The effects of physical exercise on psychophysiological reactions under stress

Abstract

The effects of moderate physical exercise during a 20-minute anticipation period of a public speech were investigated. Mood before the anticipation period was manipulated as an additional stress factor. As a third experimental factor the subjects were given the opportunity for task preparation or not. Besides cardiovascular variables and self-reports of bodily symptoms, mood reports served as dependent variables and as indicators of general well-being. Eighty female students took part in the study. Moderate exercise was associated with strongly increased activation and reports of related bodily symptoms. The reported mood changes as a function of exercise included a decrease in anxiety and an increase in self-reliance. This mood repair effect of exercise was especially apparent when the subjects entered the anticipation period in a negative emotional state. The exercised subjects spoke with greater calmness. The task preparation during anticipation led to slightly increased activation and to reports of bodily symptoms as well as increased anxiety and less self-reliance. The prepared subjects made fewer pauses in their speeches.     

Twisting the night away: the effects of all night disco dancing on reaction time

8 subjects performed an unprepared simple reaction time task for 20 min. every 2 hr. while taking part in an all night disco dancing marathon (continuous exercise) and during a control (no exercise) night. Mean reaction times were significantly faster and less variable during the dance marathon. It was suggested that the effects of continuous exercise in the form of disco dancing may be to reduce drowsiness which in turn assists performance.     

Anxiety and heart rate under psychological stress: The effects of exercise-training

Abstract The effects of a 12-week exercise-training program on cognitive, somatic, and behavioral anxiety and on heart rate responses to evaluative stress were scrutinized in 89 subjects randomly assigned to an experimental (exercise) or a control group. The training program consisted of exercises that were aimed to the improvement of the general physical fitness (i.e., strength, flexibility, and endurance). Following the 12-week training period, exercising subjects showed improved motor skill capacity as well as higher VO(2) max. In an anxiety inciting test situation, that consisted of the video-taped delivery of a 5-min speech, a mental arithmetic and a fine motor task, exercising subjects showed more favourable responses than control subjects in three ways: (a) they exhibited lower behavioral anxiety during the anticipation phase of the three stressors, (b) they reported lower cognitive and somatic anxiety during the anxiety provoking situation, and (c) their heart rate recovered faster, in contrast to both their baseline heart rate and the control subjects' heart rate, from the stress episode. These results demonstrate that a fitness-oriented exercise program has anxiolytic properties. They also provide a primary evidence that overt behavioral anxiety, as opposed to the usually measured self-reported anxiety, may be affected by exercise.     

Alcohol use and stress in women: The role of prior vs. anticipated stressors

The present study investigated stress-related drinking in women. Alcohol consumption in response to stress and in anticipation of a stressor was examined to evaluate women's use of alcohol to cope with stress. Subjects were assigned to one of four conditions in a 2 × 2 factorial design in which order of alcohol consumption and stress task as well as stress level was manipulated. Findings indicate that subjects did not consume alcohol to cope with the effects of either a prior stressor or an upcoming stressor. These results suggest the need for further refinement of notions concerning women's use of alcohol to cope with stress.     

Valence,form, and content of self-talk predict sport type and level of performance

In this paper, we aimed to test whether we could predict sport type (badminton or running) and marathon proficiency from the valence, form, and content of the athletes’ self-reported inner speech. Additionally, we wanted to assess the difference between self-talk during high intensity and low intensity exercise. The present study corroborated existing research – we were able to predict both sport type in Study 1 and intensity level as well as marathon proficiency in Study 2 from questionnaire data using machine learning models. In Study 1, we found that badminton players engage more in worry and anxiety-control while runners are more prone to task disengagement. Interestingly, it seemed in Study 2 that the more participants engaged in condensed, positive, and repetitive self-talk when not pushing themselves, the slower their fastest marathons and half marathons were. We discuss potential explanations for these findings and make suggestions for future research.     

Visual vs. verbal stimulus set in a letter-classification task

In three experiments, subjects classified briefly presented letters as belonging to either the first or the second half of the alphabet. Prior to each target letter, the subjects were given either a verbally named letter (verbal set), a letter presented visually for 3 sec (visual set), or no prior alternative (control). The target was equally likely to be the same as the prior alternative (same trials) or from the opposite half of the alphabet (different trials). Classification accuracy was always greater for visual set than for the control condition. Verbal-set accuracy was no better than control accuracy when the verbal alternative immediately preceded the target but was equal to visual-set accuracy when the alternative preceded the target by 3 sec. In both set conditions, subjects tended to choose the same half of the alphabet as the prior alternative. It was concluded that type and timing of prior alternatives are important variables in accounting for enhanced classification accuracy.     

Mood change and marathon running: A pilot study using a Swedish version of the POMS test

Regular exercise is said to have positive effects on mood, especially if the exercise intensity is low to moderate. However, the acute effects resulting from participation in a strenuous competition, such as a marathon race, have been studied less. The present investigation used the Profile of Mood States (POMS) test to measure mood, before and after the 1989 Stockholm Marathon. A total of 106 male runners (mean age 40.0 years), with finishing times between 3h and 3h 45 min participated as subjects. Results showed great changes between pre- and post-marathon scores, most of them significant at the p less than 0.001 level. Furthermore, differences between a faster and a slower group of runners were demonstrated with regard to mood states, even though plasma glucose levels were comparable. It is concluded that participation in a marathon race greatly effects mood, mainly in a more negative way than low to moderately intense exercise does.     

Moderators of the association between exercise identity and obligatory exercise among participants of an athletic event

Previous research has connected exercise identity with obligatory exercise, yet to date no empirical studies have identified moderator variables of this association. The current study included participants of an athletic event (full marathon, n = 582; half marathon, n = 1,106; shorter distance, n = 733) who completed questionnaires about exercise behaviors, obligatory exercise, and internalization of both the thin-ideal and athletic-ideal body shapes. General linear model analyses were conducted to examine the exercise identity–obligatory exercise relationship; moderator variables included gender, internalization of the thin-ideal body shape, and internalization of the athletic-ideal body shape. After controlling for the effects of body mass index, age, and distance group, the three-way interaction of exercise identity, gender, and internalization of the athletic-ideal body shape predicted obligatory exercise. Findings suggest that women who report high identification with exercise and high value on having an athletic physique may be vulnerable to obligatory exercise.     

The generality of learned helplessness in the rat

Two experiments were simultaneously conducted in which two different groups of 40 rats each were exposed to one of two different stressors. In both experiments half the subjects were pretreated with shock, half with underwater exposure. For each pretreatment stressor, half the subjects were allowed to escape, the other half were not. The experiments differed in the test task used. Approximately 24 hr after pretreatment, one-half the subjects from each pretreatment group received 20 water-escape trials in an underwater maze, the other half received 20 shock-escape trials in a two-way shuttle box. The subjects in each of the inescapable pretreatment conditions were slower to escape in the subsequent shock-escape and water-escape tasks when compared with subjects in the corresponding escapable pretreatment condition. The “learned helplessness” effect appeared to be no smaller when aversive stimuli were changed between pretreatment and test than when they remained the same.     

The effect of reinforcement probability on time discrimination in the midsession reversal task

We examined how biasing time perception affects choice in a midsession reversal task. Given a simultaneous discrimination between stimuli S1 and S2, with choices of S1 reinforced during the first, but not the second half of the trials, and choices of S2 reinforced during the second, but not the first half of the trials, pigeons show anticipation errors (premature choices of S2) and perseveration errors (belated choices of S1). This suggests that choice depends on timing processes, on predicting when the contingency reverses based on session duration. We exposed 7 pigeons to a midsession reversal task and manipulated the reinforcement rate on each half of the session. Compared to equal reinforcement rates on both halves of the session, when the reinforcement rate on the first half was lower than on the second half, performance showed more anticipation and less perseveration errors, and when the reinforcement rate on the first half was higher than on the second half, performance showed a remarkable reduction of both types of errors. These results suggest that choice depends on both time into the session and the outcome of previous trials. They also challenge current models of timing to integrate local effects.     

Coping patterns in shock anticipation and in everyday stress

Abstract.— GSR patterns were studied in 30 subjects anticipating and receiving electric shocks with high but not definitive probability. Although the majority of subjects showed anticipatory responses, six subjects displayed low or no response during anticipation but very high responses to shocks. As these subjects also reported that during anticipation they tended to deny the possibility of receiving a shock, their response pattern was interpreted as indicating denial of threat, and consequently, little preparation for stress. Self reports about behavior in everyday stress revealed a similar kind of behavior.     

Control motivation and attributions for performance

Two experiments examined the relationship between the desire for effective control over performance outcomes and attributions of causality for those outcomes. In Experiment 1, subjects were led to believe that they had either succeeded at or failed a test that was either unimportant or important. As predicted, failure of the important test was attributed more to lack of effort (a controllable cause) and less to lack of ability (an uncontrollable cause) than was failure of the unimportant test. In Experiment 2, all subjects were led to believe that they had failed a test. Once again, subjects were informed that the test was either important or unimportant. In addition, half the subjects were told that they would be undergoing more tests in a later testing session, while half were not informed of any future testing. As in Experiment 1, subjects failing the important test attributed their failure less to lack of ability than did subjects failing the unimportant test. The anticipation of future testing interacted with test importance in its effects on attributions to ability. Subjects performing the unimportant task attributed their failure more to lack of ability when anticipating future performance than when not. Attributions of subjects performing an important task were not affected by the anticipation of future performance. Results were discussed in terms of the need for control over performance outcomes.     

Anticipation of cognitive demand during decision-making

An abundance of evidence indicates that action selection is guided, at least in certain contexts, by anticipation of action outcomes. In one particularly clear demonstration of this principle, Bechara and colleagues, studying a gambling task, observed phasic skin conductance responses just prior to actions associated with a relatively high risk of monetary loss (Bechara et al. in J Neurosci 19:5473–5481, 1999; Bechara et al. in Science 275:1293–1295, 1997; Bechara et al. in Cereb Cortex 6:215–225, 1996). In the present work, we tested for the same effect in a paradigm where choices resulted not in differential monetary outcomes, but in differential requirements for subsequent mental effort. In two experiments, we observed an anticipatory skin conductance response prior to actions resulting in a high level of cognitive demand. This finding indicates that requirements for effortful cognitive control are anticipated during action selection. We argue, based on convergent evidence, that such anticipation may not only trigger preparation; it may also play a direct role in effort-based decision-making.     

Using memories to motivate future behaviour: An experimental exercise intervention

This study tested a novel memory-based experimental intervention to increase exercise activity. Undergraduate students completed a two-part online survey ostensibly regarding college activity choices. At Time 1, they completed questionnaires that included assessments of exercise-related attitudes, motivation and self-reported behaviours. Next, they described a memory of a positive or negative experience that would increase their motivation to exercise; students in a control condition did not receive a memory prompt. Finally, they rated their intentions to exercise in the future. Eight days following Time 1, students received a Time 2 survey that included an assessment of their self-reported exercise during the prior week. Students in the positive memory condition reported higher levels of subsequent exercise than those in the control condition; students in the negative memory condition reported intermediate levels of exercise. Activating a positive motivational memory had a significant effect on students' self-reported exercise activity even after controlling for prior attitudes, motivation and exercise activity.     

Relations entre le vécu émotionnel et les stratégies d’ajustement en situation de compétition

The purpose of this exploratory study was to deal with the questions of stress and emotions in the sports fields based on transactional theory and reversal theory. Competitive marathon runners (n = 36) completed self-report questionnaires a few hours before and after a marathon. Results highlighted the importance to precompetitive phase in terms of the subjective states of tension–stress, effort–stress, anxiety and excitation. Interesting links were observed between some of these expressions of emotional experience and the performance. It was also demonstrated that the same coping strategy could be associated with pleasant and unpleasant emotions. The limits of this study and the practice perspectives for marathon running will be reviewed in this study.     

The Role of Task Experience and Prior Knowledge for Detecting Invalid Augmented Feedback while Learning a Motor Skill

Two hypotheses were investigated. These were generated from results reported by Buekers, Magill, and Sneyers (1994) and an uncertainty account of those and other effects on skill learning of erroneous knowledge of results (KR). The first hypothesis proposes that if experienced performers have developed the capability of detecting and correcting errors, then they should not be influenced by erroneous KR in the same way as novices. The second proposes that if information about the invalid feedback is given to subjects prior to the beginning of the practice trials, then the capability for assessing feedback can be accelerated such that subjects who receive this advance information should not be misled by the erroneous KR. The first hypothesis was investigated in Experiment 1 by having subjects practise an anticipation timing task for 450 trials. One group received correct KR on all trials, and another group received no KR. Half of the subjects in each group were unexpectedly switched to erroneous KR after 400 trials. Results indicated that the erroneous KR influenced both groups during acquisition and on a retention test one minute later. However, on a retention test given one week later, only the group that had practised with no KR before being switched to erroneous KR continued to show the negative influence of the invalid KR. The second hypothesis was examined in Experiment 2 by telling subjects prior to beginning practice trials that it was possible that the KR they received would be erroneous. Results showed that this intervention strategy was effective on the no-KR retention tests only for subjects who had no-KR trials alternated with trials on which they received the erroneous KR. The results of these experiments provide evidence that uncertainty about the validity of sensory feedback increases the likelihood that subjects will be misled by invalid augmented feedback. Moreover, this uncertainty can be overcome by increased experience or by providing advance knowledge about the nature of the invalid feedback.     

慢性心理应激对大鼠淋巴细胞热休克蛋白70表达和凋亡的影响

为了探讨慢性心理应激对热休克蛋白70（Hsp70）、淋巴细胞的凋亡及其两者之间关系的影响,将实验SD大鼠分为对照组、中等强度心理应激组和高强度心理应激组。分别对三组大鼠给予相应的干预3周,采用流式细胞仪定量检测各组大鼠外周血淋巴细胞Hsp70的表达水平和凋亡量。结果发现,与对照组比较,中等和高强度心理应激组淋巴细胞内Hsp70表达水平显著增加;中等强度心理应激组凋亡量增加但没有出现统计学意义,高强度心理应激组淋巴细胞凋亡显著增加;中等强度心理应激组的淋巴细胞Hsp70表达与凋亡量变化成显著正相关,高强度心理应激组两者变化成不显著正相关。研究结果提示心理应激能诱发淋巴细胞Hsp70表达和凋亡升高,且随心理应激强度增加,Hsp70表达升高趋势减缓、凋亡量增加加剧,最终造成机体免疫损伤加深     

The perception of time following stress

To determine whether the relationship between the overestimation of time and anxiety or stress is a function of the anticipation of the stressful event, high and low socially anxious subjects judged a series of eight short (5-second and 7-second) intervals both prior to and following a stressful or nonstressful social interaction. The results indicated that overestimation of fixed intervals occurs following a stressful interaction, thus disconfirming the hypothesis that such overestimation is due to anticipation of the stressful event. These results are discussed with regard to a modified storage size model of time estimation.     

Correlation between cortisol level and serotonin uptake in patients with chronic stress and depression

In a recent study (Tafet, Toister-Achituv, & Shinitzky, 2001), we demonstrated that cortisol induces an increase in the expression of the gene coding for the serotonin transporter, associated with a subsequent elevation in the uptake of serotonin. This stimulatory effect, produced upon incubation with cortisol in vitro, was observed in peripheral blood lymphocytes from normal subjects. In the present work we investigated the cortisol-induced increase in serotonin uptake in lymphocytes from hypercortisolemic patients, including subjects with major depressive disorder (n = 8), and subjects with generalized anxiety disorder (n = 12), in comparison with a control group of normal healthy subjects (n = 8). A significant increase in serotonin uptake (+37%+14, M + SD) was observed in the control group, whereas neither the generalized anxiety disorder nor the major depression group exhibited changes in serotonin uptake upon incubation with cortisol. It is likely that under chronic stress or depression, the capacity for increase in serotonin transporter has reached its limit due to the chronically elevated blood cortisol level. The physiological and diagnostic implications of this observation are discussed.