Advisor

Tidwell, Diane K.

Committee Member

Webb, Heather E.

Committee Member

Fountain, Brent J.

Committee Member

Smith, JohnEric William

Committee Member

Schilling, M. Wes

Other Advisors or Committee Members

Williams, Ronald D., Jr

Date of Degree

1-1-2015

Document Type

Dissertation - Open Access

Abstract

Chronic psychological and physiological stress is linked to a high prevalence of cardiovascular disease (CVD). Potentially dangerous cardiovascular responses (e.g., exacerbated cortisol production) can occur with high levels of stress and chronic hypercortisolemia is associated with CVD. The ingestion of carbohydrate (CHO) prior to physical stress may attenuate cortisol responses to stress. The purpose of this project was to investigate the potential effect of CHO ingestion on cortisol production and responses to concurrent stress challenges. Sixteen apparently healthy non-smoking men 21-30 years old participated in a randomized, cross-over, double blind, placebo controlled trial. Participants were tested on four separate sessions. In session 1, general procedures were explained, and participants provided written informed consent as well as a health history questionnaire. Anthropometric data were obtained and participants performed a VO2 peak test during session 2, as well as a 90 sec familiarization session with the mental stress challenges. During the third and fourth sessions, either a 6.6% CHO solution or non-CHO control beverage (water containing non-caloric ingredients tasting like the CHO beverage) was randomly assigned and orally ingested at 0.6g/kg body weight 15 min prior to performing a dual-concurrent-stress (DCS) challenge. The DCS procedure consisted of physical stress (i.e., exercise) combined with computerized mental stress tests of color word associations and arithmetic. Ten mL of blood were obtained at each blood draw: 70, 40, and 15 min prior to the start of exercise, immediately at onset of exercise, 10, 20, 30, and 35 min during exercise, and 15, 30, 45, and 60 min during a post exercise recovery period. There was a significant main effect for treatment regarding mean cortisol production, and the DCS challenge was effective at increasing anxiety and acting as an effective stressor. Mean cortisol production was consistently lower during and after DSC. This is a potential beneficial implication for individuals that work in high-stress conditions. These findings support a prevention based approach to address the high prevalence of CVD among individuals and others working in high-stress occupations such as firefighters.

URI

https://hdl.handle.net/11668/21076

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