Thyroid hormone levels during a 3-week professional road cycling competition

Aims: The aim of this investigation was to examine the thyroid hormone levels of professional cyclists during a 3-week stage competition (Vuelta a Espana 1998). Methods: The study population was made up of 16 male cyclists from two world-leading professional teams. Four blood samples were drawn (between 07:00 and 09:00 a.m.) from each participant before and at the end of the 1st, 2nd and 3rd weeks of competition. 3,5,3'(-Triiodothyronine (T(3)), free T(3) (FT(3)), thyroxine (T(4)), free T(4) (FT(4)) and thyroid-stimulating hormone (TSH) were determined in each blood sample by radioimmunoassay. Results: Serum T(4), FT(4) and FT(3) levels showed a significant increase (p < 0.05) by the last week of competition while concentrations of TSH and T(3) remained unchanged. Conclusion: In conclusion, 3 weeks of competition provokes changes in basal thyroid hormone concentrations in professional road cyclists.
© Copyright 2001 Hormone Research. Karger. All rights reserved.

Bibliographic Details
Subjects:
Notations:endurance sports biological and medical sciences
Published in:Hormone Research
Language:English
Published: 2001
Online Access:http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11910201&dopt=Abstract
Volume:56
Issue:5-6
Pages:159-164
Document types:article
Level:advanced