Need another reason to work out? Aerobic Fitness Impacts Cortisol Responses to Concurrent Challenges

http://www.ncbi.nlm.nih.gov/pubmed/22935740

Med Sci Sports Exerc. 2012 Aug 29. [Epub ahead of print]

Aerobic Fitness Impacts Cortisol Responses to Concurrent Challenges.

Webb HE, Rosalky DS, Tangsilsat SE, McLeod KA, Acevedo EO, Wax B.

Source

1Mississippi State University, Mississippi State, Mississippi 2The University of New South Wales, Sydney, Australia 3Virginia Commonwealth University, Richmond, Virginia.

Abstract

Studies have demonstrated that a combination of mental and physical challenge can elicit exacerbated state anxiety, effort sense, and cortisol responses above that of a single stimulus. However, an analysis of the effects of aerobic fitness on the responses of cortisol to concurrent mental andphysical stress between below average and above average fitness individualshas not been conducted.

PURPOSE:

This study examined the effects of a combination of acute mental challenges and physical stress on psychological and cortisolresponses between eight individuals of below average fitness (Low-fit [LF], VO2max = 36.58 ± 3.36 mL/kg/min) and eight individuals of above average fitness(High-fit [HF], VO2max = 51.18 ± 2.09 mL/kg/min).

METHODS:

All participants completed two experimental conditions. An exercise-alone condition (EAC) consisted of cycling at 60% VO2max for 37 minutes, and a dual-challenge condition (DCC) that included concurrent participation in a mental challenge for 20 minutes whilst cycling.

RESULTS:

The DCC resulted in increases in state anxiety (p = .018), perceived overall workload (p = .001), and exacerbated cortisol responses (p= .04).Further, LF participants had a greater overall cortisol response in the DCC compared to the EAC(DCC = 346.83 ±226.92; EAC = -267.46 ± 132.32; t7=2.49, p=0.04), while HF participants demonstrated no difference between conditions(DCC = 38.91 ± 147.01; EAC = -324.60 ± 182.78; t7 = 1.68, p = 0.14).

DISCUSSION:

LF individuals seem to demonstrate unnecessary and unfavorable responses to the DCC compared to HF individuals, particularly concerning cortisol. The exacerbated cortisol responses in LF individuals have implications for harmful consequences such as increased risk of cardiovascular disease.