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.00562.2005. Epub 2005 Dec 15.


Leukocytosis following exercise is a well-described phenomenon of stress/inflammatory activation in healthy humans. We hypothesized that, despite this increase in circulating inflammatory cells, exercise would paradoxically induce expression of both pro- and anti-inflammatory cytokines and growth factors within these cells. To test this hypothesis, 11 healthy adult men, 18-30 yr old, performed a 30-min bout of heavy cycling exercise; blood sampling was at baseline, end-exercise, and 60 min into recovery. The percentage of leukocytes positive for intracellular cytokines and growth factors and mean fluorescence intensity was obtained by flow cytometry. Proinflammatory cytokines (IL-1alpha, IL-2, IFN-gamma, and TNF-alpha), a pleiotropic cytokine (IL-6), and anti-inflammatory cytokines and growth factors [IL-4, IL-10, growth hormone (GH), and IGF-I] were examined. Median fluorescence intensity was not affected by exercise; however, we found a number of significant changes (P < 0.05 by mixed linear model and modified t-test) in the numbers of circulating cells positive for particular mediators. The pattern of expression reflected both pro- and anti-inflammatory functions. In T-helper lymphocytes, TNF-alpha, but also IL-6, and IL-4 were significantly increased. In monocytes, both IFN-gamma and IL-4 increased. B-lymphocytes positive for GH and IGF-I increased significantly. GH-positive granulocytes also significantly increased. Collectively, these observations indicate that exercise primes an array of pro- and anti-inflammatory and growth factor expression within circulating leukocytes, perhaps preparing the organism to effectively respond to a variety of stressors imposed by exercise.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adolescent
  • Adult
  • Anti-Inflammatory Agents / metabolism*
  • Cytokines / metabolism*
  • Exercise / physiology*
  • Granulocytes / metabolism
  • Human Growth Hormone / metabolism
  • Humans
  • Inflammation Mediators / metabolism*
  • Insulin-Like Growth Factor I / metabolism
  • Intercellular Signaling Peptides and Proteins / metabolism*
  • Interleukins / metabolism
  • Leukocytes / metabolism*
  • Lymphocyte Count
  • Lymphocytes / metabolism
  • Male
  • Monocytes / metabolism
  • Tumor Necrosis Factor-alpha / metabolism


  • Anti-Inflammatory Agents
  • Cytokines
  • Inflammation Mediators
  • Intercellular Signaling Peptides and Proteins
  • Interleukins
  • Tumor Necrosis Factor-alpha
  • Human Growth Hormone
  • Insulin-Like Growth Factor I