Journal of Endocrinological Investigation

, Volume 31, Issue 7, pp 587–591 | Cite as

Exercise and circulating Cortisol levels: The intensity threshold effect

  • E. E. Hill
  • E. Zack
  • C. Battaglini
  • M. Viru
  • A. Viru
  • A. C. HackneyEmail author
Rapid Communication


This study examined the influence of exercise intensity upon the cortisol response of the hypothalamic-pituitaryadrenal (HPA) axis. Specifically, we examined exercise at intensities of 40, 60, and 80% maximal oxygen uptake (VO2max) in an attempt to determine the intensity necessary to provoke an increase in circulating cortisol. Twelve active moderately trained men performed 30 min of exercise at intensities of 40, 60, and 80% of their VO2max, as well as a 30-min resting-control session involving no exercise on separate days. Confounding factors such as time of day — circadian rhythms, prior diet — activity patterns, psychological stress, and levels of exercise training were controlled. Cortisol and ACTH were assessed in blood collected immediately before (pre-) and after (post-) each experimental session. Statistical analysis involved repeated measures analysis of variance and Tukey posthoc testing. The percent change in cortisol from pre- to post-sampling at each session was: resting-control, 40, 60, and 80% sessions (mean±SD) =−6.6±3.5%, +5.7±11.0%, +39.9±11.8%, and +83.1±18.5%, respectively. The 60% and 80% intensity magnitude of change was significantly greater than in the other sessions, as well as from one to another. The ACTH responses mirrored those of cortisol, but only the 80% exercise provoked a significant (p<0.05) increase pre- to post-exercise. The calculated changes in plasma volume for the resting-control, 40%, 60%, and 80% sessions were: +2.2±3.0%, −9.9±5.0%, −15.6±3.5%, and −17.2±3.3%, respectively. Collectively, the cortisol findings support the view that moderate to high intensity exercise provokes increases in circulating cortisol levels. These increases seem due to a combination of hemoconcentration and HPA axis stimulus (ACTH). In contrast, low intensity exercise (40%) does not result in significant increases in cortisol levels, but, once corrections for plasma volume reduction occurred and circadian factors were examined, low intensity exercise actually resulted in a reduction in circulating cortisol levels.


Endocrine physical activity stress hormones 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Hackney AC. Stress and the neuroendocrine system: the role of exercise as a stressor and modifier of stress. Expert Rev Endocrinol Metab 2006, 1: 783–92.PubMedCentralPubMedCrossRefGoogle Scholar
  2. 2.
    Wittert G, Livesey JH, Espiner EA, Donald RA. Adaptation of the hypothalamopituitary adrenal axis to chronic exercise stress in humans. Med Sci Sports Exerc 1996, 28: 1015–9.PubMedCrossRefGoogle Scholar
  3. 3.
    Davies CT, Few JD. Effects of exercise on adrenocortical function. J Appl Physiol 1973, 35: 887–91.PubMedGoogle Scholar
  4. 4.
    McMurray RG, Hackney AC. Endocrine responses to exercise and training. In: Garrett WE, Kirkendall DT, eds. Exercise and sport science. Philadelphia: Lippincott Williams & Wilkins 2000, 135–61.Google Scholar
  5. 5.
    Viru A, Viru M. Cortisol — Essential adaptation hormone in exercise. Int J Sports Med 2004, 25: 461–4.PubMedCrossRefGoogle Scholar
  6. 6.
    Widmaier EP. Metabolic feedback in mammalian endocrine systems. Horm Metab Res 1992, 24: 147–53.PubMedCrossRefGoogle Scholar
  7. 7.
    Viru A. Plasma hormones and physical exercise. Int J Sports Med 1992, 13: 201–9.PubMedCrossRefGoogle Scholar
  8. 8.
    Thuma JR, Gilders R, Verdun M, Loucks AB. Circadian rhythm of cortisol confounds cortisol responses to exercise: implications for future research. J Appl Physiol 1995, 78: 1657–64.PubMedGoogle Scholar
  9. 9.
    Duclos M, Corcuff JB, Rashedi M, Fougere V, Manier G. Trained versus untrained men: different immediate post-exercise responses of pituitary adrenal axis: a preliminary study. Eur J Appl Physiol Occup Physiol 1997, 75: 343–50.PubMedCrossRefGoogle Scholar
  10. 10.
    Jacks DE, Sowash J, Anning J, McGloughlin T, Andres F. Effect of exercise at three exercise intensities on salivary cortisol. J Strength Cond Res 2002, 16: 286–9.PubMedGoogle Scholar
  11. 11.
    Jurimae J, Jurimae T, Purge P. Plasma testosterone and cortisol responses to prolonged sculling in male competitive rowers. J Sports Sci 2001, 19: 893–8.PubMedCrossRefGoogle Scholar
  12. 12.
    Golding LA, Myers C, Sinning WE. The Y’s Way to Physical Fitness. (2nd ed) Champaign, IL: Human Kinetics, 1982.Google Scholar
  13. 13.
    Bouchard C, Shepard RJ, Stephens T, Sutton JR, McPherson BD, eds. Exercise, Fitness and Health: A Consensus of Current Knowledge. Champaign, IL: Human Kinetics Publishers, 1990.Google Scholar
  14. 14.
    Kellmann M, Kallus KW. Recovery-stress questionnaire for athletes. Champaign IL: Human Kinetics Publsihers, 2001.Google Scholar
  15. 15.
    American College of Sports Medicine’s Guidelines for Exercise Testing and Prescription (6th ed). Baltimore, MD: Williams & Wilkins, 2000.Google Scholar
  16. 16.
    Dill DB, Costill DL. Calculation and percentages in volumes of blood, plasma, and red cells in dehydration. J Appl Physiol 1974, 37: 247–8.PubMedGoogle Scholar
  17. 17.
    Hainline A. Hemoglobin. In: Selingson D ed. Standard Methods of Clinical Chemistry. vol. 2. New York: Academic Press 1958, 49.Google Scholar
  18. 18.
    Bloom SR, Johnson RH, Park DM, Rennie MJ, Sulaiman WR. Differences in the metabolic and hormonal response to exercise between racing cyclists and untrained individuals. J Physiol 1976, 258: 1–18.PubMedCentralPubMedGoogle Scholar
  19. 19.
    Luger A, Deuster PA, Kyle SB, et al. Acute hypothalamic-pituitary-adrenal responses to the stress of treadmill exercise: physiologic adaptations to physical training. N Engl J Med 1987, 316: 1309–15.PubMedCrossRefGoogle Scholar
  20. 20.
    Rudolph DL, McAuley E. Cortisol and affective responses to exercise. J Sports Sci 1998, 16: 121–8.PubMedCrossRefGoogle Scholar
  21. 21.
    Viru AM, Hackney AC, Välja E, Karelson K, Janson T, Viru M. Influence of prolonged continuous exercise on hormone responses to subsequent exercise in humans. Eur J Appl Physiol 2001, 85: 578–85.PubMedCrossRefGoogle Scholar
  22. 22.
    Daly W, Seegers C, Timmerman S, Hackney AC. Peak cortisol response to exhausting exercise: effects of blood sampling schedule. Medicina Sportiva 2004, 8: 17–20.Google Scholar

Copyright information

© Italian Society of Endocrinology (SIE) 2008

Authors and Affiliations

  • E. E. Hill
    • 1
  • E. Zack
    • 1
  • C. Battaglini
    • 1
  • M. Viru
    • 2
  • A. Viru
    • 2
  • A. C. Hackney
    • 1
    Email author
  1. 1.Endocrine Section, Applied Physiology Laboratory, Department of Exercise & Sport ScienceUniversity of North CarolinaChapel HillUSA
  2. 2.Institute of Exercise Biology and PhysiotherapyTartu UniversityTartuEstonia

Personalised recommendations