QUT ePrints

The effects of increased endurance training load on biomarkers of heat intolerance during intense exercise in the heat

Lim, Chin Leong, Pyne, David, Horn, Peggy, Katz, Amelia, Saunders, Philo, Peake, Jonathan, Suzuki, Katsuhiko, Wilson, Gary, & Mackinnon, Laurel (2009) The effects of increased endurance training load on biomarkers of heat intolerance during intense exercise in the heat. Applied Physiology, Nutrition and Metabolism, 34(4), pp. 616-624.

View at publisher

Abstract

The effects of increased training (IT) load on plasma concentrations of lipopolysaccharides (LPS), proinflammatory cytokines, and anti-LPS antibodies during exercise in the heat were investigated in 18 male runners, who performed 14 days of normal training (NT) or 14 days of 20% IT load in 2 equal groups. Before (trial 1) and after (trial 2) the training intervention, all subjects ran at 70% maximum oxygen uptake on a treadmill under hot (35 degrees C) and humid (similar to 40%) conditions, until core temperature reached 39.5 degrees C or volitional exhaustion. Venous blood samples were drawn before, after, and 1.5 h after exercise. Plasma LPS concentration after exercise increased by 71% (trial 1, p < 0.05) and 21% (trial 2) in the NT group and by 92% (trial 1, p < 0.01) and 199% (trial 2, p < 0.01) in the IT group.

Postintervention plasma LPS concentration was 35% lower before exercise (p < 0.05) and 47% lower during recovery (p < 0.01) in the IT than in the NT group. Anti-LPS IgM concentration during recovery was 35% lower in the IT than in the NT group (p < 0.05). Plasma interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha concentrations after exercise (IL-6, 3-7 times, p < 0.01, and TNF-alpha, 33%, p < 0.01) and during recovery (IL-6, 2-4 times, p < 0.05, and TNF-alpha, 30%, p < 0.01) were higher than at rest within each group. These data suggest that a short-term tolerable increase in training load may protect against developing endotoxemia during exercise in the heat.

Impact and interest:

7 citations in Scopus
Search Google Scholar™
7 citations in Web of Science®

Citation countsare sourced monthly from Scopus and Web of Science® citation databases.

These databases contain citations from different subsets of available publications and different time periods and thus the citation count from each is usually different. Some works are not in either database and no count is displayed. Scopus includes citations from articles published in 1996 onwards, and Web of Science® generally from 1980 onwards.

Citations counts from the Google Scholar™ indexing service can be viewed at the linked Google Scholar™ search.

ID Code: 54301
Item Type: Journal Article
Keywords: exercise, heat stress, overload training, inflammation, endotoxemia
DOI: 10.1139/H09-021
ISSN: 1715-5312
Subjects: Australian and New Zealand Standard Research Classification > MEDICAL AND HEALTH SCIENCES (110000) > HUMAN MOVEMENT AND SPORTS SCIENCE (110600) > Exercise Physiology (110602)
Divisions: Current > QUT Faculties and Divisions > Faculty of Health
Deposited On: 25 Oct 2012 13:34
Last Modified: 29 Oct 2012 09:55

Export: EndNote | Dublin Core | BibTeX

Repository Staff Only: item control page