Relationship Between Change In Core Temperature and Change In Cortisol and Tnfα During Exercise

Document Type

Article

Publication Date

10-1-2010

Journal / Book Title

Journal of Thermal Biology

Abstract

The combined thermal load created by exercise and a hot environment is associated with an exaggerated core temperature response. The elevated core temperature is believed to increase the total stress of the exercise. Increased stress during exercise has been associated with increased levels of cortisol. The association of cortisol with increased inflammatory responses following exercise in the heat is equivocal. Thus, the purpose of the current investigation was to explore the relationship between increases in rectal temperature (Tre) and TNFα and cortisol. To induce Tre changes, 8 male subjects (mean±SD, age=23.6±2yr, VO2max=52.8±3.7mL/kg/min, BMI=24.2±1.9) participated in two 40min trials of cycle ergometry at 65% of VO2peak immersed to chest level in cool (25°C) and warm (38.5°C) water. Tre was monitored throughout each trial, with blood samples taken immediately pre and post of each trial. Neither cortisol nor TNFα changed significantly during exercise in the cool water; however, in the warm trial, both cortisol and TNFα significantly increased (p<0.004). Concordance correlations (Rc) between Δcortisol and ΔTNFα indicated a strong but non-significant correlation (Rc=0.833, p=0.135). In conclusion, changes in core temperature may be impacting the relationship between exercise induced changes in cortisol and TNFα. Therefore, acute moderate-intensity exercise (40min or less) in warm water impacts the stress and inflammatory response. Understanding this is important because exercise load may need to be adjusted in warm and hot environments to avoid the negative effects of elevated stress and inflammation response.

DOI

10.1016/j.jtherbio.2010.07.003

This document is currently not available here.

Link to Publisher
Link at MSU

Share

COinS