Longitudinal associations between cardiorespiratory fitness and stress-related exhaustion, depression, anxiety and sleep disturbances

Abstract

BackgroundIn the last few years, so-called “common mental disorders”, including adjustment disorder and stress-related exhaustion, have outrivalled musculoskeletal disorders as being the leading cause of long-term sick leave in Sweden. Cardiorespiratory fitness level defined as “the maximal amount of physiological work that an individual can do as measured by oxygen consumption” has in many studies shown to reduce the risk of several life-style related diseases and moreover to improve mood, well-being and physical performance. The aim of the present study was to investigate, longitudinal associations between cardiorespiratory fitness and self-reported physical activity levels and the severity of symptoms connected to stress-related exhaustion, depression, anxiety, and sleep disturbances among women clinically diagnosed with stress-related exhaustion disorder (ED).MethodsThe study was that of a longitudinal cohort study consisting of women (n = 88) diagnosed with stress-related ED in a specialist clinic in Gothenburg, Sweden. Cardiorespiratory fitness was measured with the Åstrand indirect test of maximal oxygen uptake (VO2max) and subjective measures of physical activity levels were rated on 4-graded physical activity scale. To measure and follow symptoms of ED over time the SMBQ-questionnaire (Shirom Melamed Burnout Questionnaire) was used. The Hospital Anxiety and Depression Scale (HADS) was used to measure depression and anxiety. A proxy variable for capturing overall disturbed sleep used to measure sleep. Longitudinal associations for continuous outcome variables and the dichotomous variable sleep were analysed using mixed- effects regression models with random intercepts. Regression coefficients along with the 95% confidence interval (CI) are presented as measures of association. Both exposures and the outcome were measured simultaneously over six waves (T1–T6).ResultsThe results showed statistically significant associations between level of fitness and reduced symptoms of stress-related exhaustion over time. Best improvements over time were seen in patients having a medium cardiorespiratory fitness level. No associations could be found between cardiorespiratory fitness level over time and anxiety, depression or sleep disturbances.ConclusionHaving medium cardiorespiratory fitness was positivity associated with a more sustained reduction in symptoms of ED overtime compared to those having low or high cardiorespiratory fitness levels. The clinical implication following this result is that an individual recommendation based on a medium level of physical activity in line with the recommendations from ACSM (American College of Sports Medicine) is preferable compared to recommendations including more vigorous physical activity in order to restore and sustainably reduce symptoms of exhaustion disorder over time.

Muscular and cardiorespiratory fitness are associated with health-related quality of life among young adult men

“…The birth cohort study on young adults at the age of 31 by Suija et al [25] showed that only muscular fitness was negatively associated with depressive symptoms in both sexes. Similar findings were also found in a longitudinal study by Lindegård et al [27] who found no association between cardiorespiratory fitness level and anxiety, depression or sleep disturbances in women diagnosed with stress-related exhaustion disorders. However, they did find a positive association between the level of cardiorespiratory fitness and reduced symptoms of stress-related exhaustion over time.…”

“…In young adulthood, low muscular strength has been found to be an emerging risk factor for major causes of death, such as suicide and cardiovascular diseases [21] and to be associated with higher levels of stress [24], lower level of mental well-being [22,24] and increased health-risk behaviour [22]. Similarly, reduced cardiorespiratory fitness has been found to associate with higher levels of depressive symptoms [25,26], stress [24] and stress-related exhaustion [27] as well as lower levels of mental well-being [24]. In terms of HRQoL, a positive association with physical fitness has been found in the samples of middle aged [11] and young men [9,10] from the perspective of cardiorespiratory and muscular fitness.…”

The Effect of Muscular Strength on Depression Symptoms in Adults: A Systematic Review and Meta-Analysis

“…Physical fitness is a multi-component construct, including cardiorespiratory fitness, muscular fitness, flexibility, balance, and speed. There is longitudinal evidence that cardiorespiratory fitness, a component of physical fitness, is related to depression, preventing it or having a treatment effect [6,7]. Muscular strength is a component of muscular fitness that defines how much strength an individual can voluntarily produce by contracting muscles, and has been associated with a lower risk of mortality in the adult population [8].…”

The Association Between Cardiorespiratory Fitness and Reported Physical Activity With Sleep Quality in Apparently Healthy Adults: A Cross-Sectional Study

“…Limited studies were investigating the association between CRF and other parameters related to the quality of sleep. A longitudinal study reported no association between CRF and sleep disturbances in (n=88) females diagnosed with stress-related exhaustive disorders [12]. On the contrary, a cross-sectional study reported that poor CRF was weakly associated with poor sleep quality among (n=552) adolescents girls [9].…”

“…Studies investigating the relationship between CRF with sleep quality are scarce. In a longitudinal study, CRF was not associated with sleep disturbances among women diagnosed with stress-related exhaustion disorder [12]. The association between CRF and sleep quality was reported among apparently healthy adolescents' girls [9].…”