Endocrine

, Volume 24, Issue 1, pp 93–98

Ghrelin and other glucoregulatory hormone responses to eccentric and concentric muscle contractions

  • R. R. Kraemer
  • R. J. Durand
  • D. B. Hollander
  • J. L. Tryniecki
  • E. P. Hebert
  • V. D. Castracane
Original Articles

DOI: 10.1385/ENDO:24:1:093

Cite this article as:
Kraemer, R.R., Durand, R.J., Hollander, D.B. et al. Endocr (2004) 24: 93. doi:10.1385/ENDO:24:1:093

Abstract

Objective: Heavy resistance exercise increases growth hormone (GH) and blood glucose levels. Ghrelin is an endogenous ligand for the GH secretagory receptor that stimulates growth hormone release. Circulating ghrelin levels are suppressed by insulin and glucose. The study was conducted to determine effects of concentric (CON) and eccentric (ECC) muscle actions at the same absolute workload on circulating ghrelin and glucose as well as related glucoregulatory peptides.

Methods: Ten-RM loads for bench press, leg extension, military press, and leg curl were obtained from nine males, mean age 25.±1.2 yr and body fat 17.2±1.6%. Subjects then completed two experimental trials of either CON or ECC contractions at the same absolute workload. Subjects performed four sets of 12 repetitions for each exercise at 80% of a 10-RM with 90 s rest periods. A pulley system or steel levers were positioned on each machine to raise or lower the weight so only CON or ECC contractions were performed. Pre-, post-, and 15-min post-exercise blood samples were collected.

Results: Ghrelin did not increase in response to either muscle action and actually declined during the CON trial. Glucose and insulin increased regardless of the form of muscle action, but amylin and C-peptide did not change.

Conclusions: Data indicate that ghrelin does not contribute to moderate resistance exercise-induced increases in growth hormone, whether from CON or ECC muscle actions. Results suggest that with a moderate loading protocol both CON and ECC muscle actions performed at the same absolute workload elevate glucose and insulin concentrations, but are not related to post-CON exercise ghrelin suppression.

Key Words

Ghrelinglucoseinsulinamylinresistance exercise

Copyright information

© Humana Press Inc 2004

Authors and Affiliations

  • R. R. Kraemer
    • 1
  • R. J. Durand
    • 2
  • D. B. Hollander
    • 1
  • J. L. Tryniecki
    • 1
  • E. P. Hebert
    • 1
  • V. D. Castracane
    • 3
  1. 1.Department of Kinesiology and Health StudiesSoutheastern Louisiana University, SLU10845Hammond
  2. 2.Pennington Biomedical Research Center, Health and Fitness CenterBaton Rouge
  3. 3.V Daniel Castracane, Department of Obstetrics and GynecologyTexas Tech University Health Sciences CenterAmarillo