Hemodynamic responses during and after multiple sets of stretching exercises performed with and without the Valsalva maneuver

OBJECTIVE:

This study investigated the acute hemodynamic responses to multiple sets of passive stretching exercises performed with and without the Valsalva maneuver.

METHODS:

Fifteen healthy men aged 21 to 29 years with poor flexibility performed stretching protocols comprising 10 sets of maximal passive unilateral hip flexion, sustained for 30 seconds with equal intervals between sets. Protocols without and with the Valsalva maneuver were applied in a random counterbalanced order, separated by 48-hour intervals. Hemodynamic responses were measured by photoplethysmography pre-exercise, during the stretching sets, and post-exercise.

RESULTS:

The effects of stretching sets on systolic and diastolic blood pressure were cumulative until the fourth set in protocols performed with and without the Valsalva maneuver. The heart rate and rate pressure product increased in both protocols, but no additive effect was observed due to the number of sets. Hemodynamic responses were always higher when stretching was performed with the Valsalva maneuver, causing an additional elevation in the rate pressure product.

CONCLUSIONS:

Multiple sets of unilateral hip flexion stretching significantly increased blood pressure, heart rate, and rate pressure product values. A cumulative effect of the number of sets occurred only for systolic and diastolic blood pressure, at least in the initial sets of the stretching protocols. The performance of the Valsalva maneuver intensified all hemodynamic responses, which resulted in significant increases in cardiac work during stretching exercises.     

A pilot study of some associations between behavioural stressors and physiological processes in healthy men

Summary A study was made of the physiological effects of smoking, psychological stressors, heat, exercise, and fat ingestion on 12 healthy men. Repeated measurements were made of cardiovascular, neuroendocrine, enzyme, lipid, and other variables in all stressor situations. The main findings were that psychological stressors and exercise were associated with more and larger physiological changes than the other stressors, and widespread response differences in addition to those in lipids were identified between subgroups of seven normolipidaemic men and five hypertriglyceridaemic men.     

Stress reactivity of intraocular pressure after relaxation training in open-angle glaucoma patients

The present study was based on the hypothesis that stress may contribute to increased intraocular pressure (IOP) in open-angle glaucoma patients. It is investigated whether IOP reactivity to a mental stressor test (MST) can be influenced by relaxation training. Twenty three patients with open-angle glaucoma were randomly assigned either to a training group (TG) or to a waiting-list control group (CG). Prior to as well as after the completion of the training all patients were exposed to the MST. IOP and heart rate as well as self-ratings of psychological strain were assessed three times: (1) at baseline, (2) after exposition to the stressor, and (3) after a 10-min relaxation phase. Results provide evidence that the MST is a valid procedure to induce psychophysiological activation and that elevated IOP levels in open-angle glaucoma patients might be provoked by stressing situations. However, participation in the relaxation training did not influence IOP stress reactivity.     

The impact of deployment length and experience on the well-being of male and female soldiers

This study examined the effects of stressor duration (deployment length) and stressor novelty (no prior deployment experience) on the psychological health of male and female military personnel returning from a peacekeeping deployment. The sample consisted of men (n = 2,114) and women (n = 1,225) surveyed for symptoms of depression and posttraumatic stress. The results confirmed the hypotheses. Longer deployments and 1st-time deployments were associated with an increase in distress scores. However, the relationship between deployment length and increased distress was found only for male soldiers. The findings demonstrate the importance of considering the impact of exposure to long-term occupational stressors and confirm, in part, previous research that has demonstrated a different stress response pattern for men and women.     

Interactive effects of type A personality and psychological and physical stressors on human cardiovascular functions

The first part of this study examined the relationship(s) between Type A behavior scores and heart rate, blood pressure and impedance derived cardiovascular measures in response to discrete stressors during a standardized psychophysiological assessment. Expts. 2A and 2B considered cardiovascular responses to dynamic exercise stress alone and in combination with psychological and cold pressor tests. Gender and stroke volume changes during the psychological stress correlated 0.45 (P less than 0.02) with Type A score. Subscale scores of Job Involvement correlated 0.78 (P less than 0.02) with stroke volume, total systemic resistance and heart rate during the psychological stressor, and systolic blood pressure during the cold pressor task. The combined effects of psychological stress and dynamic exercise on systolic and diastolic blood pressure were significantly greater than the individual effects of these stressors. The use of impedance cardiography in measuring cardiovascular variables that correlate with Type A behavior, during psychophysiological assessments, may further elucidate our understanding of Type A behavior in addition to providing information about how stress interacts with aerobic exercise.     

The effect of laboratory stressors on glycemic control and gastrointestinal transit time

This study compared effects of an active coping task (computerized stressors involving arithmetic, anagrams, and Atari games) and a passive coping task (cold pressor) on gastrointestinal transit time and glycemic response to an oral glucose load. Eleven normal weight males were studied; subjects participated in three counterbalanced sessions, each including a 45-minute baseline, 20-minute experimental period (active coping, passive coping, or nonstress control) and 2.5-hour recovery period. The stressors produced different cardiovascular and catecholamine responses; systolic and diastolic blood pressure were highest during cold pressor (p less than 0.001), heart rate was highest during computer stressor (p less than 0.001), and norepinephrine excretion was greatest during cold pressor (p less than 0.002). However, both stressors delayed gastrointestinal transit time compared with the control condition (p less than 0.009 and p less than 0.026 for cold pressor and computerized stressor, respectively) and both delayed the time of peak glucose response (p less than 0.002 and p less than 0.05, respectively). Implications of these findings for patients with diabetes and for effects of stress on eating behavior are discussed.     

The Effects of Stress on Natural Killer Cell Activity in Healthy Men1

Several studies have shown that exposure to acute laboratory stressors produces an immediate change in immune function. We examined the effects of a mild laboratory stressor on natural killer (NK) cell cytotoxicity and on psychological and cardiovascular measures in 24 adult males. Subjects in the experimental condition worked on the Stroop task without interference for 30 min with blood samples drawn at baseline, 10, 20, and 30 min into the task, and 40 min after completing the task. The 30-min stressor produced increases in self-reported stress and tension, and in SBP, DBP, and HR. It was also associated with a decrease in NK cell cytotoxicity 40 min after the stressor. Results are discussed in relation to the effects of mild and intense stressors and future research implications.     

Physical fitness and the stress process

In the current paper we focus on the role of physical fitness in the life stress process for both psychological and physical well‐being. The major research question posed in the current study is: Does physical fitness deter distress in a model containing the major components of the life stress process? That is, do individuals who exercise show higher levels of well‐being than those that do not exercise? Is this relationship independent of the stress they experience and the resources they possess? Using data from a representative community sample, the current study finds that physical fitness is directly related to both psychological and physical distress. The more a person exercises, the less psychological and physical symptoms he or she manifests. Physical fitness is associated with decreased distress. This finding holds up, even when stressors and psychosocial resources are included in the model. While physical fitness was not found to mediate the effects of stressors on distress, there was some evidence of a moderating effect of fitness in the stressor–distress relationship, both for psychological and for physical distress. That is, fitness served to buffer the effects of stressors on both psychological and physical distress. In addition, physical fitness is associated with psychological resources that, in turn, are associated with lower levels of distress. The more a person exercises, the greater the self‐esteem. Thus, in addition to directly deterring distress, physical fitness was found to have the potential to indirectly deter distress through its positive association with the level of psychological resources (i.e., self‐esteem) that individuals possess. These and other findings are discussed in the context of the life stress paradigm. Implications for future stress research are presented. © 2004 Wiley Periodicals, Inc. J Comm Psychol 32: 81–101, 2004.     

Cardiovascular response to stress

The behavioral characteristics of psychological stressors have been operationally defined. A psychological stressor is one that causes a stress response in a predictable percentage of index subjects. However, it may not always produce a stress response, and the probability of producing such a response depends on interactions between the behavioral situation and the individual involved. Thus there is a danger that a psychological stressor will be defined according to the stress response it causes rather than its structural characteristics. The characteristics that enhance the likelihood that a psychological stressor will cause a stress response are its novel, challenging, or threatening aspects that engage a subject in continuous active mental effort. The intensity of the stress response depends on the intensity of mental effort exerted to meet a challenging situation, whether or not that situation is perceived as threatening. The behavioral response to a psychological stressor also has been defined. It includes somatomotor, neuroendocrine, and cardiovascular components. The somatomotor response to stressful psychological events includes purposeful active coping to counter the challenge or threat posed by the stressor. The neuroendocrine response includes a combination of pituitary-adrenal cortical and hypothalamic-sympathetic-adrenal medullary secretions. The cardiovascular response includes a combination of increased rate and force of cardiac contraction, skeletal muscle vasodilation, venoconstriction, splanchnic vasoconstriction, renal vasoconstriction, and decreased renal excretion of sodium. Of all the modifiers that influence the stress response to a psychological stressor, family history is the one most likely to have an effect. A family history of essential hypertension increases the likelihood that a subject will respond to a psychological stressor with a cardiovascular stress response pattern. Other predisposing characteristics that increase the likelihood of a stress response include behavioral patterns of response to challenge or threat but may also include anatomic or biochemical characteristics that increase susceptibility to neurogenic activation of central aminergic mechanisms.     

The effects of nonconcurrent and concurrent relaxation training on cardiovascular reactivity to a psychological stressor

Eight patients in a cardiac rehabilitation program, after exposure to two psychological stressors approximately equivalent with respect to cardiovascular reactivity, were given nonconcurrent progressive muscle relaxation training and retested for reactivity. They were then provided with relaxation training concurrently with one of the stressors and exposed again to the two stressors. No significant effects for nonconcurrent progressive muscle relaxation training were detected. Concurrent training, in contrast, produced reductions in both systolic and diastolic blood pressure. Reductions resulting from training on the target stressor showed little tendency to generalize to the nontarget stressor; the discrimination was particularly well defined for systolic blood pressure. We conclude that muscle relaxation techniques are maximally effective in reducing reactivity to psychological stressors when relaxation training is provided concurrently with the stressor. Our findings further suggest that to inculcate the relaxation response reliably across different situations, specific training to enhance generalization may be needed.     

Evidence for a lack of phasic inhibitory properties of habituated stressors on HPA axis responses in rats

This experiment tested the hypothesis that habituation to repeated stressor exposures is produced by phasic inhibitory influence on the neural circuitry that normally drives the paraventricular nucleus of the hypothalamus and subsequently the adrenocortical hormone response to psychological stress. Such a process would be expected to lower the acute response to a novel stressor when experienced concurrently with a habituated stressor. Rats were exposed to restraint or no stress conditions for 14 consecutive days. On the 15th day, the rats were exposed to the control condition (no stress), acute restraint, loud noise, or restraint and loud noise concurrently. Blood was taken and assayed for ACTH and corticosterone and brains were collected to examine c-fos messenger RNA expression in several brain areas. As predicted, the rats that received the same (homotypic) stressor repeatedly and again on the test day displayed low levels of ACTH and corticosterone, similar to the control conditions (i.e., showed habituation). All rats that received a single novel stressor on the test day, regardless of prior stress history, exhibited high levels of ACTH and corticosterone. The rats that received two novel stressors also displayed high levels of ACTH and corticosterone, but little evidence of additivity was observed. Importantly, when a novel stressor was concurrently given with a habituated stressor on the test day, no reduction of HPA axis response was observed when compared to previously habituated rats given only the novel stressor on the test day. In general, c-fos mRNA induction in several stress responsive brain areas followed the same patterns as the ACTH and corticosterone data. These data suggest that habituation of the adrenocortical hormone response to psychological stressors is not mediated by phasic inhibition of the effector system.     

Association between smoking status and cardiovascular and cortisol stress responsivity in healthy young men

Acutely, cigarette smoking stimulates increases in blood pressure (BP). heart rate (HR), and cortisol, but little evidence is available concerning the impact of habitual smoking status on cardiovascular stress responsivity. This relation was assessed in 86 healthy male firefighters, age 19 to 31, comprising 52 nonsmokers and 34 smokers. Measures of BP, HR, salivary free cortisol, breathing pattern, and self-reported stress and alertness were obtained while subjects performed nonverbal mental arithmetic and a socially evaluative speech task. Systolic and diastolic BP were higher at rest in nonsmokers than smokers, and a consistent difference in stress responsivity was also found. BP, HR, and cortisol responses to mental arithmetic were significantly smaller in smokers than nonsmokers, with mean changes in BP (adjusted for body weight) averaging 19.3/1 l.0 mmHg and 28.5/15.4 mmHg in smokers and nonsmokers, respectively. There were no effects of smoking status on task performance or subjective stress responses and no differences between groups in family health history, health-related behaviors, or psychological characteristics that might account for the reactivity difference. Possible explanations of the results are discussed, and methodological implications for cardiovascular stress reactivity studies are outlined. This study was supported by the Medical Research Council, UK     

The role of stressors and psychosocial variables in the stress process: a study of chronic caregiver stress

OBJECTIVE: An investigation was conducted 1) to examine the relative importance of stressor types (ie, daily hassles, caregiving-specific stressors, and life events) on the stress response, 2) to assess the stability of relationships between psychosocial variables and stress over a 6-month period, and 3) to explore how the nature and magnitude of the contributions made by stressors and psychosocial factors to the stress process varied according to the qualitative characteristics of the stress response (ie, anxiety, depression, and stress). METHODS: Fifty spousal caregivers of patients with dementia were recruited and asked to participate in a detailed psychosocial evaluation at 3-month intervals; the evaluation involved measurement of stressor frequency, psychosocial variables, and indices of the stress response (ie, anxiety, depression, and stress). RESULTS: The data revealed that the effects of stressors and psychosocial factors on the stress response were considerable (accounting for 49-63% of the variance in stress response measures). Furthermore, there was some evidence of stability in the effects of the stressor and mediator variables on the stress response. Specifically, the contributions of life events and caregiver difficulties were largely consistent at both 3 and 6 months, and the psychosocial factor of "reactive coping and self-appraisal" influenced all three stress response indices at both 3 and 6 months. CONCLUSIONS: There is some evidence of stability in the effects of stressors and psychosocial variables on the stress process over a 6-month period. However, it would also seem that the nature of the stress process differs according to the qualitative characteristics of the stress response.     

Acute Emotional and Cardiovascular Effects of Stressful Mental Work During Aerobic Exercise

The acute effects of engaging in challenging mental work during a single session of aerobic exercise were examined on measures of subjective mood and cardiovascular function. Fifty-seven female subjects were randomly assigned to participate in either a 10-min aerobic exercise condition or a no-exercise control condition. Half of the subjects in each group performed digits backward problems during this time period, and no mental stressors were presented to the other subjects. The results indicated that the exercise and mental stress conditions had additive effects on subjective anxiety levels and on cardiovascular responses during exercise. Both exercise and mental stress increased heart rate. In addition, exercise had anti-anxiety and vasodilative effects, but both of these influences were attenuated by opposing main effects for mental stress exposure. No effects were found for exercise on measures of cardiovascular reactivity to a later digits backward stressor. The results are consistent with previous research in suggesting that exposure to mental stressors during aerobic exercise provides no acute psychological benefits but attenuates some of the mood improvements and vasodilative effects of the exercise activity.     

Psychophysiological and neuroendocrine responses to laboratory stressors in women: Implications of menstrual cycle phase and stressor type

This study assessed stressor and menstrual phase effects on psychophysiological and neuroendocrine responses to laboratory stressors in freely cycling women (N = 78, ages 18-45). Participants performed counterbalanced stressors [Paced Auditory Serial Addition Test (PASAT) or cold pressor test (CP)] during their follicular and luteal menstrual cycle phases between 1:00 and 3:00 p.m. to control for cortisol rhythm. Participants rested 30-min, performed the stressor, and then recovered 30-min while electrocardiography continuously monitored heart rate (HR). Systolic (SBP) and diastolic blood pressure (DBP), salivary cortisol, and state anxiety were assessed at timed intervals. HR, SBP, and cortisol varied more over the course of luteal than follicular phase testing. A three-way interaction revealed state anxiety reactivity was greater with the PASAT during the follicular phase. DBP showed equal and persistent reactivity with both stressors during both cycle phases. Results extend the stressor-specific HPAA hypothesis and have important methodological implications for women's biopsychology research.     

Psychological stress and neuroendocrine function in humans: the last two decades of research

This paper reviews experimental contributions published in the last two decades and exploring the effect of emotional stress on neuroendocrine function in healthy humans. Laboratory studies allow standardization of the stressor and better control for known confounding factors. Commonly used stressors are mental arithmetics, speech tasks, the Stroop test, videogame playing, films or videotapes and interviews. Little is known about the generalizability of laboratory results, with some studies suggesting great caution in extrapolating data to real-life stress conditions. Another strategy is studying the psychoendocrine reaction to real-life stressors, such as bereavement or anticipated loss, academic examinations, everyday work and parachute jumping. The effects of different stressors on neuroendocrine axes are reviewed, as well as the influence of gender, age, personality, coping style, social support, biological and nonbiological interventions. The subjective perception of the situation is probably a main determinant of the psychoendocrine response pattern. In fact, marked variability in individual responses to a variety of stressors has frequently been observed. Evidently, the 'objective' characteristics of a given event are not the only determinants of reaction to the event itself. According to a constructivistic perspective, every given stressor has a strictly personal and idiosyncratic meaning and loses its 'objective' characteristics. Of course, biological factors may also play a part. In any case, it is mandatory to overcome a rigid dichotomy between psychological and biological processes. Dualistic conceptions which imply a determination of the physical by the psychological or vice versa should give place to a systemic conception, which implies mutual, circular interactions.     

Electrodermal Reactivity: An Analysis by Age and Sex

Abstract

Resting electrodermal levels and electrodermal response to Valsalva maneuver were measured in males and females of three age groups (young, middle-aged, old). Significant sex and age effects were observed. Young and middle-aged females had lower electrodermal resting levels than males. These differences were reversed for the young age group during a Valsalva maneuver, where the females gave larger specific responses. With old age, sex differences diminished, resting state conductance levels decreased, but the specific conductance responses to Valsalva remained relatively unchanged. Results demonstrate interactive age and sex effects on the electrodermal measure. Possible relevance of the data to sex differences in adaptation and stress response are discussed.     

Meta‐analysis of digital game and study characteristics eliciting physiological stress responses

Digital games have been used as stressors in a range of disciplines for decades. Nonetheless, the underlying characteristics of these stressors and the study in which the stressor was applied are generally not recognized for their moderating effect on the measured physiological stress responses. We have therefore conducted a meta‐analysis that analyzes the effects of characteristics of digital game stressors and study design on heart rate, systolic and diastolic blood pressure, in studies carried out from 1976 to 2012. In order to assess the differing quality between study designs, a new scale is developed and presented, coined reliability of effect size. The results show specific and consistent moderating functions of both game and study characteristics, on average accounting for around 43%, and in certain cases up to 57% of the variance found in physiological stress responses. Possible cognitive and physiological processes underlying these moderating functions are discussed, and a new model integrating these processes with the moderating functions is presented. These findings indicate that a digital game stressor does not act as a stressor by virtue of being a game, but rather derives its stressor function from its characteristics and the methodology in which it is used. This finding, together with the size of the associated moderations, indicates the need for a standardization of digital game stressors.     

The effect of acute stress on subsequent neuropsychological test performance (2003).

Acute mental stressors have been implicated as variables that may deleteriously affect neuropsychological test performance by increasing distractibility and decreasing working memory function. This study examined 25 subjects with no known neurological or psychiatric impairment on a brief battery of neuropsychological measures on alternate days following either rest or induced mental stress in a counterbalanced design. The test battery consisted of the Rey Auditory-Verbal Learning Test, the Rey Complex Figure, and three Wechsler Memory Scale-III subtests (Logical Memory, Digit Span, and Visual Memory Span). The Ss average age was 24.8 years (S.D. = 10.1) and average education was 15.0 years (S.D. = 1.6). The mental stressor employed was a videotaped public-speaking exercise that has been shown in previous work to induce negative mood, cardiovascular reactivity, and perceived mental stress. Ss demonstrated statistically significant (P < .05) increases in negative mood, heart rate, diastolic blood pressure, and systolic blood pressure as well as elevated cortisol concentration following induced stress, suggesting substantially increased adrenocortical reactivity and cardiovascular stress response. There were, however, no statistically significant differences in any of the neuropsychological measures when stress versus rest days were compared. The results suggest that acute mental stressors may have no measurable effect on subsequent performance on selected neuropsychological tests in a normal population. Further work is suggested to determine whether pre-existing anxiety-related psychopathology or pre-existing neurological compromise might interact with induced mental stress to cause decrements in neuropsychological test performance.     

Forced ventilation increases variability of isometric finger forces

The study aimed to assess the effects of forced ventilation on variability of the index finger force at the submaximal levels. Fourteen (6 men, 8 women) healthy subjects were instructed to perform self-initiated forced inspiration and forced expiration, the Valsalva maneuver and normal breathing while sustaining 15%, 30%, and 45% of maximal voluntary contraction (MVC) by the index finger. Standard deviation (S.D.) of finger forces increased significantly with the level of force. At each level of force, the mean force was not significantly changed under different breathing conditions. S.D. and coefficient variation (CV) during forced inspiration and expiration was significantly greater than S.D. and CV during normal breathing and the Valsalva maneuver at each force level. No significant differences in S.D. and CV were found between forced inspiration and expiration or between normal breathing and the Valsalva maneuver. Force variability synchronized with the initiation of forced inspiration and expiration, but not with the ventilation data during the Valsalva maneuver or normal breathing. These findings demonstrate clearly that finger force variability is affected by specific ventilation patterns at submaximal force levels. Therefore, assessment of force variability should consider the influence of ventilation.