European Journal of Applied Physiology and Occupational Physiology

, Volume 56, Issue 6, pp 628–632

Regulation of growth hormone during exercise by oxygen demand and availability

  • W. P. VanHelder
  • K. Casey
  • M. W. Radomski
Article

DOI: 10.1007/BF00424801

Cite this article as:
VanHelder, W.P., Casey, K. & Radomski, M.W. Europ. J. Appl. Physiol. (1987) 56: 628. doi:10.1007/BF00424801

Summary

Five normal men performed seven sets of seven squats at a load equal to 80% of their seven repetition maximum. Plasma growth hormone (GH) and lactate levels increased during and after the completion of the exercise. A significant (r=0.93, P<0.001) linear correlation was found between GH changes and the corresponding oxygen Demand/Availability (D/A) ratio expressed by \(\left[ {\int\limits_0^x {\dot V_{O_2 } } \cdot dt} \right] \cdot f\) (where f=[lactate at time x]/[lactate at time 0]). A retrospective examination of previously published data from our laboratory and others also demonstrated the existence of a significant correlation between changes in plasma GH levels and the D/A ratios over a wide variety of exercise; aerobic and anaerobic, continuous and intermittent, weight lifting and cycling, in both fit and unfit subjects under normoxic and hypoxic conditions. It is suggested that the balance between oxygen demand and availability may be an important regulator of GH secretion during exercise.

Key words

Growth hormoneLactic acidOxygen demandOxygen availabilityExercise

Copyright information

© Springer-Verlag 1987

Authors and Affiliations

  • W. P. VanHelder
    • 1
    • 2
  • K. Casey
    • 1
    • 2
  • M. W. Radomski
    • 1
    • 2
  1. 1.Department of Physiology, and the School of Physical and Health EducationUniversity of TorontoCanada
  2. 2.Defence and Civil Institute of Environmental MedicineCanada