title: Does a 20-week aerobic exercise training programme increase our capabilities to buffer real-life stressors? A randomized, controlled trial using ambulatory assessment.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Institute of Sports and Sports Science, Karlsruhe Institute of Technology, Engler-Bunte-Ring 15, 76131, Karlsruhe, Germany. birte.haaren@kit.edu.
authors.forename: Birte
authors.initials: B
authors.lastname: von Haaren
authors.affiliation: , Fritz-Erler-Str. 1-3, 76131, Karlsruhe, Germany.
authors.forename: Joerg
authors.initials: J
authors.lastname: Ottenbacher
authors.affiliation: , 76199, Karlsruhe, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Muenz
authors.affiliation: Institute of Sports and Sports Science, Karlsruhe Institute of Technology, Engler-Bunte-Ring 15, 76131, Karlsruhe, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Neumann
authors.affiliation: Institute of Sports and Sports Science, Karlsruhe Institute of Technology, Engler-Bunte-Ring 15, 76131, Karlsruhe, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Boes
authors.affiliation: Institute of Sports and Sports Science, Karlsruhe Institute of Technology, Engler-Bunte-Ring 15, 76131, Karlsruhe, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Ebner-Priemer
mesh_terms: D015444:Exercise; D006339:Heart Rate; D006801:Humans; D008297:Male; D010101:Oxygen Consumption; D013315:Stress, Psychological / Q000517:prevention & control*; D055815:Young Adult
keywords: Aerobic exercise; Ambulatory assessment; Cross-stressor adaptation hypothesis; Heart rate variability; Psychological stress; Randomized controlled trial; Real life