The effect of acute aerobic exercise on stress related blood pressure responses: a systematic review and meta-analysis

The beneficial impact of regular exercise on cardiovascular health is partly mediated by psychobiological mechanisms. However, the effect of acute exercise on psychobiological responses is unclear. Thus, we performed a systematic review of randomised controlled trials (RCTs) that examined the effect of acute aerobic exercise on blood pressure (BP) responses (the change from baseline to stress) to psychosocial laboratory tasks. Fifteen RCTs met inclusion criteria of which ten demonstrated significant reductions in post-exercise stress related BP responses compared with control (mean effect sizes for systolic and diastolic BP, 0.38 and 0.40). Studies involving greater exercise doses tended to show larger effects, with the minimum dose to show a significant effect being 30 min at 50% VO2max. No other moderators emerged from the examination of participant characteristics, research designs and stressor characteristics. In conclusion, an acute bout of aerobic exercise appears to have a significant impact on the BP response to a psychosocial stressor.     

Integrative commentary: Implications of blunted reactivity

The previous issue of the International Journal of Psychophysiology was a special issue that collected some of the latest emerging evidence on blunted reactivity and its relationships with a variety of negative health outcomes. This commentary on the special issue briefly reviews each of the contributions and then provides some thoughts on the general themes that run through these papers. The findings from the special issue suggest that both lower and higher than expected cardiovascular and neuroendocrine responses to active psychological challenges may be maladaptive and differentially associated with adverse health sequelae.     

Haemodynamic reactions to acute psychological stress and smoking status in a large community sample

Exaggerated haemodynamic reactions to acute psychological stress have been implicated in a number of adverse health outcomes. This study examined, in a large community sample, the cross-sectional associations between haemodynamic reactivity and self-reported smoking status. Blood pressure and heart rate were measured at rest and in response to a 3-minute arithmetic stress task. Participants were classified as current, ex-, or non-smokers by their response to a simple prompt. Smokers had significantly smaller SBP and DBP reactions to acute stress than ex- and non-smokers; current and ex-smokers had lower HR reactivity. These effects remained significant following adjustment for a host of variables likely to be associated with reactivity and/or smoking. Although the act of smoking acutely increases haemodynamic activity, the present findings contribute to a growing body of literature showing that smokers have blunted reactivity to mental stress. They also support the hypothesis that blunted reactivity may be characteristic of a range of dependencies. The present results also suggest that smoking status needs to be considered in the design and analysis of stress reactivity studies.     

Aerobic exercise intensity and time of stressor administration influence cardiovascular responses to psychological stress

This study examined cardiovascular responses as a function of time following exercise in which participants were exposed to a laboratory stressor. Ninety (42 women) young (18-35 years old) nonsmoking normotensive participants engaged in 30 min of high and low intensity (75-80% and 50-55% VO(2) max) aerobic exercise and a sedentary control condition. Participants were randomly assigned to a laboratory stressor 5, 30, or 60 min following the exercise bout. Results indicate that low and high intensity exercise significantly reduce heart rate (HR) and systolic and diastolic blood pressure reactivity and HR recovery values. An inverse relationship between intensity of exercise and subsequent cardiovascular reactivity was found. These findings suggest attenuated stress responses following acute exercise depend both on exercise intensity and the time of exposure to psychological stress following exercise.     

Aerobic exercise training and cardiovascular reactivity to psychological stress in sedentary young normotensive men and women

Forty-five (22 women) sedentary young (18-30 years old) nonsmoking normotensive volunteers engaged in either 6 weeks of aerobic training (AT), weight training (WT), or a no-treatment (NT) condition to determine whether AT lowers systolic (SBP) and diastolic (DBP) blood pressure, heart rate (HR), and rate-pressure product (RPP) during rest, psychological stress, and recovery periods. Estimated VO(2)max increased for the AT (32.1+/-1.1 to 38.4+/-1.0 ml.kg(-1).min(-1)). A smaller increase for the WT (30.5+/-1.1 to 33.8+/-1.0) was likely due to increased leg strength, and VO(2)max did not change for the NT (32.5+/-1.1 to 32.9+/-1.0). Heart rate and RPP levels were lower during psychological stress and recovery after training for AT relative to the WT and NT. Overall SBP was also lower in the AT relative to the NT but not the WT. In conclusion, aerobic training lowered cardiovascular activity levels during psychological stress and recovery in healthy young adults, implying a protective role against age-related increases in coronary heart disease for individuals who adopt aerobic exercise early in life and maintain the behavior across the life span.     

Reproducibility of blood pressure and heart rate reactivity: A meta-analysis

Reproducibilities of blood pressure and heart rule (HR) reactivity reported in studies assessing responses to the same laboratory stressors across occasions were reviewed with meta-analytic techniques. Changes in HR had the greatest reproducibility (r =.555), followed by systolic blood pressure (SBP) (.407) and diastolic blood pressure (DBF) (.348), Both SBP and HR response reproducibility was higher at shorter lest-retest intervals, whereas DBP values varied unsystematically with length of test-retest interval Older samples exhibited higher SBP and DBP reproducibility to stressors. SBP and DBP reproducibilities were better for tasks that did not make speech demands. The reliability of reactivity assessment was higher when based on three or more measurements, On the basis of able evidence, the drop in stress reproducibility, as test-retest interval increases, places limits on the viability of BP reactivity as a strong marker or risk factor for coronary heart disease.     

Blunted cardiovascular and cortisol reactivity to acute psychological stress: A summary of results from the Dutch Famine Birth Cohort Study

The Dutch Famine Birth Cohort Study is a large population based study of late middle aged, overall healthy men and women whose health has been followed from 50 to 65 years of age. In a sample of 725 cohort members, an extensive psychological stress protocol was performed during which cardiovascular and cortisol responses were measured. In line with many previous studies, results showed that increased blood pressure responsiveness to the stress protocol was associated with an increased risk for hypertension 5 years later. However, decreased cardiovascular and/or cortisol stress reactivity were associated with obesity and the risk of becoming obese, symptoms of depression and anxiety, a poor self-reported health, poor lung function, and poor cognitive function (all p for statistical tests < 0.05). These associations generally survived adjustment for a range of potential confounders, including resting cardiovascular and cortisol activity, commitment to the stress tasks, sex, age, smoking and use of medication. Results from these studies agree with recent evidence that low biological reactivity to acute psychological stress may not always be beneficial for health but instead seems to be a marker for a range of negative health outcomes. Future studies have to point out whether low stress reactivity precedes or follows these negative health outcomes.     

Cardiovascular reactivity in real life settings: Measurement, mechanisms and meaning

Cardiovascular reactivity to stress is most commonly studied in the laboratory. Laboratory stressors may have limited ecological validity due to the many constraints, operating in controlled environments. This paper will focus on paradigms that involve the measurement of cardiovascular reactions to stress in real life using ambulatory monitors. Probably the most commonly used paradigm in this field is to measure the response to a specific real life stressor, such as sitting an exam or public speaking. A more general approach has been to derive a measure of CV variability testing the hypothesis that more reactive participants will have more variable heart rate or blood pressure. Alternatively, self-reports of the participants’ perceived stress, emotion or demands may be linked to simultaneously collected ambulatory measures of cardiovascular parameters.This paper examines the following four questions: (1) What is the form and what are the determinants of stress-induced CV reactivity in real life? (2) What are the psychophysiological processes underlying heart rate and blood pressure reactivity in real life? (3) Does CV reactivity determined in the laboratory predict CV reactivity in real life? (4) Are ambulatory cardiovascular measures predictive of cardiovascular disease?It is concluded that the hemodynamic processes that underlie the blood pressure response can reliably be measured in real life and the psychophysiological relationships seen in the laboratory have been obtained in real life as well. Studies examining the effects of specific real life stressors show that responses obtained in real life are often larger than those obtained in the laboratory. Subjective ratings of stress, emotion and cognitive determinants of real life stress (e.g. demand, reward and control) also relate to real life CV responses. Surprisingly, ambulatory studies on real life cardiovascular reactivity to stress as a predictor of cardiovascular disease are rare. Measuring the CV response to stress in real life may provide a better measure of the stress-related process that are hypothesized to cause disease than is possible in the laboratory. In addressing these questions, below we review the studies that we believe are representative of the field. Therefore, this review is not comprehensive.     

The effect of mental stress on heart rate variability and blood pressure during computer work

The aim was to evaluate the cardiovascular and subjective stress response to a combined physical and mental workload, and the effect of rest. Twelve females who had no prior experience of laboratory experiments participated in the study. Computer-work-related mental stressors were either added to or removed from a standardized computer work session in the laboratory. Beat-to-beat blood pressure and electrocardiogram (ECG) were recorded continuously during the experiment. The participants reported subjective experiences of stress in six categories using an 11-point scale before and at the end of the work. Heart rate variability (HRV) variables were calculated from the ECG recordings, and a reduction in the high-frequency component of HRV and an increase in the low- to high-frequency ratio were observed in the stress situation compared to the control session. No changes were seen in the low-frequency component of HRV. The stressors induced an increase in blood pressure compared to baseline that persisted, and for the diastolic pressure it even increased in the subsequent control session. No differences were observed for subjective experience of stress with the exception of a time trend in the exhaustion scale, i.e. a progression in reported exhaustion with time. The results—and the dissociation between HRV and blood pressure variables—indicate that HRV is a more sensitive and selective measure of mental stress. It could be speculated that heart rate-derived variables reflect a central pathway in cardiovascular control mechanisms (central command), while the blood pressure response is more influenced by local conditions in the working muscles that partly mask the effect of changes in mental workloads. In the rest period after each work session, HRV and blood pressure variables were partly normalized as expected. However, an 8-min period of rest was insufficient to restore blood pressure to resting values.     

Prospective associations between cardiovascular reactions to acute psychological stress and change in physical disability in a large community sample

Exaggerated haemodynamic reactions to acute psychological stress have been implicated in cardiovascular disease outcomes, while lower reactions have been considered benign. This study examined, in a large cohort, the prospective associations between stress reactivity and physical disability. Blood pressure and pulse rate were measured at rest and in response to a stress task. Physical disability was assessed using the OPCS survey of disability at baseline and five years later. Heart rate reactivity was negatively associated with change in physical disability over time, such that those with lower heart rate reactivity were more likely to deteriorate over the following five years. These effects remained significant following adjustment for a number of confounding variables. These data give further support to the recent argument that for some health outcomes, lower or blunted cardiovascular stress reactivity is not necessarily protective.     

Gender and stress: Differential psychophysiological reactivity to stress reexposure in the laboratory

Research has shown that women are more prone to the development of depression and anxiety disorders throughout their lifetimes. Stress reactivity and adaptation to repeated stressors have been linked to depression and anxiety, but studies examining gender differences in psychophysiological responses to repeated stressors are very limited. This study examined gender differences in response to initial and repeated exposure to a laboratory stressor as well as potential mechanisms for these differences. Participants viewed a Holocaust video on two occasions with a 2-day interval between sessions. Self reported negative affect and cardiovascular reactivity were recorded at both sessions. Although gender differences were not found following initial exposure, women exhibited significantly greater heart rate (HR) and negative affect (NA) reactivity to the second exposure as compared to men. Women also reported significantly greater intrusive thoughts and avoidance after the first exposure than men, but these were not found to be significant mediators. The findings indicate that women may be more vulnerable to repeated stress exposures compared to men suggesting sensitization. The implications of our findings and suggestions for future research are discussed.     

Type D personality is associated with low cardiovascular reactivity to acute mental stress in heart failure patients

Background

The distressed (Type D) personality is associated with adverse coronary heart disease outcomes, but the mechanisms accounting for this association remain to be elucidated. We examined whether myocardial and hemodynamic responses to mental stress are disrupted in Type D patients with chronic heart failure (HF).

Methods

Ninety-nine HF patients (mean age 65 ± 12 years; 75% men) underwent a public speech task, during which heart rate (HR) and blood pressure (BP) were recorded. Type D personality and its components negative affectivity (NA) and social inhibition (SI) were assessed with the DS14. General linear models with repeated measures and logistic regression were used to assess differences in stress response and recovery.

Results

Type D personality was associated with a reduced HR response (F_1,93 = 4.31, p < .05) independent of the use of beta adrenergic blocking agents and the presence of atrial fibrillation. There were no differences between HF patients with and without a Type D personality with respect to the BP response. Examining continuous NA and SI scores and their interaction (NA ∗ SI), revealed a significant association of NA ∗ SI with the SBP response (F_1,93 = 4.11, p < .05), independent of BP covariates. Results with respect to HR and DBP responses were comparable to the findings using the dichotomous Type D measure. No significant associations between Type D and recovery patterns were found.

Conclusion

HF patients with Type D personality may show an inadequate response to acute social stress, characterized by a blunted HR response.     

Enhancing the laboratory-to-life generalizability of cardiovascular reactivity using multiple occasions of measurement

Studies examining the association between laboratory measures of stress-related cardiovascular (CV) reactivity and responses to psychological challenges in the natural environment have yielded mixed results. Frequently, single laboratory tasks have been used to predict responses to natural stressors on a single occasion of measurement. Because aggregation broadens the range of stimuli sampled and reduces measurement error, laboratory-to-life generalizability should be more easily detected when multiple predictor and criterion observations are used. Sixty students in a public speaking course were administered multitask assessments of CV reactivity during two laboratory sessions and during two in-class public speech assignments. CV responses to the classroom speeches were greater among those who showed larger responses in the laboratory, and these associations became stronger as measures were aggregated across multiple samples of behavior. These results support the generalizability of CV reactivity as a measure of individual difference, and they help to shed light on previous inconsistent findings in this area.     

Gender differences and the relationships of perceived background stress and psychological distress with cardiovascular responses to laboratory stressors

The primary aim of this study was to evaluate the relationships of perceived background stress and self-reported psychological distress on cardiovascular reactivity during acute laboratory stressors. The Perceived Stress Scale (PSS) was used as the measure of perceived background stress, and the General Health Questionnaire (GHQ) was used as the measure of psychological distress. A secondary aim was to examine whether background stress and psychological distress affected the susceptibility to induction of a negative mood using music. Heart rate (HR) and blood pressure (BP) were measured in 149 female and male college students at rest and during a stressful mental arithmetic (MA) task and a mood induction procedure. Higher scores on the GHQ were associated with lower systolic BP reactivity during the MA task by all participants. Higher scores on the PSS and GHQ were also associated with lower diastolic BP and HR reactivity, but only in females. Thus, higher self-reports of background stress and psychological distress tended to result in blunted reactivity to an acute laboratory challenge. Higher levels of background stress and psychological distress were not associated with greater susceptibility to a negative mood induction. This study adds to the growing literature indicating that potentially negative health outcomes may be associated with diminished cardiovascular reactivity under certain conditions.     

Hemoconcentration during a prolonged stress task: Associations with hemodynamic reactivity and microvascular permeability

This study explored the association between stress-induced hemoconcentration and plasma colloid osmotic pressure, hemodynamic reactivity, and microvascular permeability during a protracted stress task in 26 healthy, young participants. Microvascular permeability was measured during rest using venous congestion plethysmography in a subsample of 13 participants. The task increased hematocrit, colloid osmotic pressure, blood pressure, and heart rate and decreased R-wave to pulse interval. Resting microvascular permeability was not correlated with hemoconcentration. Colloid osmotic pressure and diastolic blood pressure were associated with stress-induced hemoconcentration throughout the task. The association with systolic blood pressure as well as heart rate, however, was more evident during the initial 8 min of the task than throughout the total task duration. These findings suggest that factors associated with hemoconcentration vary with task duration.     

Stability of individual differences in cardiovascular reactivity

Examining the stability of individual differences in cardiovascular reactivity, 42 male subjects were presented a difficult cognitive task to perform at each of two experimental sessions, scheduled 1 week apart, and recordings of hear rate and systolic and diastolic blood pressure obtained during periods of rest and task performance on each occasion of testing. Measures of task-related arousal (reactivity) across the two experimental sessions revealed substantial and reliable individual differences on all three response variables, as evidenced by (1) subsets of subjects representing clearly differentiated groups of Reactors and NonReactors on each measure and (2) correlation of reactivity scores of all subjects between the first and second sessions. While individual differences in systolic blood pressure and heart rate reactivity correlated positively, magnitude of systolic and diastolic blood pressure responses did not covary reliably among subjects. It was concluded that the present data demonstrate consistency, or reproducibility, of idiosyncratic cardiovascular reactivity and suggested that the variability of relationships among response measures may reflect more basic dimensions of individual differences involving neuroregulatory mechanisms underlying cardiovascular adjustments.     

The influence of social stress on time perception and psychophysiological reactivity

Time perception is a fundamental component of everyday life. Although time can be measured using standard units, the relationship between an individual's experience of perceived time and a standard unit is highly sensitive to context. Stressful and threatening stimuli have been previously shown to produce time distortion effects, such that individuals perceive the stimuli as lasting for different amounts of time as compared to a standard unit. As a highly social species, humans are acutely sensitive to social stressors; however, time distortion effects have not been studied in the context of social stress. We collected psychophysiological (electrocardiogram and impedance cardiography) and time perception data before, during, and after a modified version of the Trier Social Stress Test for 42 participants. Based on prior theories and evidence from the time perception literature, we hypothesized that experiencing a stressful event would result in time distortion. This hypothesis was supported by the data, with individuals on average reproducing short and long duration negative and positive stimuli as lasting longer after experiencing social stress, t(41) = −3.55, p = .001, and t(41) = −4.12, p < .001 for negative stimuli, and t(41) = −2.43, p = .02, and t(41) = −3.07, p = .004 for positive stimuli. However, changes in time perception were largely unrelated to psychophysiological reactivity to social stress. These findings are in line with some other studies of time distortion, and provide evidence for the interoceptive salience model of time perception. Implications for mechanisms of time distortion are discussed.     

Effect of meal content on heart rate variability and cardiovascular reactivity to mental stress

Little is known about transient effects of foods and nutrients on reactivity to mental stress. In a randomized crossover study of healthy adults (n=20), we measured heart rate variability (respiratory sinus arrhythmia), blood pressure, and other hemodynamic variables after three test meals varying in type and amount of fat. Measurements were collected at rest and during speech and cold pressor tasks. There were significant postmeal changes in resting diastolic blood pressure (-4%), cardiac output (+18%), total peripheral resistance (-17%), and interleukin-6 (-27%). Heart rate variability and hemodynamic reactivity to stress was not affected by meal content. We recommend that future studies control for time since last meal and continue to examine effects of meal content on heart rate variability.     

Cardiovascular stress reactivity tasks successfully predict the hypotensive response of isometric handgrip training in hypertensives

This study aimed to determine whether: (a) isometric handgrip (IHG) training lowers resting blood pressure (BP), (b) cardiovascular reactivity to a serial subtraction (SST), IHG (IHGT), and cold pressor (CPT) task predicts this hypotensive response, and (c) cardiovascular reactivity is attenuated posttraining. Resting BP and cardiovascular reactivity to a SST, IHGT, and CPT were measured in 24 hypertensives (51–74 years) before and after 10 weeks of IHG training (n = 12) or control (n = 12). IHG training lowered resting BP (Δ8/5 mmHg), whereby the decrease in systolic BP was correlated to pretraining systolic BP reactivity to the SST (r = ?.85) and IHGT (r = ?.79; all ps < .01), but not the CPT (r = .34; p > .01). Furthermore, following IHG training, systolic BP reactivity to the SST (Δ7 mmHg) and IHGT (Δ8 mmHg) was reduced (all ps < .01). The results offer promising implications for hypertensives and may provide a tool to identify IHG training responders.     

Aerobic Fitness and Opioidergic Inhibition of Cardiovascular Stress Reactivity

The role of endogenous opioids in aerobic fitness-induced decrements in cardiovascular stress reactivity was examined by comparing the effects of opioid antagonism with naltrexone on responses to stress in young adults with high versus low levels of aerobic fitness. Two hundred forty subjects were given an activity questionnaire and males with the highest (Fit) and lowest (Nonfit) aerobic activity profiles were recruited for maximal oxygen consumption (VO2max) treadmill testing and psychological stress testing (final sample N = 28). Heart rate and blood pressures were measured during performance on a computer-controlled arithmetic task after pretreatment with either naltrexone (Trexan, DuPont) or a placebo. During placebo challenges, Fit subjects, compared with Nonfit, showed lower heart rate reactivity during stress and lower mean arterial blood pressures immediately before and during recovery from stress. Naltrexone eliminated these reactivity differences by increasing heart rate reactivity and raising mean arterial blood pressure in Fit subjects. These data suggest that aerobic fitness is associated with enhanced opioidergic inhibition of circulatory stress reactivity. Opioidergic modulatory effects on stress reactivity may comprise an important mechanism in fitness-associated risk reduction for cardiovascular disease.