FREE SHIPPING over $40
OVER 9000 FIVE-STAR REVIEWS
5% OFF ALL SUBSCRIPTIONS
100% HAPPINESS GUARANTEE
Analyze Diet
0
Home / Equine Research Bank / Eur J Appl Physiol Occup Physiol / Effects of exercise intensity and environmental stress on in...
European journal of applied physiology and occupational physiology1996; 74(1-2); 60-66; doi: 10.1007/BF00376495

Effects of exercise intensity and environmental stress on indices of oxidative stress and iron homeostasis during exercise in the horse.

Abstract: The effects of prolonged variable-intensity and short-term high-intensity exercise on indices of oxidative stress and iron homeostasis were compared in six fit horses under cool [20 degrees C, 40% relative humidity (RH)] or hot/humid (30 degrees C, 80% RH) environmental conditions. The exercise protocols were designed to simulate equine competition, including racing (intense exercise) or the speed and endurance phase of a 3-day event (prolonged exercise). Increased plasma concentrations of lipid hydroperoxides and haemolysate concentrations of oxidised glutathione (GSSG) were measured within 30 min of the completion of exercise, indicating production of reactive oxygen species (ROS) and lipid membrane peroxidation. The horses were unable to complete the prolonged exercise protocol at high temperature and humidity. This coincided with higher maximal values of lipid hydroperoxides [138.2 (17.7) microM and GSSG [110.6 (18.2) microM], compared to high-intensity [105.2 (14.9) microM and 63.6 (8.6) microM, respectively] or prolonged [100.7 (18.7) microM and 86.2 (9.1) microM, respectively] exercise performed under cooler environmental conditions. Significant correlations were found between the duration of the final stage of exercise during hot/humid environmental conditions and increased levels of lipid hydroperoxides (r = 0.85), GSSG (r = 0.94), xanthine (r = 0.92) and uric acid (r = 0.96). Exercise also decreased the iron (Fe)-binding antioxidant activity of the plasma and increased the total plasma Fe levels, although this was only significant for prolonged exercise in ambient conditions. There was no detectable free Fe in the plasma at any stage of exercise. Other changes in biochemical parameters had returned to pre-exercise levels within 24 h after exercise. The results show that exercise can induce changes in biochemical parameters that are indicative of oxidative stress in the fit horse and that this was, exacerbated during exercise at high temperature and humidity.
Get Full Text
Publication Date: 1996-01-01 PubMed ID: 8891501DOI: 10.1007/BF00376495Google 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.
LinkedInCopy
  • Journal Article
  • Research Support
  • Non-U.S. Gov't

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 article investigates the effects of different exercise intensities and environmental conditions on oxidative stress and iron levels in fit horses. The study compares the impact of prolonged variable-intensity exercise and short-term high-intensity exercise under cool and hot/humid conditions, with significant findings related to exercise-induced oxidative stress and iron homeostasis alterations in horses.

Study Information

  • The study was conducted on six fit horses and aimed to simulate the conditions that these horses could face during competition, such as intense exercise during a race or prolonged exercise over a three-day event.
  • The researchers used two types of environmental conditions, cool (20 degrees Celsius and 40% relative humidity) and hot/humid (30 degrees Celsius and 80% relative humidity), to assess the impacts of different exercise intensities.

Exercise Impact on Oxidative Stress in Horses

  • Following each exercise, increased plasma concentrations of lipid hydroperoxides and hemolysate concentrations of oxidized glutathione (GSSG) were observed within 30 minutes. These markers indicate the production of reactive oxygen species (ROS) and the occurrence of lipid membrane peroxidation, signs of oxidative stress.
  • The horses struggled to complete prolonged exercise in a hot and humid environment. In these conditions, higher maximum values of lipid hydroperoxides and GSSG were observed compared to measurements from high-intensity or prolonged exercise under cooler conditions.

Correlation Between Environmental Conditions and Oxidative Stress

  • Significant correlations were found between the duration of the final stage of exercise under hot/humid conditions and increased levels of lipid hydroperoxides and GSSG. This suggests that the intensity and duration of exercise in these extreme conditions could have caused an increase in oxidative stress.

Exercise Impact on Iron Levels in Horses

  • Exercise was shown to decrease the iron (Fe)-binding antioxidant activity of plasma and increase total plasma Fe levels. However, this was only significant for prolonged exercise in ambient conditions.
  • Crucially, there was no detectable free iron in the plasma at any stage of exercise, which means that the body’s iron homeostasis mechanisms continued to function effectively.

Return to Pre-Exercise Levels

  • Chemical parameters associated with oxidative stress generally returned to pre-exercise levels within 24 hours after exercise. So, while exercise caused short-term changes, these were not persistent.

Conclusions

  • The study concludes that exercise can cause temporary changes in biochemical parameters indicating levels of oxidative stress in fit horses. This effect is exacerbated when exercise occurs under high temperature and humidity conditions.

Cite This Article

APA
Mills PC, Smith NC, Casas I, Harris P, Harris RC, Marlin DJ. (1996). Effects of exercise intensity and environmental stress on indices of oxidative stress and iron homeostasis during exercise in the horse. Eur J Appl Physiol Occup Physiol, 74(1-2), 60-66. https://doi.org/10.1007/BF00376495

Publication

European journal of applied physiology and occupational physiology
ISSN: 0301-5548
NlmUniqueID: 0410266
Country: Germany
Language: English
Volume: 74
Issue: 1-2
Pages: 60-66

Researcher Affiliations

Mills, P C
  • Equine Centre, Animal Health Trust, Newmarket, UK.
Smith, N C
    Casas, I
      Harris, P
        Harris, R C
          Marlin, D J

            MeSH Terms

            • Animals
            • Female
            • Glutathione / metabolism
            • Homeostasis / physiology
            • Horses
            • Iron / blood
            • Lipid Peroxides / metabolism
            • Male
            • Oxidative Phosphorylation
            • Oxidative Stress / physiology
            • Oxygen Consumption / physiology
            • Physical Exertion / physiology
            • Purine Nucleotides / metabolism
            • Reactive Oxygen Species / metabolism

            References

            This article includes 37 references
            1. Newham DJ, Jones DA, Tolfree SE, Edwards RH. Skeletal muscle damage: a study of isotope uptake, enzyme efflux and pain after stepping.. Eur J Appl Physiol Occup Physiol 1986;55(1):106-12.
              pubmed: 3009175doi: 10.1007/BF00422903google scholar: lookup
            2. Witt EH, Reznick AZ, Viguie CA, Starke-Reed P, Packer L. Exercise, oxidative damage and effects of antioxidant manipulation.. J Nutr 1992 Mar;122(3 Suppl):766-73.
              pubmed: 1514950doi: 10.1093/jn/122.suppl_3.766google scholar: lookup
            3. Sahlin K, Ekberg K, Cizinsky S. Changes in plasma hypoxanthine and free radical markers during exercise in man.. Acta Physiol Scand 1991 Jun;142(2):275-81.
              pubmed: 1877376doi: 10.1111/j.1748-1716.1991.tb09157.xgoogle scholar: lookup
            4. Pyke S, Lew H, Quintanilha A. Severe depletion in liver glutathione during physical exercise.. Biochem Biophys Res Commun 1986 Sep 30;139(3):926-31.
              pubmed: 3768007doi: 10.1016/s0006-291x(86)80266-2google scholar: lookup
            5. Mills PC, Dunnett M, Smith NC. The pharmacokinetics or oral and intravenous allopurinol and intravenous oxypurinol in the horse.. J Vet Pharmacol Ther 1995 Dec;18(6):451-6.
              pubmed: 8789699doi: 10.1111/j.1365-2885.1995.tb00625.xgoogle scholar: lookup
            6. Sjödin B, Hellsten Westing Y, Apple FS. Biochemical mechanisms for oxygen free radical formation during exercise.. Sports Med 1990 Oct;10(4):236-54.
              pubmed: 2247725doi: 10.2165/00007256-199010040-00003google scholar: lookup
            7. Selby GB, Eichner ER. Endurance swimming, intravascular hemolysis, anemia, and iron depletion. New perspective on athlete's anemia.. Am J Med 1986 Nov;81(5):791-4.
              pubmed: 3776985doi: 10.1016/0002-9343(86)90347-5google scholar: lookup
            8. Hellsten Y, Ahlborg G, Jensen-Urstad M, Sjödin B. Indication of in vivo xanthine oxidase activity in human skeletal muscle during exercise.. Acta Physiol Scand 1988 Sep;134(1):159-60.
              pubmed: 3239420doi: 10.1111/j.1748-1716.1988.tb08475.xgoogle scholar: lookup
            9. Barclay JK, Hansel M. Free radicals may contribute to oxidative skeletal muscle fatigue.. Can J Physiol Pharmacol 1991 Feb;69(2):279-84.
              pubmed: 2054745doi: 10.1139/y91-043google scholar: lookup
            10. Reed DJ. Glutathione: toxicological implications.. Annu Rev Pharmacol Toxicol 1990;30:603-31.
              pubmed: 2188580doi: 10.1146/annurev.pa.30.040190.003131google scholar: lookup
            11. Harris RC, Marlin DJ, Snow DH, Harkness RA. Muscle ATP loss and lactate accumulation at different work intensities in the exercising Thoroughbred horse.. Eur J Appl Physiol Occup Physiol 1991;62(4):235-44.
              pubmed: 2044532doi: 10.1007/BF00571546google scholar: lookup
            12. Pepper JR, Mumby S, Gutteridge JM. Transient iron-overload with bleomycin-detectable iron present during cardiopulmonary bypass surgery.. Free Radic Res 1994 Aug;21(2):53-8.
              pubmed: 7522839doi: 10.3109/10715769409056556google scholar: lookup
            13. Mills BJ, Richie JP Jr, Lang CA. Sample processing alters glutathione and cysteine values in blood.. Anal Biochem 1990 Feb 1;184(2):263-7.
              pubmed: 2327570doi: 10.1016/0003-2697(90)90678-3google scholar: lookup
            14. Jenkins RR. Free radical chemistry. Relationship to exercise.. Sports Med 1988 Mar;5(3):156-70.
              pubmed: 3285435doi: 10.2165/00007256-198805030-00003google scholar: lookup
            15. Jacinto SM, Jandhyala BS. Comparative evaluation of the acute effects of oxygen free radicals on myocardial contractility in anesthetized dogs with those occurring in the early stages of splanchnic artery occlusion and hemorrhagic shock.. Free Radic Biol Med 1994 Aug;17(2):171-9.
              pubmed: 7959176doi: 10.1016/0891-5849(94)90113-9google scholar: lookup
            16. Duthie GG, Robertson JD, Maughan RJ, Morrice PC. Blood antioxidant status and erythrocyte lipid peroxidation following distance running.. Arch Biochem Biophys 1990 Oct;282(1):78-83.
              pubmed: 2221920doi: 10.1016/0003-9861(90)90089-hgoogle scholar: lookup
            17. Sen CK, Marin E, Kretzschmar M, Hänninen O. Skeletal muscle and liver glutathione homeostasis in response to training, exercise, and immobilization.. J Appl Physiol (1985) 1992 Oct;73(4):1265-72.
              pubmed: 1360001doi: 10.1152/jappl.1992.73.4.1265google scholar: lookup
            18. Gutteridge JM, Rowley DA, Halliwell B, Cooper DF, Heeley DM. Copper and iron complexes catalytic for oxygen radical reactions in sweat from human athletes.. Clin Chim Acta 1985 Feb 15;145(3):267-73.
              pubmed: 2985297doi: 10.1016/0009-8981(85)90033-6google scholar: lookup
            19. Leeuwenburgh C, Ji LL. Glutathione depletion in rested and exercised mice: biochemical consequence and adaptation.. Arch Biochem Biophys 1995 Feb 1;316(2):941-9.
              pubmed: 7864653doi: 10.1006/abbi.1995.1125google scholar: lookup
            20. Novelli GP, Falsini S, Bracciotti G. Exogenous glutathione increases endurance to muscle effort in mice.. Pharmacol Res 1991 Feb;23(2):149-55.
              pubmed: 2062790doi: 10.1016/s1043-6618(05)80116-1google scholar: lookup
            21. Cramer GL, Miller JF Jr, Pendleton RB, Lands WE. Iodometric measurement of lipid hydroperoxides in human plasma.. Anal Biochem 1991 Mar 2;193(2):204-11.
              pubmed: 1872469doi: 10.1016/0003-2697(91)90010-qgoogle scholar: lookup
            22. Taylor C, Rogers G, Goodman C, Baynes RD, Bothwell TH, Bezwoda WR, Kramer F, Hattingh J. Hematologic, iron-related, and acute-phase protein responses to sustained strenuous exercise.. J Appl Physiol (1985) 1987 Feb;62(2):464-9.
              pubmed: 2435698doi: 10.1152/jappl.1987.62.2.464google scholar: lookup
            23. Skinner JS, McLellan TM. The transition from aerobic to anaerobic metabolism.. Res Q Exerc Sport 1980 Mar;51(1):234-48.
              pubmed: 7394286doi: 10.1080/02701367.1980.10609285google scholar: lookup
            24. Weight LM, Alexander D, Jacobs P. Strenuous exercise: analogous to the acute-phase response?. Clin Sci (Lond) 1991 Nov;81(5):677-83.
              pubmed: 1721863doi: 10.1042/cs0810677google scholar: lookup
            25. Kimber RJ, Rudzki Z, Blunden RW. Clinching the diagnosis: 1. Iron deficiency and iron overload: serum ferritin and serum iron in clinical medicine.. Pathology 1983 Oct;15(4):497-503.
              pubmed: 6674879doi: 10.3109/00313028309085180google scholar: lookup
            26. Criswell D, Powers S, Dodd S, Lawler J, Edwards W, Renshler K, Grinton S. High intensity training-induced changes in skeletal muscle antioxidant enzyme activity.. Med Sci Sports Exerc 1993 Oct;25(10):1135-40.
              pubmed: 8231758
            27. Ji LL, Fu R. Responses of glutathione system and antioxidant enzymes to exhaustive exercise and hydroperoxide.. J Appl Physiol (1985) 1992 Feb;72(2):549-54.
              pubmed: 1559931doi: 10.1152/jappl.1992.72.2.549google scholar: lookup
            28. Hughes H, Jaeschke H, Mitchell JR. Measurement of oxidant stress in vivo.. Methods Enzymol 1990;186:681-5.
              pubmed: 2233327doi: 10.1016/0076-6879(90)86167-tgoogle scholar: lookup
            29. Halliwell B, Gutteridge JM. The antioxidants of human extracellular fluids.. Arch Biochem Biophys 1990 Jul;280(1):1-8.
              pubmed: 2191627doi: 10.1016/0003-9861(90)90510-6google scholar: lookup
            30. Kehrer JP. Free radicals as mediators of tissue injury and disease.. Crit Rev Toxicol 1993;23(1):21-48.
              pubmed: 8471159doi: 10.3109/10408449309104073google scholar: lookup
            31. Németh I, Boda D. Blood glutathione redox ratio as a parameter of oxidative stress in premature infants with IRDS.. Free Radic Biol Med 1994 Mar;16(3):347-53.
              pubmed: 8063198doi: 10.1016/0891-5849(94)90036-1google scholar: lookup
            32. Gohil K, Viguie C, Stanley WC, Brooks GA, Packer L. Blood glutathione oxidation during human exercise.. J Appl Physiol (1985) 1988 Jan;64(1):115-9.
              pubmed: 3356628doi: 10.1152/jappl.1988.64.1.115google scholar: lookup
            33. Lew H, Pyke S, Quintanilha A. Changes in the glutathione status of plasma, liver and muscle following exhaustive exercise in rats.. FEBS Lett 1985 Jun 17;185(2):262-6.
              pubmed: 3996604doi: 10.1016/0014-5793(85)80919-4google scholar: lookup
            34. Lovlin R, Cottle W, Pyke I, Kavanagh M, Belcastro AN. Are indices of free radical damage related to exercise intensity.. Eur J Appl Physiol Occup Physiol 1987;56(3):313-6.
              pubmed: 3569239doi: 10.1007/BF00690898google scholar: lookup
            35. Sen CK, Atalay M, Hänninen O. Exercise-induced oxidative stress: glutathione supplementation and deficiency.. J Appl Physiol (1985) 1994 Nov;77(5):2177-87.
              pubmed: 7868431doi: 10.1152/jappl.1994.77.5.2177google scholar: lookup
            36. Butler PJ, Woakes AJ, Smale K, Roberts CA, Hillidge CJ, Snow DH, Marlin DJ. Respiratory and cardiovascular adjustments during exercise of increasing intensity and during recovery in thoroughbred racehorses.. J Exp Biol 1993 Jun;179:159-80.
              pubmed: 8340728doi: 10.1242/jeb.179.1.159google scholar: lookup
            37. Smith NC, Dunnett M, Mills PC. Simultaneous quantitation of oxidised and reduced glutathione in equine biological fluids by reversed-phase high-performance liquid chromatography using electrochemical detection.. J Chromatogr B Biomed Appl 1995 Nov 3;673(1):35-41.
              pubmed: 8925072doi: 10.1016/0378-4347(95)00245-egoogle scholar: lookup

            Citations

            This article has been cited 20 times.
            1. Bollinger L, Bartel A, Weber C, Gehlen H. Pre-Ride Biomarkers and Endurance Horse Welfare: Analyzing the Impact of the Elimination of Superoxide Dismutase, δ-Aminolevulinic-Dehydratase, Thiobarbituric Acid Reactive Substances, Iron, and Serum Amyloid A Levels in Elite 160 km Endurance Rides. Animals (Basel) 2023 May 17;13(10).
              doi: 10.3390/ani13101670pubmed: 37238102google scholar: lookup
            2. Gołyński M, Metyk M, Ciszewska J, Szczepanik MP, Fitch G, Bęczkowski PM. Homocysteine-Potential Novel Diagnostic Indicator of Health and Disease in Horses. Animals (Basel) 2023 Apr 11;13(8).
              doi: 10.3390/ani13081311pubmed: 37106874google scholar: lookup
            3. Nemec Svete A, Vovk T, Bohar Topolovec M, Kruljc P. Effects of Vitamin E and Coenzyme Q(10) Supplementation on Oxidative Stress Parameters in Untrained Leisure Horses Subjected to Acute Moderate Exercise. Antioxidants (Basel) 2021 Jun 3;10(6).
              doi: 10.3390/antiox10060908pubmed: 34205129google scholar: lookup
            4. Reiners JK, Hellmann N, Schmidt J, Kästner SBR. Odd haemoglobins in odd-toed ungulates: Impact of selected haemoglobin characteristics of the white rhinoceros (Ceratotherium simum) on the monitoring of the arterial oxygen saturation of haemoglobin. PLoS One 2019;14(12):e0226851.
              doi: 10.1371/journal.pone.0226851pubmed: 31887165google scholar: lookup
            5. Mönki J, Hewetson M, Virtala AM. Risk Factors for Equine Gastric Glandular Disease: A Case-Control Study in a Finnish Referral Hospital Population. J Vet Intern Med 2016 Jul;30(4):1270-5.
              doi: 10.1111/jvim.14370pubmed: 27461724google scholar: lookup
            6. Kaldur T, Kals J, Ööpik V, Zilmer M, Zilmer K, Eha J, Unt E. Effects of heat acclimation on changes in oxidative stress and inflammation caused by endurance capacity test in the heat. Oxid Med Cell Longev 2014;2014:107137.
              doi: 10.1155/2014/107137pubmed: 24895525google scholar: lookup
            7. Tsubone H, Hanafusa M, Endo M, Manabe N, Hiraga A, Ohmura H, Aida H. Effect of Treadmill Exercise and Hydrogen-rich Water Intake on Serum Oxidative and Anti-oxidative Metabolites in Serum of Thoroughbred Horses. J Equine Sci 2013;24(1):1-8.
              doi: 10.1294/jes.24.1pubmed: 24833996google scholar: lookup
            8. Minami Y, Kawai M, Migita TC, Hiraga A, Miyata H. Free radical formation after intensive exercise in thoroughbred skeletal muscles. J Equine Sci 2011;22(2):21-8.
              doi: 10.1294/jes.22.21pubmed: 24833984google scholar: lookup
            9. Kinnunen S, Atalay M, Hyyppä S, Lehmuskero A, Hänninen O, Oksala N. Effects of prolonged exercise on oxidative stress and antioxidant defense in endurance horse. J Sports Sci Med 2005 Dec;4(4):415-21.
              pubmed: 24501555
            10. Lamprecht ED, Williams CA. Biomarkers of antioxidant status, inflammation, and cartilage metabolism are affected by acute intense exercise but not superoxide dismutase supplementation in horses. Oxid Med Cell Longev 2012;2012:920932.
              doi: 10.1155/2012/920932pubmed: 22919442google scholar: lookup
            11. Williams CA, Burk AO. Antioxidant status in elite three-day event horses during competition. Oxid Med Cell Longev 2012;2012:572090.
              doi: 10.1155/2012/572090pubmed: 22792415google scholar: lookup
            12. el-Ashker MR. Acute kidney injury mediated by oxidative stress in Egyptian horses with exertional rhabdomyolysis. Vet Res Commun 2011 Jun;35(5):311-20.
              doi: 10.1007/s11259-011-9475-9pubmed: 21461642google scholar: lookup
            13. Choi EY, Jang JY, Cho YO. Coffee intake can promote activity of antioxidant enzymes with increasing MDA level and decreasing HDL-cholesterol in physically trained rats. Nutr Res Pract 2010 Aug;4(4):283-9.
              doi: 10.4162/nrp.2010.4.4.283pubmed: 20827343google scholar: lookup
            14. Kinnunen S, Hyyppä S, Lehmuskero A, Oksala N, Mäenpää P, Hänninen O, Atalay M. Oxygen radical absorbance capacity (ORAC) and exercise-induced oxidative stress in trotters. Eur J Appl Physiol 2005 Dec;95(5-6):550-6.
              doi: 10.1007/s00421-005-0034-3pubmed: 16136323google scholar: lookup
            15. Xiao DS, Ho KP, Qian ZM. Nitric oxide inhibition decreases bleomycin-detectable iron in spleen, bone marrow cells and heart but not in liver in exercise rats. Mol Cell Biochem 2004 May;260(1-2):31-7.
              doi: 10.1023/b:mcbi.0000026048.93795.03pubmed: 15228083google scholar: lookup
            16. 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
            17. Maturana M, Castillejos L, Jose-Cunilleras E, Montserrat-Malagarriga M, Alcaraz J, García J, Martín-Orúe SM. Effects of Blueberry Consumption on Preference, Digestibility, and Oxidative Balance in Dogs. Animals (Basel) 2025 May 21;15(10).
              doi: 10.3390/ani15101502pubmed: 40427378google scholar: lookup
            18. Johansson L, Ringmark S, Bergquist J, Skiöldebrand E, Widgren A, Jansson A. A proteomics perspective on 2 years of high-intensity training in horses: a pilot study. Sci Rep 2024 Oct 10;14(1):23684.
              doi: 10.1038/s41598-024-75266-8pubmed: 39390056google scholar: lookup
            19. Lashkari S, Beblein C, Christensen JW, Jensen SK. The effect of the fat to starch ratio in young horses' diet on plasma metabolites, muscle endurance and fear responses. J Anim Physiol Anim Nutr (Berl) 2025 Jan;109(1):113-123.
              doi: 10.1111/jpn.14037pubmed: 39163118google scholar: lookup
            20. Zhang X, Geng A, Cao D, Dugarjaviin M. Identification of mulberry leaf flavonoids and evaluating their protective effects on H(2)O(2)-induced oxidative damage in equine skeletal muscle satellite cells. Front Mol Biosci 2024;11:1353387.
              doi: 10.3389/fmolb.2024.1353387pubmed: 38650596google scholar: lookup
            Subscribe to our newsletter
            Join 99,344 horse owners like you who receive our email updates on horse health and nutrition.