Current issues and new directions in Psychology and Health: The costs and benefits of self-regulation – a call for experimental research

Abstract

This study was designed to assess the effects of exercise on psychological functioning in healthy Type A men. Seventy-three middle-aged men (M=42.2 years) were randomly assigned either to an aerobic exercise (AE) training group or to a strength and flexibility (SF) training group. Subjects completed a comprehensive psychological assessment battery prior to beginning the 12-week exercise programs, and after completing the programs. The psychological test battery included measures of depression, anxiety and stress, as well as various psychiatric symptoms. In addition, subjects underwent graded exercise treadmill tests (ETT) at both times of measurement in order to document changes in cardiorespiratory fitness. Aerobic exercise training consisted of walking, jogging or stair-climbing at an intensity of at least 70% of initial measured maximal oxygen consumption (VO₂max determined during the treadmill test). Strength and flexibility training consisted of circuit Nautilus training with no aerobic exercise. Results at the conclusion of the 12-week programs indicated that [Vdot]O₂max for the AE group increased by 15%, while the SF group did not change. Both groups improved on measures of psychological well-being; however, there were no differential effects of the two exercise programs on measures of psychological functioning. These results suggest that improved cardiovascular fitness is not necessary for psychological improvement among exercise participants.     

CATECHOLAMINE EXCRETION, PERFORMANCE, AND SUBJECTIVE STRESS

Psycho-endocrine relations were explored in 52 students exposed to moderately stressful psychological tests demanding selective attention. Subjects with high excretion rates of adrenaline performed better during the entire stress session than did subjects with low adrenaline excretion. The level of subjective stress increased consistently throughout the session in subjects with low excretion rates of adrenaline, while it remained relatively constant in subjects with high adrenaline excretion. No consistent relationship could be demonstrated between noradrenaline excretion and the psychological variables. Possible effects on the catecholamine-excretion patterns of factors such as severity and duration of the stress are discussed.     

Relationships between physiological and psychological stress and salivary immunoglobulin A among young female gymnasts

We investigated whether psychological and physical stress induced by training or competition influence the secretory immune system among 12 highly trained young female gymnasts. Salivary levels of secretory IgA and cortisol responses to gymnastic training session or competition were assessed a total of 10 times, immediately before and after two training sessions which had different intensities and just before and after a major competition. These parameters were also measured on two non-training days. The Brunel Mood Scale was also used to assess the gymnasts's overall mood on each test day. IgA:Protein ratio was calculated. Significant decreases in this ratio were found after each exercise session, related to the physiological and psychological stress induced by exercise. Over the 5-mo. training period the presession IgA:Protein ratios were unchanged. Gymnasts registered any episodes of upper respiratory tract infection. Bouts of exercise induce transitory effects on the immune system in relation to the workload and the stress induced by the exercise without any relation to increased susceptibility to illness in children.     

Intraindividual and interindividual analyses of positive and negative affect: their relation to health complaints, perceived stress, and daily activities

I examined correlates of Negative Affect (NA) and Positive Affect (PA) through both within- and between-subjects analyses. Eighty subjects completed a daily questionnaire for 6-8 weeks. Each day they rated (a) their mood, (b) the extent to which they suffered from various minor physical problems, (c) their level of stress, (d) the time they spent socializing, and (e) whether or not they had exercised. Subjects also completed several trait tests measuring their general affective level, frequency of health problems, and social tendencies. A between-subjects analysis showed the expected pattern: Level of physical complaints and perceived stress were correlated with individual differences in NA but not in PA, whereas social indicators and frequency of exercise were related only to PA. The within-subjects results generally exhibited a similar pattern: Social activity and exercise were more strongly related to PA, whereas perceived stress was highly related to NA. However, the most significant finding was that, contrary to prediction, health complaints were as strongly related to intraindividual fluctuations in PA as in NA. Possible interpretations of the observed correlates of NA and PA are discussed.     

Specific effects of acute moderate exercise on cognitive control

The main issue of this study was to determine whether cognitive control is affected by acute moderate exercise. Twelve participants [4 females (VO_{2 max} = 42 ml/kg/min) and 8 males (VO_{2 max} = 48 ml/kg/min)] performed a Simon task while cycling at a carefully controlled workload intensity corresponding to their individual ventilatory threshold. The distribution-analytical technique and the delta plot analysis [Ridderinkhof, K. R. (2002). Activation and suppression in conflict tasks: Empirical clarification through distributional analyses. In W. Prinz & B. Hommel (Eds.), Common mechanisms in perception and action. Attention and performance (Vol. 19, pp. 494–519). Oxford: Oxford University Press.] were used to assess the role of selective response inhibition in resolving response conflict. Results showed that cognitive processes appeared to be differently affected by acute moderate exercise. Reaction time results confirmed that performance is better (faster without change in accuracy) when the cognitive task is performed simultaneously with exercise. Between-trial adjustments (post-conflict and post-error) highlighted that cognitive control adjustments are also fully efficient during exercise. However, the effect of congruency (Simon effect) appeared to be more pronounced during exercise compared to rest which suggests that the response inhibition is deteriorated during exercise. The present findings suggest that acute moderate exercise differently affects some specific aspects of cognitive functions.     

Does the level of physical exercise affect physiological and psychological responses to psychosocial stress in women?

ObjectivesTo test the Cross-Stressor Adaptation hypothesis for females by examining whether physically exercising young women show reduced physiological and psychological stress responses to a psychosocial stressor.DesignForty-seven healthy young women with different levels of physical exercise (17 not or rarely exercising, 15 moderately exercising, 15 vigorously exercising) underwent the Trier Social Stress Test for Groups (TSST-G); physiological and psychological stress responses during and after stress induction were compared.MethodANOVAs with repeated measures were used to compare stress reactivity and recovery between the three exercise groups. Heart rate and salivary free cortisol were used as indicators of physiological stress response, state anxiety, mood, and calmness as indicators of psychological stress response. For physiological stress reactivity, the areas under the curve with respect to the ground (AUC_G) were compared.ResultsIn all three exercise groups, experimentally induced stress led to a significant rise in heart rate, cortisol, and state anxiety; mood and calmness significantly decreased. As hypothesized, the pattern of the physiological stress response differed for the three exercise groups, with lowered reactivity in the more active groups. However, the psychological stress response partly went in the opposite direction: Exercising participants reported a higher mood decrease, suggesting a dissociation of the physiological and psychological stress responses.ConclusionsThe findings suggest that the Cross-Stressor Adaptation hypothesis is also valid for young women; however, only with regard to physiological stress response. The unexpected findings for psychological stress response need to be further explored in experimental studies.     

Perceived Fitness and Responses to Laboratory Induced Stress

This study sought to evaluate the contribution of perceived physical fitness beyond the contributions of gender, body mass index (BMI), and estimated actual physical fitness on both physiological and self-reported stress responsivity to laboratory induced stress. Seventy-two nonsymptomatic participants participated in the experiment. Participants completed a laboratory procedure measuring cardiovascular responses and self-reported rating of calmness while performing stressful laboratory tasks. Estimated aerobic fitness (VO_{2 max}) as well as perceived fitness were also determined. Perceived fitness significantly contributed to the variance associated with self-reported responses to laboratory stress as well as with some of the physiological measures. Perceived fitness significantly added to the variance beyond that attributed to gender, body mass, and estimated actual physical fitness while assessing systolic blood pressure and calmness. Overall, the results support the view that perception of fitness may be an important factor above and beyond aerobic fitness in its association with responses to stress.     

The Influence of Perceived Versus Aerobic Fitness on Psychological Health and Physiological Stress Responsivity

This study sought to evaluate the association between perceived and aerobic physical fitness and both psychological functioning and physiological stress responsivity. Sixty nonsymptomatic participants (30 males, 30 females) participated in the experiment. Participants completed a series of personality and mood questionnaires as well as a laboratory procedure measuring cardiovascular responses (i.e., heart rate and blood pressure) while performing stressful laboratory tasks (i.e., the Stroop Color Naming Test and a sham IQ test). Aerobic fitness (i.e., VO ₂ max using the Bruce protocol) as well as perceived fitness were also determined. Results suggest that perceived fitness was generally associated with positive personality and mood variables while aerobic fitness was not. Overall results support the view that perception of fitness may be as important or perhaps even more important than aerobic fitness in its association with psychological but perhaps not physical functioning.     

High impact running improves learning

Regular physical exercise improves cognitive functions and lowers the risk for age-related cognitive decline. Since little is known about the nature and the timing of the underlying mechanisms, we probed whether exercise also has immediate beneficial effects on cognition. Learning performance was assessed directly after high impact anaerobic sprints, low impact aerobic running, or a period of rest in 27 healthy subjects in a randomized cross-over design. Dependent variables comprised learning speed as well as immediate (1 week) and long-term (>8 months) overall success in acquiring a novel vocabulary. Peripheral levels of brain-derived neurotrophic factor (BDNF) and catecholamines (dopamine, epinephrine, norepinephrine) were assessed prior to and after the interventions as well as after learning. We found that vocabulary learning was 20 percent faster after intense physical exercise as compared to the other two conditions. This condition also elicited the strongest increases in BDNF and catecholamine levels. More sustained BDNF levels during learning after intense exercise were related to better short-term learning success, whereas absolute dopamine and epinephrine levels were related to better intermediate (dopamine) and long-term (epinephrine) retentions of the novel vocabulary. Thus, BDNF and two of the catecholamines seem to be mediators by which physical exercise improves learning.     

Catecholamine training effects from exercise programs: A bridge to exercise-temperament relationships

Three studies were conducted to test whether a catecholamine training effect results from a long-term aerobic exercise program. Study I showed significant increases in urinary adrenaline and noradrenaline following moderate mental stress/challenge for male aerobics subjects after a semester of training. Control groups of nonexercisers and continuously in-condition marathoners showed no comparable pre- to post semester catecholamine increases. Male and female Aerobics subjects were contrasted with nonexercisers across a semester in Study 2; the hypothesis was confirmed that postsemester increases in catecholamines occurred only following an episode of mental challenges/stress, and not following base-rate-rest conditions. Under conditions of more active challenge than in Studies 1 and 2, women subjects in Study 3 provided directional but nonsignificant support for the Study 2 findings. The results are discussed in the context of literature on the relationship of catecholamine availability during challenge/stress to temperament and on the relationship of aerobic training to temperament. At a theoretical level, the question is discussed of increased catecholamine availability being a likely mediator in the exercise program to temperament relationship.This research was supported by a grant from the Research Council of the University of Nebraska Lincoln. Our thanks to Prof. James Crabbe for assistance in recruiting subjects in Study 2, and to Pamela Brown and Prof. Wes Sime for assistance with Study 3.     

Teacher stress over an autumn term: relationships between subjective stress and catecholamine excretion during night rest

The relationships between subjective stress and catecholamine excretion during night rest were investigated in a group of 137 teachers. The research design was longitudinal and consisted of repeated assessment (six times in an autumn term) of the stress indicators. At the beginning of the term adrenaline excretion rate showed negative and at the end of the term positive correlations with subjective stress feelings. Cluster analysis revealed three stable profile types among the teachers, in which the stress indicators were related to each other in different ways. The subjective stress process was better reflected in noradrenaline excretion than in adrenaline excretion. The findings were interpreted to reflect the changes in the intensity of emotional arousal during the term.     

Night-rest urinary catecholamine excretion in relation to aspects of free time, work and background data in a teacher group

Free time, work and background data were related to night-rest catecholamine excretion rates in a teacher group (n = 137) during an autumn term. The explained interindividual variance increased slightly towards the end of the term. Adrenaline excretion was predicted better than noradrenaline, notedly by coffee consumption, amount of physical activity, and subjective stress feelings which explained 16% of the variance in adrenaline excretion during night rest. However, the results indicated that the differences in catecholamine excretion during night rest remained mostly unpredictable.     

The influence of gender, hypertension risk, and aerobic fitness on cardiovascular responses to laboratory-induced stress

The study sought to evaluate the influence of gender, hypertension risk, and aerobic fitness on cardiovascular responses to laboratory-induced stress. Sixty nonsymptomatic subjects (30 males, 30 females) participated in the experiment. Half of the subjects had at least one biological parent with hypertension, while half had no parental history of hypertension and served as comparison subjects. Subjects completed a laboratory procedure measuring cardiovascular responses (i.e., pulse rate and blood pressure) while performing stressful laboratory tasks (i.e., the Stroop Color Naming Test and a sham IQ test). Aerobic fitness (i.e., VO_2max using the Bruce protocol) was also determined using a submaximal treadmill test in the laboratory. Results suggest that males with a family history of hypertension were more stress responsive based on systolic blood pressure, while females were more stress-responsive according to pulse rate activity. Fitness levels were significantly associated with diastolic blood pressure throughout the stress and recovery periods but were unrelated to pulse rate and systolic blood pressure.     

Role of physical activity and perceived adequacy on peak aerobic power in children with developmental coordination disorder

The purpose of this study was to determine the mediating role of physical activity and perceived adequacy towards physical activity on peak aerobic power (VO₂peak) in children with developmental coordination disorder. This case-control study involved 61 male and female subjects age 12-13 years with motor impairments and 61 healthy controls matched for age, gender and school location. Subjects were assessed for motor proficiency and classified as probable developmental coordination disorder (p-DCD) or healthy control using the Movement Assessment Battery for Children, 2nd Edition. VO₂peak was assessed by a progressive exercise test on a cycle ergometer. Perceived adequacy towards physical activity was estimated using the Children’s Self-perception of Adequacy and Predilection for Physical Activity scale. Physical activity was monitored for seven days using accelerometry. Children with p-DCD had significantly lower VO₂peak adjusted for lean mass (48.8 ± 7.2 ml/kg LM/min; p ? 0.05) compared to controls (53.1 ± 8.2 ml/kg LM/min). Regression analysis demonstrated that perceived adequacy and physical activity were significant mediators in the relationship between p-DCD and VO₂peak (R-squared = 24.3%). In conclusion, using a stringent laboratory assessment, the current study verifies earlier non laboratory findings, adding low aerobic power, the most important component of cardiorespiratory fitness, to the list of health consequences associated with developmental coordination disorder.     

Perceived Fitness Predicts Daily Coping Better Than Physical Activity or Aerobic Fitness

This study sought to evaluate the association between perceived physical fitness, actual fitness measured by VO₂max, daily physical activity measured by an ambulatory activity monitor, and coping with daily stress. One hundred and thirty participants completed a series of questionnaires measuring perceived fitness as well as daily stress and coping levels each day for one week. Participants were also provided with a digital physical activity monitor (Yamax Digi-Walker SW 200) and instructed to wear it throughout the seven day assessment period. Upon completion of the week evaluation, participants then were evaluated for actual physical fitness by treadmill testing. Multiple regression and effect size analysis revealed that perceived fitness predicted daily coping better than actual fitness and daily physical activity. Coping was unrelated to age, gender,VO₂max, and physical activity. Results suggest that perceived fitness may be a better predictor of coping with daily stress than actual physical fitness or physical activity.     

Effect of acute aerobic exercise on cognitive performance: Role of cardiovascular fitness

ObjectivesTo determine whether fitness and cognitive task type moderate the relationship between acute exercise and cognition.MethodsThirty-six healthy college-aged adults completed a maximal graded exercise test and were categorized as low, moderate, or high in cardiovascular fitness. Participants then performed the Stroop Test prior to and after an acute bout of cycling exercise that consisted of a 5-min warm-up, 20 min of exercise at moderate intensity (65% VO_2max), and a 5-min cool-down.ResultsIndividuals of all fitness levels improved in cognitive performance following exercise. With regards to fitness, while no differences were observed on the congruent condition as a function of fitness, high fit individuals showed the longest response time on the Stroop incongruent condition.ConclusionThe beneficial relationship between performance of an acute bout of exercise and cognitive performance were observed for both cognitive task types and for participants of all fitness levels. However, a curvilinear relationship was observed between fitness and cognitive task type performance such that participants who were moderately fit performed the best on the incongruent trials, implying that maintaining fitness at a moderate level is associated with better executive function.     

Similar improvements in inhibitory control following low-volume high-intensity interval exercise and moderate-intensity continuous exercise

ObjectivesWe previously demonstrated that a traditional high-volume (HV) high-intensity interval exercise (HIIE) was more effective in improving post-exercise inhibitory control (IC) than moderate-intensity continuous exercise (MCE). Nevertheless, because HV-HIIE is performed with a higher volume and longer duration, it may result in decreased adherence to this exercise for some individuals. In this study, we compared the effect of a practical low-volume (LV) HIIE to that of MCE on post-exercise IC improvements.DesignTwenty healthy males performed both LV-HIIE and MCE on a cycle ergometer in a crossover design.MethodLV-HIIE was consisted of ten 1-min bouts at 90% of the peak oxygen consumption (VO_{2 peak}) with 1-min active recovery at 30% of VO_{2 peak}, which had a total duration of 20 min. MCE was performed for 40 min at 60% of VO_{2 peak}. To evaluate IC, the Stroop test was administered before exercise, immediately after exercise, and every 10 min during the 30-min post-exercise recovery period.ResultsIC significantly improved immediately after LV-HIIE and MCE compared with that before each exercise (both Ps < 0.05). The improved IC remained significant until the 20-min post-exercise recovery period for both protocols (all Ps < 0.05). The degrees of post-exercise IC improvements throughout the 30-min post-exercise recovery period did not differ significantly between protocols.ConclusionsThese findings demonstrated that despite lower exercise volume and shorter exercise duration, LV-HIIE could improve post-exercise IC similar to MCE.     

Acute aerobic exercise improves memory across intensity and fitness levels

ABSTRACT

The present study was designed to examine the impact of exercise intensity and aerobic fitness on free recall, judgments of learning (JOLs), and metacognitive accuracy. In Experiment 1, 30 college students engaged in either (1) no exercise, (2) light exercise (55% of predicted maximal heart rate), or (3) moderate exercise (75% of predicted maximal heart rate) on three different days. In Experiment 2, 29 high-fit students (VO₂ max?≥?70th percentile) and 28 low-fit students (VO₂ max?≤?50th percentile) completed sedentary and light exercise conditions. In both experiments, free recall scores significantly increased in the exercise conditions compared with the sedentary condition, but JOL magnitude and metacognitive accuracy were largely unaffected. These results demonstrate that exercise can improve recall at both light and high intensities, and that the benefit can be obtained by individuals regardless of their fitness level.     

Catecholamine excretion in pleasant and unpleasant situations

Catecholamine excretion was studied in 36 students under four different conditions, which involved either playing a game of chance, performing psychological tests, watching surgical films or spending the session in inactivity. Adrenaline excretion was shown to be highest during the game session, which was described by the subjects in the most positive terms. It was concluded that a rise in behavioural arousal level is accompanied by increased adrenaline secretion, also when the arousal increase is induced by a situation regarded as pleasant.     

Effort and negative affect interact to predict cardiovascular responses to stress

Objective: Although traditional models posit that negative emotional responses to stress increase cardiovascular reactivity (CVR), laboratory studies have generally not found a strong emotion–CVR association. In this paper, we took a multidimensional approach to examining psychological reactions to stress in three studies.

Methods: In each study we assessed the amount of effort exerted by a participant and the negative affect (NA) felt by the participant with different self-reported measures and an effort behavioural measure.

Results: Our findings consistently demonstrated that NA was associated with CVR when effort was relatively high, but not when effort was relatively low.

Conclusion: This suggests that the weak NA–CVR correlations reported in past research may have been confounded by a third effort-related variable and that CVR is significantly associated with NA under certain circumstances. Furthermore, our findings suggest that by considering the multidimensional nature of psychological responses to stress, we may come to better understand the links between stress-related emotion and physiology.