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- Gerber, M, et al.
(författare)
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Concerns regarding hair cortisol as a biomarker of chronic stress in exercise and sport science
- 2012
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Ingår i: Journal of Sports Science and Medicine. - 1303-2968. ; 11, s. 571-581
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Forskningsöversikt (refereegranskat)abstract
- Hair cortisol has the potential to fill the methodological void of long-term cortisol assessment while becoming a widely accepted measure in biopsychology. This review critically examines the applicability and relevance of hair cortisol measurement specifically within the field of exercise and sport science. Current measures of the HPA axis only cover a brief time period, whereas hair cortisol is a unique, non-invasive means to capture long-term cortisol secretion. Studies have shown that individuals who have elevated cortisol secretion (e.g. due to diseases associated with a disturbed activation of the HPA axis or exposure to stressful life events) reveal increased hair cortisol. By contrast, only weak correlations exist between hair cortisol and perceived stress, and the direction of the relationship between hair cortisol levels and mental disorders is unclear. Acute exercise, however, results in increased levels of cortisol that eventually is reflected in higher levels of cortisol in hair samples and studies have shown that exercise intensity is related to hair cortisol level. Thus, elevated hair cortisol levels found among regular exercisers are not necessarily pathological. Thus, one should practice caution when associating athletes’ elevated hair cortisol with poor mental health or disease. Hair cortisol analysis can contribute to a more complete understanding of how long-term cortisol elevation mediates stress-related effects on the health and performance of recreational exercisers and elite athletes. Nevertheless, it is crucial for exercise and sport scientists to consider whether their research questions can be adequately addressed, given that regular intense exercise results in substantially augmented hair cortisol levels.
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- Gerber, M, et al.
(författare)
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Longitudinal relationships between perceived stress, exercise self-regulation, and exercise involvement among physically active adolescents
- 2015
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Ingår i: Journal of Sports Sciences. - : Informa UK Limited. - 0264-0414 .- 1466-447X. ; 33:4, s. 369-380
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Tidskriftsartikel (refereegranskat)abstract
- Stress exposure may undermine exercisers’ capability to self-regulate their exercise behaviour. This longitudinal study examined the interplay between perceived stress, exercise self-regulation (assessment of action and coping planning) and participation in vigorous exercise in vocational students. Moreover, this study examined whether high exercise self-regulation moderates the assumed negative relationship between stress and exercise. A sample of 580 physically active vocational students (x ± s 17.8 ± 1.3 years, 33.8% girls) was assessed. All participants completed two identical validated questionnaires assessing stress, exercise self-regulation and exercise with a span of 10 months in between survey completion periods. The cross-sectional analyses show that high exercise self-regulation attenuated the assumed negative relationship between stress and exercise. In the longitudinal analyses, however, only a non-significant trend was found. Significant longitudinal relationships existed between exercise self-regulation and exercise involvement. Latent difference score models revealed that a drop in the exercise self-regulation was associated with a concurrent decrease in exercise participation. Cross-lagged panel analyses showed that high exercise self-regulation levels positively predicted exercise behaviour, but an inverse relationship was not supported. The findings suggested that higher exercise self-regulation levels were positively associated with future exercise involvement in currently active adolescents. While partial support was found that exercise selfregulation moderated the influence of stress on exercise, the findings demonstrated that higher exercise self-regulation levels had a positive impact on future exercise involvement in already active individuals.
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- Gerber, M., et al.
(författare)
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Objectively assessed physical activity is associated with increased hair cortisol content in young adults
- 2013
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Ingår i: Stress-the International Journal on the Biology of Stress. - : Informa UK Limited. - 1025-3890. ; 16:6, s. 593-599
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Tidskriftsartikel (refereegranskat)abstract
- Assessing long-term cortisol secretion presents difficulties when cortisol measurement is carried out by saliva, plasma and urine analyses. Hair cortisol has gained increased interest as an alternative biological marker. So far, one study has been published studying hair cortisol in endurance athletes, showing higher levels compared to controls. Using accelerometer data in the present study, we cross-sectionally explored the relationship between moderate physical activity (MPA) and vigorous physical activity (VPA) levels and hair cortisol concentrations after taking into account age, gender, and perceived stress. Hair specimens were collected from 46 university students (20 males, 26 females, M-age +/- SD = 21.2 +/- 1.87 years). Participants provided information about their socio-demographic background and levels of perceived stress. Accelerometer data were collected to assess physical activity. Cortisol concentrations were measured in the first 3-cm hair segment nearest to the scalp. MPA was not correlated with hair cortisol content (r = -0.08). A significant correlation was found between VPA and hair cortisol (r = 0.34, p < 0.05). A regression analysis revealed that participants with higher VPA had elevated hair cortisol concentrations even after taking into account age, gender and perceived stress (beta = 0.33, p < 0.05, Delta R-2 = 0.106). This is the first study showing that objectively assessed VPA is associated with increased hair cortisol levels in young adults. As VPA can be regarded as a physical stressor, it seems imperative that researchers consider participants' levels of VPA if they examine the relationship between stress exposure, hair cortisol and health.
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