Browsing by Subject "heart rate variability"

Now showing 1 - 2 of 2
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    Cardiovascular Health and Occupational Stress in Police Officers
    (2018-05) Betker, Morgan
    Police officers have a higher incidence of disease and mortality rates when compared to the general population. Few studies have examined the link between lifestyle factors, occupational stressors and physiological dysfunction and how these factors lead to disease progression among police officers. The purpose of this dissertation was to examine the impact of physical fitness, lifestyle and occupational factors, perceived stressors, and sleep quality on various aspects of police officer physical, physiological and psychological health. Specifically, police officers (n = 116) completed several testing methods, both in the lab and field-based settings, assessing physical, physiological and psychological health. The first aim was to understand the influence of lifestyle and occupational factors on cardiovascular fitness and autonomic nervous system function among police officers. Not surprisingly, results indicated that officers who engage in regular exercise and have a low body fat also have higher aerobic fitness. There was not a significant relationship between heart rate variability indices and other lifestyle or occupational factors. The secondary aim was to examine the effect of perceived work stress on physiological biomarker expression for cardiovascular health. Results indicated that high scores on the Police Occupational Stress Survey (POSS) were related to higher pro-inflammatory cytokines (C-reactive protein (CRP) and tumor necrosis factor alpha (TNFα)). Finally, the purpose of the third aim was to examine the effect of sleep quality and shift-work on physiological biomarker expression in association with cardiovascular health. Contrary to what was hypothesized, day-time officers had higher levels of cortisol and total cholesterol expression than middle- or night-shift officers. In conclusion, poor lifestyle choices, unmanaged stressors, and constantly rotating shift schedules may contribute to increased allostatic load which can contribute to early, all-cause mortality among police officers. Future studies are needed that further examine cardiovascular health, sources of perceived stress, and sleep disturbances. Additionally, future research should examine the efficacy of interventions that address psychosocial factors and cardiovascular fitness among police officers.
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    Comparing the impact of the moderate and heavy exercise domains on autonomic control, circulating cortisol, and next-day endurance performance in trained runners
    (2022-05) Foreman, Nicholas
    This thesis examines the impact of exercise in the moderate and heavy domainson aspects of the hypothalamic-pituitary-adrenocortical axis, cardiac autonomic control, and subsequent high-intensity and maximal endurance performance. To better understand post-exercise autonomic control, we measured heart rate and heart rate variability (HRV) during recovery from exercise in the moderate and heavy domains in ten well-trained endurance athletes. Blood was drawn during recovery for measurement of circulating cortisol. The following day, participants completed three high-intensity intervals before running a 3,000m time trial. Exercise in the heavy domain led to a delay in the recovery of HRV after exercise for the first 20 minutes after exercise with no differences at subsequent timepoints. Exercise in the heavy domain did not increase circulating cortisol or alter whole body metabolism during high intensity exercise the following day; similarly, time trial performance was not impaired following exercise in the heavy domain. These findings suggest that exercise in the heavy domain is well-tolerated by endurance athletes. Further research is needed to better understand these findings in the context of chronic training.