-601.
    doi: 10.1016/j.ejim.2007.06.032pubmed: 19046725google scholar: lookup
  66. Kłapcińska B, Waśkiewicz Z, Chrapusta SJ, Sadowska-Krępa E, Czuba M, Langfort J. Metabolic responses to a 48-h ultra-marathon run in middle-aged male amateur runners.. Eur J Appl Physiol 2013 Nov;113(11):2781-93.
    doi: 10.1007/s00421-013-2714-8pmc: PMC3824198pubmed: 24002469google scholar: lookup
  67. Kupchak BR, Kraemer WJ, Hoffman MD, Phinney SD, Volek JS. The impact of an ultramarathon on hormonal and biochemical parameters in men.. Wilderness Environ Med 2014 Sep;25(3):278-88.
    doi: 10.1016/j.wem.2014.03.013pubmed: 24931590google scholar: lookup
  68. Vaamonde D, García-Manso JM, Algar-Santacruz C, Abbasi A, Sarmiento S, Valverde-Esteve T. Behaviour of salivary testosterone and cortisol in men during an Ironman Triathlon.. Eur J Sport Sci 2022 Sep;22(9):1335-1342.
    doi: 10.1080/17461391.2021.1955011pubmed: 34256680google scholar: lookup
  69. Bommasamudram T, Ravindrakumar A, Varamenti E, Tod D, Edwards BJ, Peter IG, Pullinger SA. Daily variation in time-trial sporting performance: A systematic review.. Chronobiol Int 2022 Sep;39(9):1167-1182.
    doi: 10.1080/07420528.2022.2090373pubmed: 35815685google scholar: lookup
  70. Varamenti E, Beattie C, Tod D, Bommasamudram T, Savoia C, Pullinger SA. Acute and long-term variations in variables related to redox, inflammation and hormonal status in male football players: a systematic review and recommendations. J Ortho Sports Med (2022) 4:246–62.
    doi: 10.26502/josm.511500062google scholar: lookup
  71. Cray C. Acute phase proteins in animals.. Prog Mol Biol Transl Sci 2012;105:113-50.
    doi: 10.1016/B978-0-12-394596-9.00005-6pmc: PMC7149966pubmed: 22137431google scholar: lookup
  72. Crisman MV, Scarratt WK, Zimmerman KL. Blood proteins and inflammation in the horse.. Vet Clin North Am Equine Pract 2008 Aug;24(2):285-97, vi.
    doi: 10.1016/j.cveq.2008.03.004pubmed: 18652956google scholar: lookup
  73. Jacobsen S, Andersen PH. The acute phase protein serum amyloid A (SAA) as a marker of inflammation in horses. Equine Vet Educ (2007) 19:38–46.
    doi: 10.1111/j.2042-3292.2007.tb00550.xgoogle scholar: lookup
  74. Petersen HH, Nielsen JP, Heegaard PM. Application of acute phase protein measurements in veterinary clinical chemistry.. Vet Res 2004 Mar-Apr;35(2):163-87.
    doi: 10.1051/vetres:2004002pubmed: 15099494google scholar: lookup
  75. Kristensen L, Buhl R, Nostell K, Bak L, Petersen E, Lindholm M, Jacobsen S. Acute exercise does not induce an acute phase response (APR) in Standardbred trotters.. Can J Vet Res 2014 Apr;78(2):97-102.
    pmc: PMC3962284pubmed: 24688170
  76. Turło A, Cywińska A, Czopowicz M, Witkowski L, Jaśkiewicz A, Winnicka A. Racing induces changes in the blood concentration of serum amyloid A in thoroughbred racehorses. J Equine Vet (2016) 36:15–8.
    doi: 10.1016/j.jevs.2015.09.008google scholar: lookup
  77. Cywinska A, Gorecka R, Szarska E, Witkowski L, Dziekan P, Schollenberger A. Serum amyloid A level as a potential indicator of the status of endurance horses.. Equine Vet J Suppl 2010 Nov;(38):23-7.
    doi: 10.1111/j.2042-3306.2010.00280.xpubmed: 21058978google scholar: lookup
  78. Nolen-Walston R. How to interpret serum amyloid A concentrations. Am Assoc Equine Pract (2015) 61:130–7.
  79. Liburt NR, Adams AA, Betancourt A, Horohov DW, McKeever KH. Exercise-induced increases in inflammatory cytokines in muscle and blood of horses.. Equine Vet J Suppl 2010 Nov;(38):280-8.
    doi: 10.1111/j.2042-3306.2010.00275.xpubmed: 21059019google scholar: lookup
  80. Bornstein SR, Engeland WC, Ehrhart-Bornstein M, Herman JP. Dissociation of ACTH and glucocorticoids.. Trends Endocrinol Metab 2008 Jul;19(5):175-80.
    doi: 10.1016/j.tem.2008.01.009pubmed: 18394919google scholar: lookup
  81. Hayes LD, Bickerstaff GF, Baker JS. Interactions of cortisol, testosterone, and resistance training: influence of circadian rhythms.. Chronobiol Int 2010 Jun;27(4):675-705.
    doi: 10.3109/07420521003778773pubmed: 20560706google scholar: lookup

Citations

This article has been cited 10 times.
  1. Reemtsma FP, Giers J, Horstmann S, Stoeckle SD, Gehlen H. Evaluation of Concentration Changes in Plasma Amino Acids and Their Metabolites in Eventing Horses During Cross-Country Competitions as Potential Performance Predictors. Animals (Basel) 2025 Dec 17;15(24).
    doi: 10.3390/ani15243640pubmed: 41463924google scholar: lookup
  2. 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).
    doi: 10.1242/jeb.250956pubmed: 41199666google scholar: lookup
  3. Kiełbik P, Witkowska-Piłaszewicz O. Iron Status in Sport Horses: Is It Important for Equine Athletes?. Int J Mol Sci 2025 Jun 12;26(12).
    doi: 10.3390/ijms26125653pubmed: 40565115google scholar: lookup
  4. Arfuso F, Rizzo M, Perillo L, Arrigo F, Giudice E, Piccione G, Faggio C, Monteverde V. The Effect of Ambient Temperature, Relative Humidity, and Temperature-Humidity Index on Stress Hormone and Inflammatory Response in Exercising Adult Standardbred Horses. Animals (Basel) 2025 May 15;15(10).
    doi: 10.3390/ani15101436pubmed: 40427313google scholar: lookup
  5. Milczek-Haduch D, Żmigrodzka M, Witkowska-Piłaszewicz O. Extracellular Vesicles in Sport Horses: Potential Biomarkers and Modulators of Exercise Adaptation and Therapeutics. Int J Mol Sci 2025 May 3;26(9).
    doi: 10.3390/ijms26094359pubmed: 40362597google scholar: lookup
  6. Chang X, Zhang Z, Yao X, Meng J, Ren W, Zeng Y. Lipidomics and biochemical profiling of adult Yili horses in a 26 km endurance race: exploring metabolic adaptations. Front Vet Sci 2025;12:1597739.
    doi: 10.3389/fvets.2025.1597739pubmed: 40331217google scholar: lookup
  7. Miguel-Ortega Á, Calleja-González J, Mielgo-Ayuso J. Interactions between Stress Levels and Hormonal Responses Related to Sports Performance in Pro Women's Basketball Team. J Funct Morphol Kinesiol 2024 Jul 31;9(3).
    doi: 10.3390/jfmk9030133pubmed: 39189218google scholar: lookup
  8. Witkowska-Piłaszewicz O, Malin K, Dąbrowska I, Grzędzicka J, Ostaszewski P, Carter C. Immunology of Physical Exercise: Is Equus caballus an Appropriate Animal Model for Human Athletes?. Int J Mol Sci 2024 May 10;25(10).
    doi: 10.3390/ijms25105210pubmed: 38791248google scholar: lookup
  9. Miglio A, Falcinelli E, Cappelli K, Mecocci S, Mezzasoma AM, Antognoni MT, Gresele P. Effect of Regular Training on Platelet Function in Untrained Thoroughbreds. Animals (Basel) 2024 Jan 27;14(3).
    doi: 10.3390/ani14030414pubmed: 38338057google scholar: lookup
  10. Reißmann M, Rajavel A, Kokov ZA, Schmitt AO. Identification of Differentially Expressed Genes after Endurance Runs in Karbadian Horses to Determine Candidates for Stress Indicators and Performance Capability. Genes (Basel) 2023 Oct 24;14(11).
    doi: 10.3390/genes14111982pubmed: 38002925google scholar: lookup
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