Physical versus psychosocial stress: effects on hormonal, autonomic, and psychological parameters in healthy young...

As a time-efficient training system, high intensity interval training (HIIT) is well known for several beneficial effects. However, the literature on the stress-generating effects of HIIT shows a research deficit. A standardized comparable stressor and different kinds of stress-parameters are needed for quantifying the results. The present study examined the hormonal, autonomic, and psychological stress outcomes of HIIT compared to a standardized psychosocial stressor and tested the cross-stressor-adaptation (CSA) hypothesis which implies a stress-buffering effect at a good fitness level. In a sample of 32 healthy young males (24.31 ± 3.35 years of age) stress was induced with a multiple Wingate (WG), as a HIIT all-out performance test, involving four 30 sec all-out exercise bouts. In addition, the Trier Social Stress Test (TSST), which consists of a mock job interview and mental arithmetic performance, was used for stress induction. Cortisol, heart rate variability (HRV), and stress-related questionnaires were assessed before, during, and after stress induction. Both the Wingate as well as the TSST led to a highly significant change in time and stressor for cortisol and HRV. Furthermore, a significantly higher delta during Wingate was identified. In part, the TSST had a significantly higher impact on the psychological measurements than the WG. In contrast to the literature, this study was not able to confirm the stress-buffering effect of the CSA hypothesis. These findings prove the stressful effect of HIIT. The prevention of negative health effects needs to be taken into consideration in sports training methods and programs as well as in stress-related research Lay summary   By using a well-estimated psychosocial stressor for comparison and several stress parameters, this study is able to show the strong stress-generating effect of high intensity interval training (HIIT). Interestingly, subjective stress perception differed from objective stress response. This research is an important step towards understanding stress-related disorders in elite sport and making recommendations for reducing autonomic as well as hormonal stress in high intensity sport.