HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS REGISTER		Author Keyword(s) Vol Page [Advanced]

This Article Full Text Full Text (PDF) All Versions of this Article: bjsm.2007.035535v1 bjsm.2007.035535v2 bjsm.2007.035535v3 42/2/116    most recent Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this link to a friend Similar articles in this journal Similar articles in PubMed Add article to my folders Download to citation manager Request Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Kraemer, W J Articles by Evans, D S Search for Related Content PubMed PubMed Citation Articles by Kraemer, W J Articles by Evans, D S Topic Collections Relevant Article

Hormonal responses to a 160-km race across frozen Alaska

¹ Human Performance Laboratory, University of Connecticut, Storrs, Connecticut, USA
² McDaniel College, Westminster, Maryland, USA
³ Gettysburg College, Gettysburg, Philadelphia, USA
⁴ Sitka Medical Center, Sitka, Arkansas, USA
⁵ Elon University, Elon, North Carolina, USA
⁶ Alaska Native Medical Center, Anchorage, Alaska, USA

Correspondence to:
Professor W J Kraemer, PhD, University of Connecticut, Human Performance Laboratory, Storrs, Connecticut 06269-1110, USA; william.kraemer{at}uconn.edu

Background: Severe physical and environmental stress seems to have a suppressive effect on the hypothalamic–pituitary–gonadal (HPG) axis in men. Examining hormonal responses to an extreme 160-km competition across frozen Alaska provides a unique opportunity to study this intense stress.

Objective: To examine hormonal responses to an ultra-endurance race.

Methods: Blood samples were obtained from 16 men before and after racing and analyzed for testosterone, interleukin-6 (IL-6), growth hormone (GH) and cortisol. Six subjects (mean (SD) age 42 (7) years; body mass 78.9 (7.1) kg; height 1.78 (0.05) m raced by bicycle (cyclists) and 10 subjects (age 35 (9) years; body mass 77.9 (10.6) kg; height, 1.82 (0.05) m) raced by foot (runners). Mean (SD) finish times were 21.83 (6.27) and 33.98 (6.12) h, respectively.

Results: In cyclists there were significant (p0.05) mean (SD) pre-race to post-race increases in cortisol (254.83 (135.26) to 535.99 (232.22) nmol/l), GH (0.12 (0.23) to 3.21 (3.33) µg/ml) and IL-6 (2.36 (0.42) to 10.15 (3.28) pg/ml), and a significant decrease in testosterone (13.81 (3.19) to 5.59 (3.74) nmol/l). Similarly, in runners there were significant pre-race to post-race increases in cortisol (142.09 (50.74) to 452.21 (163.40) ng/ml), GH (0.12 (0.23) to 3.21 (3.33) µg/ml) and IL-6 (2.42 (0.68) to 12.25 (1.78) pg/ml), and a significant decrease in testosterone (12.32 (4.47) to 6.96 (3.19) nmol/l). There were no significant differences in the hormonal levels between cyclists and runners (p>0.05).

Conclusions: These data suggest a suppression of the hypopituitary–gonadal axis potentially mediated by amplification of adrenal stress responses to such an ultra-endurance race in environmentally stressful conditions.

Keywords: ultra endurance race; testosterone; growth hormone; cortisol

Relevant Article

Commentary on "Hormonal responses to a 160-km race across frozen Alaska"

Lee E Brown
Br. J. Sports Med. 2008 42: 120. [Extract] [Full Text] [PDF]