Subjective Fatigue Level Research Articles

At home and away: Measuring the sleep of Australian truck drivers

The causes of fatigue in truck drivers related to work hours have been studied extensively and are reasonably well understood. However, much less is known about how rest opportunities can be structured to optimise recovery from fatigue. The nature of the road transport industry often requires that rest be taken in various locations. New investigation in this area, focusing on sleep obtained in truck cabs and other non-home environments is critically important to complement existing understanding. This study examined sleep at home and in truck cabs, in truck drivers who were actively working during the time of the study. Thirty-seven male drivers aged between 24 and 63 years (age: 48.7 ± 9.0 years; mean ± SD) wore activity monitors (also known as ‘sleep watches’) and completed work and sleep diaries for a period of 21 days, recording their subjective fatigue levels before, during and after work shifts, and before and after sleep periods. They also self-rated their sleep quality and noted the number of times they woke during sleep periods. Analyses focused on home versus in-truck sleep periods. The subjective data suggested that a greater quantity ( P < .001) and quality ( P < .05) of sleep was obtained at home than in the truck, and that sleeping at home more effectively reduced fatigue levels ( P < .001). The objective data showed trends towards longer sleep length at home, but other variables, including total sleep per 24 h and sleep quality, showed no significant differences. This study demonstrates that measuring sleep quantity and quality in operational road transport environments is feasible. The findings caution against over-reliance on laboratory and simulator studies since there are critical aspects of the operating environment that cannot be validly studied in artificially controlled settings. This study is unique in its direct examination of sleep quantity and quality in truck drivers sleeping at home and away from home.

La fatigue dans la dystrophie myotonique de Steinert : revue de la littérature et voies de recherche

Steinert myotonic dystrophy is one of the most frequent adult hereditary myopathies. Literature on fatigue showed how relevant this trouble could be for a majority of patients; and also how specific fatigue could be in Steinert disease, compared to other neuromuscular pathologies: in myotonic dystrophy, fatigue and somnolence are two distinct phenomena; the link between fatigue and pain is not significant; there is no correlation between perceived physical activity and actual physical activity, neither between actual physical activity nor subjective fatigue. Thus, more than in any other muscular diseases, factors that are not purely physical seem to be involved in fatigue felt by patients with Steinert disease. ObjectivesTo better apprehend factors that may be involved in subjective fatigue in Steinert disease. MethodWe have examined literature about other affections for which fatigue were richly documented. Fatigue in Chronic Fatigue Syndrome, Parkinson's disease, Multiple Sclerosis, Alzheimer's disease, Poliomyelitis and Myasthenia is studied. Physical, mental and subjective fatigues are well known different types of fatigue. However, clinically, it seems inefficient to try to understand those concepts separately, since they are highly intricate. ResultsFrom this literature review, we underlie three possible etiologies of fatigue experienced by subjects with Steinert's pathology. 1) Central nervous system, in some degrees of alteration, could lead to an objective reduction of the cognitive and physical endurance abilities and to an accurate perception of these perturbations, which result in objective and subjective fatigues, which are highly correlated. We call it “central fatigue”. 2) The functional handicap requires, from an individual, abnormal muscular efforts and important sustained attention (to avoid falls, and/or to anticipate any leisure activity), leading to both physical and mental fatigues. These fatigues would be more or less intense, depending on adaptative strategies engaged by the individual (socially active or not), this is why we call it “adaptative fatigue”. 3) Psychological distress and fatigue could coexist, and/or maintain one and each other. Fatigue is one of the depression symptoms. But depressed subjects would have a tendency to “over-underestimate” their actual physical and cognitive limitations, leading to a subjective fatigue complaint, which is not correlated with objective physical or cognitive fatigue anymore. Anxiety, as a “hyper-vigilance state”, would create a state of mental draining, and would exhaust the cognitive abilities, leading to high level of subjective fatigue. We call it “secondary fatigue”. ConclusionOur aim now remains in designing a future research, in which we would methodologically study these three factors of fatigue, in adults with Steinert's myotonic dystrophy.

Trunk Extensor Muscle Fatigue Does Not Affect Postural Control during Upright Static Stance in Young-adults and Middle-aged Adults

Background. Falls can be extremely detrimental to someone’s daily living, as well as life threatening This is especially true for individuals who have back problems, are sedentary, and have other health disorders. The purpose of this study was to investigate the effect of trunk extensor muscles fatigue on static postural control in young healthy adults compared to middle aged subjects. Methods. University students (n=10), and Middle-aged subjects (n=6; 40+ years of age) stood as immobile as possible on a force plate, with their feet together and eyes closed under two conditions; Fatigue and No fatigue. Fatigue was achieved through repetitive extensions of the trunk until a subjective fatigue level was reached. We measured center of pressure (CoP) displacements in the A/P and M/L planes using a force plate to assess standing balance. Findings. We did not observe any significant interaction between age and fatigue indicating that fatigue affected both age groups similarly. The CoP variability was higher for the middle aged compared to the young adults in both the fatigue and no-fatigue conditions. Interpretation. The results of this study indicate that trunk extensor fatigue does not affect balance differently for young compared to middle-aged subjects. This study also suggests that postural control decreases significantly with increasing age. Our finding that trunk extensor fatigue did not significantly affect the postural control of upright stance contradicts previous studies; this difference may be due to the subject sample in our study.

The diagnostic value of endothelial function as a potential sensor of fatigue in health

Many epidemiological research studies have shown that vital exhaustion and psychosocial factors are associated with the occurrence of cerebrocardiovascular disease (CCVD). Fatigue is thought to induce endothelial dysfunction and may be linked to the occurrence of CCVD; however, no studies have investigated this potential link. We studied to determine the effect of fatigue on endothelial function in healthy subjects with no traditional CCVD risk factors or potential confounding factors to be controlled. Peripheral arterial tonometry (PAT) was used to evaluate endothelial function. The influence of the following parameters on endothelial function was analyzed in 74 office workers without traditional CCVD risk factors at health check-ups: endothelial function before and after work, subjective fatigue, lifestyle factors such as sleeping time, and psychosocial factors such as depression and social support. Twenty-five subjects (33.8%) had low endothelial function; reactive hyperemia (RH)-PAT index <1.67, even though no abnormalities were reported in the health check-ups. There was no significant difference in endothelial function before versus after labor. Of note, endothelial function was associated with the individual's level of subjective fatigue (t = 2.98, P = 0.008) and showed a daily fluctuation, sometimes to a pathological degree (<1.67). We showed that, even in healthy people, endothelial function fluctuates diurnally, with an interaction between the individual's cognitive fatigue and the environment, sometimes to a pathological degree. Based on these findings, we suggest that endothelial function is an objective assessment tool of fatigue in healthy individuals.

Quantitative physiologically based modeling of subjective fatigue during sleep deprivation

A quantitative physiologically based model of the sleep–wake switch is used to predict variations in subjective fatigue-related measures during total sleep deprivation. The model includes the mutual inhibition of the sleep-active neurons in the hypothalamic ventrolateral preoptic area (VLPO) and the wake-active monoaminergic brainstem populations (MA), as well as circadian and homeostatic drives. We simulate sleep deprivation by introducing a drive to the MA, which we call wake effort, to maintain the system in a wakeful state. Physiologically this drive is proposed to be afferent from the cortex or the orexin group of the lateral hypothalamus. It is hypothesized that the need to exert this effort to maintain wakefulness at high homeostatic sleep pressure correlates with subjective fatigue levels. The model's output indeed exhibits good agreement with existing clinical time series of subjective fatigue-related measures, supporting this hypothesis. Subjective fatigue, adrenaline, and body temperature variations during two 72 h sleep deprivation protocols are reproduced by the model. By distinguishing a motivation-dependent orexinergic contribution to the wake-effort drive, the model can be extended to interpret variation in performance levels during sleep deprivation in a way that is qualitatively consistent with existing, clinically derived results. The example of sleep deprivation thus demonstrates the ability of physiologically based sleep modeling to predict psychological measures from the underlying physiological interactions that produce them.

Ego depletion and the strength model of self-control: A meta-analysis.

According to the strength model, self-control is a finite resource that determines capacity for effortful control over dominant responses and, once expended, leads to impaired self-control task performance, known as ego depletion. A meta-analysis of 83 studies tested the effect of ego depletion on task performance and related outcomes, alternative explanations and moderators of the effect, and additional strength model hypotheses. Results revealed a significant effect of ego depletion on self-control task performance. Significant effect sizes were found for ego depletion on effort, perceived difficulty, negative affect, subjective fatigue, and blood glucose levels. Small, nonsignificant effects were found for positive affect and self-efficacy. Moderator analyses indicated minimal variation in the effect across sphere of depleting and dependent task, frequently used depleting and dependent tasks, presentation of tasks as single or separate experiments, type of dependent measure and control condition task, and source laboratory. The effect size was moderated by depleting task duration, task presentation by the same or different experimenters, intertask interim period, dependent task complexity, and use of dependent tasks in the choice and volition and cognitive spheres. Motivational incentives, training on self-control tasks, and glucose supplementation promoted better self-control in ego-depleted samples. Expecting further acts of self-control exacerbated the effect. Findings provide preliminary support for the ego-depletion effect and strength model hypotheses. Support for motivation and fatigue as alternative explanations for ego depletion indicate a need to integrate the strength model with other theories. Findings provide impetus for future investigation testing additional hypotheses and mechanisms of the ego-depletion effect.

Evaluation of mental fatigue based on multipsychophysiological parameters and kernel learning algorithms

Mental fatigue is an extremely sophisticated phenomenon, which is influenced by the environment, the state of health, vitality and the capability of recovery. A single parameter cannot fully describe it. In this paper, the effects of long time sustained low-workload visual display terminal (VDT) task on psychology are investigated by subjective self-reporting measures. Then power spectral indices of HRV, the P300 components based on visual oddball and wavelet packet parameters of EEG are combined to analyze the impacts of prolonged visual display terminal (VDT) activity on autonomic nervous system and central nervous system. Finally, wavelet packet parameters of EEG are extracted as the features of brain activity in different mental fatigue states. Kernel principal component analysis (KPCA) and support vector machine (SVM) are jointly applied to differentiate two states. The statistic results show that the level of both subjective sleepiness and fatigue increase significantly from pre-task to post-task, which indicate that the long time VDT task induces the mental fatigue to the subjects. The predominant activity of autonomic nervous system of subjects turns to the sympathetic activity from parasympathetic activity after the task. The P300 components and wavelet packet parameters of EEG are strongly related with mental fatigue. Moreover, the joint KPCA-SVM method is able to effectively reduce the dimensionality of the feature vectors, speed up the convergence in the training of SVM and achieve a high recognition accuracy (87%) of mental fatigue state. Multipsychophysiological measures and KPCA-SVM method could be a promising tool for the evaluation of mental fatigue.

Physical Training in Children with Osteogenesis Imperfecta

To study the effects of a physical training program on exercise capacity, muscle force, and subjective fatigue levels in patients with mild to moderate forms of osteogenesis imperfecta (OI). Thirty-four children with OI type I or IV were randomly assigned to either a 12-week graded exercise program or care as usual for 3 months. Exercise capacity and muscle force were studied; subjective fatigue, perceived competence, and health-related quality of life were secondary outcomes. All outcomes were measured at baseline (T = 0), after intervention (T = 1), and after 6 and 9 months (T = 2 and T = 3, respectively). After intervention (T = 1), peak oxygen consumption (VO2peak), relative VO2peak (VO2peak/kg), maximal working capacity (Wmax), and muscle force were significantly improved (17%, 18%, 10%, and 12%, respectively) compared with control values. Subjective fatigue decreased borderline statistically significantly. Follow-up at T = 2 showed a significant decrease of the improvements measured at T = 1 of VO2peak, but VO2peak/kg, Wmax, and subjective fatigue showed no significant difference. At T = 3, we found a further decrease of the gained improvements. A supervised training program can improve aerobic capacity and muscle force and reduces levels of subjective fatigue in children with OI type I and IV in a safe and effective manner.

The relationship between subjective fatigue and cognitive fatigue in advanced multiple sclerosis

The present study examined the cognitive performance and ratings of subjective fatigue in people with advanced MS and matched healthy control participants. A continuous n-back task, involving attention (0-back), was performed at the beginning and end of one testing session; a task involving working memory (1-back) was performed at the beginning and end of another testing session. Subjective fatigue was rated at regular intervals during each session. Overall, there was limited evidence of objective cognitive fatigue in the MS group, as assessed by the change in n-back performance during the sessions. The MS group did report a greater increase, than the control group, in the level of subjective fatigue during the 1-back testing session, but change in subjective fatigue did not correlate significantly with change in cognitive performance. The implications of these findings for our understanding of cognitive fatigue in MS are discussed.

Symptom Change With Exercise Is a Temporary Phenomenon for People With Multiple Sclerosis

Smith RM, Adeney-Steel M, Fulcher G, Longley WA. Symptom change with exercise is a temporary phenomenon for people with multiple sclerosis. Objective To determine the impact of a single exercise session on function, fatigue, and sensory symptoms for people with multiple sclerosis (MS). Design This pilot study was designed as a before-after trial. Demographic and response-to-exercise measures were taken before exercise, repeated immediately after exercise, and followed up again 24 hours later. Setting Three metropolitan centers of an MS society. Participants A prospective sample of 34 subjects with MS who were referred for physiotherapy for an exercise program and who could attend an MS society center. Interventions Subjects performed an individually prescribed exercise session, which was at a commencement level and included strengthening, stretches, and fitness exercises. Subjects exercised for between 5 to 45 minutes (mean, 17.4min) at an intensity of 7 to 17 (median, 12) on the Borg rating of perceived exertion (RPE) scale. Main Outcome Measures All outcome measures were self-rated by subjects and included the Borg RPE scale, a questionnaire for sensory symptom description, and visual analog scales for rating of fatigue, function, and intensity of sensory symptoms. Results Subjective levels of fatigue and function immediately postexercise and 24 hours postexercise did not differ significantly from pre-exercise levels. However, over 40% of subjects experienced a temporary increase in number of sensory symptoms, 44% experienced an increase in the intensity of sensory symptoms, and 29% experienced an increase in both number and intensity immediately postexercise. Conclusions This small study found that when people with MS undertake exercise at a commencement level, they can expect that sensory symptoms may change temporarily, but they are unlikely to have any deleterious changes in fatigue and function.

Effects of mental fatigue on attention: An ERP study

The effects of mental fatigue on attention were assessed. Subjects performed a visual attention task for 3 h without rest. Subjective levels of fatigue, performance measures and EEG were recorded. Subjective fatigue ratings, as well as theta and lower-alpha EEG band power increased, suggesting that the 3 h of task performance resulted in an increase in fatigue. Reaction times, misses and false alarms increased with time on task, indicating decreased performance efficiency in fatigued subjects. Subjects were unable to inhibit automatic shifting of attention to irrelevant stimuli, reflected by a larger negativity in the N1 latency range for irrelevant, compared to relevant stimuli. This difference in negativity was unaffected by time on task. However, N1 and N2b amplitude did change with time on task: N1 amplitude decreased, and the difference in N2b amplitude between relevant and irrelevant stimuli (larger N2b amplitude evoked by relevant stimuli) decreased with time on task. The results indicate a dissociation in the effects of mental fatigue on goal-directed (top–down) and stimulus-driven (bottom–up) attention: mental fatigue results in a reduction in goal-directed attention, leaving subjects performing in a more stimulus-driven fashion.

The Effect of Mindfulness Training on Mood and Measures of Fatigue, Activity, and Quality of Life in Patients with Chronic Fatigue Syndrome on a Hospital Waiting List: A Series of Exploratory Studies

Three exploratory studies evaluated group mindfulness training (which aims to facilitate non-judgmental attention to present moment experience through the practice of meditation) in patients waiting for cognitive behaviour therapy for Chronic Fatigue Syndrome (CFS). The approaches used were based on Mindfulness Based Stress Reduction, and Mindfulness Based Cognitive Therapy. The first group showed that such training is acceptable to patients and that it results in significantly improved subjective measures of anxiety, and improvements in subjective levels of fatigue that approached significance, when compared to waiting list controls. A second uncontrolled study replicated the findings of the first study and also demonstrated an improvement in quality of life as measured by the Fatigue Impact Scale (FIS). More wide-ranging effects were demonstrated in the final study in which significant improvements in subjective levels of fatigue, anxiety, depression, quality of life and physical functioning were observed following the training programme. These effects were sustained for 3 months. Overall, the findings of the three exploratory studies indicate that MBSR/MBCT has potential for the treatment of patients with CFS.

Effect of monitor luminance and ambient light on observer performance in soft-copy reading of digital chest radiographs.

To examine the combined effects of monitor luminance and ambient light on observer performance for detecting abnormalities in a soft-copy interpretation of digital chest radiographs. A total of 254 digital chest radiographs were displayed on a high-resolution cathode ray tube monitor at three luminance levels (25, 50, and 100 foot-lamberts) under three ambient light levels (0, 50, and 460 lux). Six chest radiologists reviewed each image in nine modes of combined luminance and ambient light. The observers were allowed to adjust the window width and level of the soft-copy images. The abnormalities included nodule, pneumothorax, and interstitial disease. Observer performance was analyzed in terms of the receiver operating characteristics. The observers reported their subjective level of visual fatigue with each viewing mode. A statistical test was conducted for each of the abnormalities and for fatigue score by using repeated-measures two-way analysis of variance with an interaction. The detection of nodules was the only reading that was affected by the ambient light with a statistically significant difference (P <.05). Otherwise, observer performance for detecting a nodule, pneumothorax, and interstitial disease was not significantly different in the nine-mode comparison. There was no evidence that the luminance of the monitors was related to the ambient light for any of the abnormalities. The fatigue score showed a statistically significant difference due to both the luminance and ambient light. When adequate window width and level are applied to soft-copy images, the primary diagnosis with chest radiographs on the monitor is unlikely to be affected under low ambient light and a monitor luminance of 25 foot-lamberts or more.

Effect of prolonged free-walking fatigue on gait and physiological rhythm

This study examined the ways in which gait patterns and physiological rhythms such as those of muscle activity (tibialis anterior (TA) and biceps femoris (BF)) and cardiac activity are affected by the fatigue induced by prolonged free walking. Twelve normal subjects who walked for 3 h at their preferred pace were divided into two groups according to whether their mean gait cycle time (reciprocal of stride rate) during the second 90 min was higher (Group A: n=8) or lower (Group B: n=4) than that during the first 90 min. For Group A, the level of subjective fatigue during the walking task was significantly higher and the heart rate at rest was significantly lower than Group B. In Group A, prolonged walking significantly decreased the mean power frequency of the electromyography from TA, increased the variability of gait rhythm, decreased the largest Lyapunov exponent of the vertical component of back-waist acceleration, and decreased the amplitude of the vertical component of back-waist acceleration. Taking the onset timings of these changes into account, we propose that subjects who tire easily during prolonged walking first show local muscle fatigue at TA followed by instability of gait rhythm and then they slow their gait rhythm to enhance local dynamic stability. For both groups we constructed a physical fatigue index described by linear regression of gait and physiological variables. When we compared the subjective fatigue level with the fatigue level predicted using the index, we obtained a relatively high correlation coefficient for both groups ( r=0.77).

The impact of a nap opportunity during the night shift on the performance and alertness of 12-h shift workers.

The purpose of this workplace evaluation was to assess the effects on performance, alertness and subsequent sleep of strategic napping on 12-h overnight shifts. In a counterbalanced crossover design, 24 male aircraft maintenance engineers working in a forward rotating 12-h shift pattern volunteered to take part in the study for two work weeks. During the experimental week, each subject was given the opportunity to take a 20-min nap at work between 01:00 and 03:00 h on each of their two overnight shifts. On the control week no naps were taken on the night shifts. A computerized neurobehavioural test battery was employed to assess performance and subjective levels of fatigue at the beginning and end of each night shift, and pre- and postnap. Subjects were also asked to rate how near they had come to falling asleep while driving to and from work. The results revealed that taking a single 20-min nap during the first night shift significantly improved speed of response on a vigilance task measured at the end of the shift compared with the control condition. On the second night shift there was no effect of the nap on performance. Taking a short nap during either night shift had no significant effect on subjective ratings of fatigue, the level of sleepiness reported while driving to and from work, or subsequent sleep duration and sleep quality. Overall the results suggest some promise for a short duration nap taken in the workplace to counteract performance deficits associated with the first night shift.

The impact of hemoglobin levels on fatigue and quality of life in cancer patients

BackgroundAlthough fatigue is a commonly reported symptom in cancer patients its etiology is still poorly understood. The objective of the present study was to investigate the relationship between hemoglobin (Hb) levels and the subjective experience of fatigue and quality of life in cancer patients with mild or no anemia undergoing chemotherapy. Patients and methodsSixty-eight cancer patients (25 colorectal, 26 lung and 17 ovarian cancer) presently undergoing chemotherapy participated in the study. Fatigue was measured with the Multidimesional Fatigue Inventory (MFI-20), quality of life with The European Organization for Research and Treatment of Cancer QLQ-C30. In order to provide normative data for fatigue levels, the MFI-20 was also completed by a sex- and age-matched sample of 120 healthy controls. ResultsCompared with healthy subjects, cancer patients experienced significantly higher levels of subjective fatigue. Correlations between Hb values and subscales of the MFI-20 were moderate with a tendency to increase during chemotherapy. Hb values alone, however, do not fully account for the observed fatigue. Other symptoms, especially pain, dyspnea and sleep disturbances, also showed an association with perceived fatigue. ConclusionsDespite significant correlations, these results indicate that Hb values only partially explain subjectively experienced fatigue and quality of life in cancer patients. It is suggested therefore that the treatment of fatigue must be multidimensional and involve all areas which contribute to the syndrome.

ニューラルネットワークによる心拍情報からの主観的疲労感推定の提案

ニューラルネットワークによる心拍情報からの主観的疲労感推定の提案

Development of fatigue symptoms during simulated driving

Why do people sometimes allow themselves to be overcome by fatigue? Ancient human survival may have depended on ignoring fatigue. Its modern occurrence in the absence of strain may further render us insensitive to its warning value. To test whether deliberate monitoring of certain symptoms may help drivers and other workers realize when they need to rest to avoid hazard, the development of fatigue while driving a simulator was objectively measured in terms of how many persons quit driving as a function of time. Some subjects asked to stop after 90 minutes; others lasted 240 minutes. Grouping data from an adapted Pearson [(1957) Journal of Applied Psychology, 44, 186–191] fatigue checklist revealed a curious phenomenon. No matter how long subjects drove before wanting to quit, they still developed much the same subjective level of fatigue at the end. This suggests that people do not differ greatly in how much fatigue they can tolerate but rather how quickly they reach a certain critical level of fatigue. Averaging fatigue scores backwards from the time subjects quit produced a function similar to the quitting function. Similar treatment of the other data revealed certain clusters of symptoms whose development also paralleled the development of fatigue.

２音融合値による疲労の測定と分析 特にフリッカー値と比較して

According to the acoustical method introduce here, a pair of pure tones, of 2 kHz with a duration of 20 msec, was given repeatedly as acoustical stimuli. The interval of the two tones was changed stepwisely to determine the threshold, Tm, of acoustical fusion of the two tones. Simultaneously, the traditional optical flicker fusion technique was used to determine the corresopnding threshold, Fm. Then, Tm was examined whether it could be utilized to measure fatigue. The following three kind of experiments were carried out: 1) Tm showed a reasonable diurnal change, which was just in the counter phase of that of Fm. 2) A questionnaire survey about various factors ascribable to subjective fatigue in daily activities was conducted, and made measurement and analysis of these various factors of fatigue including Tm and Fm. (a) The weights of the factors contributing to Tm and Fm was assessed by Hayashi's Quantification Theory (I). The result showed that Fm was determined chiefly by the major activity of the day, the type of drinks taken just before the measurement, and the degree of waking level, while Tm tended to be determined by the day of the week, weather conditions, etc. also, it was found that both of Fm and Tm were determined similarly by the activity prior to measurement, the subjective fatigue level, and the time of measurement. (b) The weights of factors contributing to subjective fatigue was determined by Hayashi's Quantification Theory (II). The result showed that the subjective fatigue was mainly determined by the degree of waking level, Tm, the activity prior to the measurement, and Fm. 3) Fm and Tm were changed by VDT workload. Fm was changed in the negative direction, while Tm was changed in the positive. Thus, it may be concluded that Tm is acceptable as a indicator of work-indused fatigue.

Hard-driving and speed-impatience components of the type A behavior pattern as predictors of physiological arousal, subjective arousal and challenge seeking

Male and female subjects first worked on a cognitive task under conditions of either low or high challenge followed by a physical exercise task. Heart rate, systolic blood pressure, diastolic blood pressure, subjective arousal, subjective fatigue, and preferred levels of challenge for subsequent tasks were assessed. The results indicated that subjects with high Hard-Driving scores reported lower subjective arousal while working on the cognitive tasks and preferred to work on more challenging cognitive and physical exercise tasks in a subsequent phase of the experiment. In contrast, subjects with high Hard-Driving scores, high Speed-Impatience scores, or high overall Type A scores did not evidence higher physiological arousal in response to either the cognitive or the physical exercise tasks. Utilization of the components of the Type A pattern yielded greater specificity of results and suggests that Type A's are at greater risk from coronary disease for reasons other than those that have been traditionally hypothesized.