Haaren, Birte; Ottenbacher, Joerg;
Muenz, Julia; Neumann, Rainer; Boes, Klaus; Ebner-Priemer, Ulrich.

European Journal of Applied Physiology, February 2016, Vol. 116 Issue:
Number 2 p383-394, 12p;

Abstract: The cross-stressor adaptation
hypothesis suggests that regular exercise leads to adaptations in the
stress response systems that induce decreased physiological responses
to psychological stressors. Even though an exercise intervention to
buffer the detrimental effects of psychological stressors on health
might be of utmost importance, empirical evidence is mixed. This may be
explained by the use of cross-sectional designs and non-personally
relevant stressors. Using a randomized controlled trial, we
hypothesized that a 20-week aerobic exercise training does reduce
physiological stress responses to psychological real-life stressors in
sedentary students.   Sixty-one students were  randomized to either a
control group or an exercise training group. The
academic examination period (end of the semester) served as a real-life
stressor. We used ambulatory assessment methods to assess physiological
stress reactivity of the autonomic nervous system (heart rate
variability: LF/HF, RMSSD), physical activity and perceived stress
during 2 days of everyday life and multilevel models for data analyses.
Aerobic capacity (VO2max) was assessed pre- and post-intervention via
cardiopulmonary exercise testing to analyze the effectiveness of the
intervention.   During real-life stressors, the exercise training group
showed significantly reduced LF/HF (β= −0.15,
t= −2.59, p= .01) and increased RMSSD (β= 0.15, t= 2.34, p= .02)
compared to the control group.
Using a randomized
controlled trial and a real-life stressor, we could show that exercise
appears to be a useful preventive strategy to buffer the effects of
stress on the autonomic nervous system, which might result into
detrimental health outcomes.