Run training versus cross-training: effect of increased training on circulating leukocyte subsets

Med Sci Sports Exerc. 1995 Mar;27(3):355-62.


The purpose of this study was to determine the effects of increased training via cross-training (run + cycle) and run training on circulating leukocyte subsets. Male runners (N = 11) participated in two randomly assigned increased training (IT) periods after 30 d of normal training (NT). Each IT began after a 14 d period of reduced training (80% of NT) followed by 10 d of IT (200% of NT). During IT, the subjects ran in the afternoon for 10 d (100% NT) and performed 8 additional training sessions in the morning (100% NT) on a treadmill (ITRT) or a bicycle ergometer (ITCT). Blood samples were obtained before (D0), on day 5(D5) and after 10 d (D11) of ITRT and ITCT. A significant increase in the CD4+/CD8+ ratio occurred at D5 compared with D0 and D11. The CD4+/CD8+ ratio was significantly lower during ITRT compared with ITCT at D11. The number of circulating CD3+, CD4+, and CD8+ cells were significantly reduced at D11 compared with D0. In conclusion, 10 d of IT resulted in a significant reduction in the number of circulating T cells independent of the training mode and a reduction in the CD4+/CD8+ ratio for ITRT but not for ITCT.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Bicycling / education
  • Bicycling / physiology*
  • CD4 Lymphocyte Count
  • CD4-CD8 Ratio
  • CD4-Positive T-Lymphocytes / cytology
  • CD8-Positive T-Lymphocytes / cytology
  • Creatine Kinase / blood
  • Humans
  • Killer Cells, Natural / cytology
  • Leukocyte Count
  • Leukocytes / cytology
  • Lymphocyte Count
  • Male
  • Physical Education and Training
  • Running / education
  • Running / physiology*
  • T-Lymphocyte Subsets / cytology*
  • T-Lymphocytes / cytology


  • Creatine Kinase