Treadmill Exercise Alleviates Brain Iron Dyshomeostasis Accelerating Neuronal Amyloid-β Production, Neuronal Cell Death, and Cognitive Impairment in Transgenic Mice Model of Alzheimer's Disease

Brain iron increases with age and abnormal brain iron metabolism is proving increasingly likely to be involved in the pathology of Alzheimer's disease (AD). The iron-regulatory effect of furin, a ubiquitously expressed proconvertase, might play an important role in AD. Therefore, there is an urgent need to study the effect of furin on iron regulation in AD. For that purpose, we aimed to determine the role of physical exercise in AD associated with brain iron dyshomeostasis. Treadmill exercise attenuated the AD-related abnormal brain iron regulation by furin in vivo, as demonstrated via experiments in aged APP-C105 mice. Next, we examined whether treadmill exercise decreases excessive iron, directly affecting amyloid-β (Aβ) production through the regulation of α-secretase-dependent processing of amyloid protein precursor (APP) involved in the modulation of furin activity. We first observed that cognitive decline and Aβ-induced neuronal cell death were induced by disruption of APP processing via excess iron-induced disruption of furin activity in aged APP-C105 mice. The induced cognitive decline and cell death were attenuated by treadmill exercise. This result suggests that treadmill exercise alleviated cognitive decline and Aβ-induced neuronal cell death by promoting α-secretase-dependent processing of APP through low iron-induced enhancement of furin activity. This is concomitant with decreasing levels of lipid peroxidation products and promoting antioxidant defense enzyme capacities. Therefore, iron-targeted therapeutic strategies involving treadmill exercise might be useful for patients with AD.

Moderate Intensity Treadmill Exercise Increases Survival of Newborn Hippocampal Neurons and Improves Neurobehavioral Outcomes after Traumatic Brain Injury

Physician-prescribed rest after traumatic brain injury (TBI) is both commonplace and an increasingly scrutinized approach to TBI treatment. Although this practice remains a standard of patient care for TBI, research of patient outcomes reveals little to no benefit of prescribed rest after TBI, and in some cases prolonged rest has been shown to interfere with patient well-being. In direct contrast to the clinical advice regarding physical activity after TBI, animal models of brain injury consistently indicate that exercise is neuroprotective and promotes recovery. Here, we assessed the effect of low and moderate intensity treadmill exercise on functional outcome and hippocampal neural proliferation after brain injury. Using the controlled cortical impact (CCI) mouse model of TBI, we show that 10 days of moderate intensity treadmill exercise initiated after CCI reduces anxiety-like behavior, improves hippocampus-dependent spatial memory, and promotes hippocampal proliferation and newborn neuronal survival. Pathophysiological measures including lesion volume and axon degeneration were not altered by exercise. Taken together, these data reveal that carefully titrated physical activity may be a safe and effective approach to promoting recovery after brain injury.

The sensory representation of causally controlled objects

Intentional control over external objects is informed by our sensory experience of them. To study how causal relationships are learned and effected, we devised a brain machine interface (BMI) task using wide-field calcium signals. Mice learned to entrain activity patterns in arbitrary pairs of cortical regions to guide a visual cursor to a target location for reward. Brain areas that were normally correlated could be rapidly reconfigured to exert control over the cursor in a sensory-feedback-dependent manner. Higher visual cortex was more engaged when expert but not naive animals controlled the cursor. Individual neurons in higher visual cortex responded more strongly to the cursor when mice controlled it than when they passively viewed it, with the greatest response boosting as the cursor approached the target location. Thus, representations of causally controlled objects are sensitive to intention and proximity to the subject's goal, potentially strengthening sensory feedback to allow more fluent control.

Voluntary wheel running effects on intra-accumbens opioid driven diet preferences in male and female rats

Palatability driven feeding and voluntary physical activity are mediated by and influence similar neural mechanisms, notably through the actions of opioids within the nucleus accumbens. Recent studies suggest that access to a voluntary running wheel results in sex dependent behavioral and physiological adaptations related to opioid mediated palatability-driven feeding. To explore this relationship, male and female Wistar rats were given either access to a voluntary running wheel (RUN group) or no access (SED group) for one week prior to being stereotaxically implanted with bilateral cannulae targeting the nucleus accumbens. Following 7 days of recovery, with RUN or SED conditions continuing the duration of the experiment, all rats were assessed daily (2 h/day) for feeding behavior of concurrently accessible high-carbohydrate and high-fat diet for one week. Following this week, all rats were administered the μ-opioid receptor agonist D-Ala2, NMe-Phe4, Glyol5-enkephalin (DAMGO) (0.0025  μg, 0.025  μg, or 0.25 μg/0.5 μl/side) or the opioid antagonist naloxone (20 μg/0.5 μl/side) into the nucleus accumbens and given concurrent access (2 h) to both diets. All groups expressed a significant baseline preference for the high-carbohydrate diet. DAMGO administration, compared to saline treatment, led to significant increased consumption of the high-carbohydrate diet in all treatment groups. While high-fat diet consumption also increased following DAMGO administration, the influence of DAMGO was much more robust for the preferred high-carbohydrate diet in all groups. Compared to males, females consumed significantly more of both diets at baseline and following DAMGO treatment. Both male and female rats in the RUN condition consumed more high-carbohydrate diet compared to rats in the SED condition. While males exhibited similar increased consumption of both diets regardless of RUN or SED condition, females in the RUN condition displayed a greater sensitivity to DAMGO-driven consumption of the preferred high-carbohydrate, compared to SED females.

Unique controlling mechanisms underlying walking with two handheld poles in contrast to those of conventional walking as revealed by split-belt locomotor adaptation

Pole walking (PW), a form of locomotion in which a person holds a pole in each hand, enhances the involvement of alternating upper-limb movement. While this quadruped-like walking increases postural stability for bipedal conventional walking (CW), in terms of the neural controlling mechanisms underlying the two locomotion forms (PW and CW), the similarities and differences remain unknown. The purpose of this study was to compare the neural control of PW and CW from the perspective of locomotor adaptation to a novel environment on a split-belt treadmill. We measured the anterior component of the ground reaction (braking) force during and after split-belt treadmill walking in 12 healthy subjects. The results demonstrated that (1) PW delayed locomotor adaptation when compared with CW; (2) the degrees of transfer of the acquired movement pattern to CW and PW were not different, regardless of whether the novel movement pattern was learned in CW or PW; and (3) the movement pattern learned in CW was washed out by subsequent execution in PW, whereas the movement pattern learned in PW was not completely washed out by subsequent execution in CW. These results suggest that the neural control mechanisms of PW and CW are not independent, and it is possible that PW could be a locomotor behavior built upon a basic locomotor pattern of CW.

Influence of an Added Perceptual Motor Task on Perceived Exertion: A Test of the Dissociation Effect

This experiment showed that adding a perceptual motor task to an effort session on a cycloergometer for 4 men and 4 women led to an increase in perceived exertion. This effect is opposite to the dissociative effect classically reported in the literature. These contrasting results are analyzed according to the rate of processing imposed by the added task.

Attentional Style in Ratings of Perceived Exertion during Physical Exercise

This study assessed the effects of associative and dissociative psychological strategies of attention on heart rate and self-report ratings of perceived exertion (RPE) during cycling performance. Seven trained cyclists performed a control ride, a dissociation ride, and an association ride on a bicycle ergometer at a work rate corresponding to 75% of their maximal heart rate. For the dissociation ride, subjects watched a videotape unrelated to cycling and responded to a key word each time it occurred on tape. For the association ride, subjects focused attention on heart-rate feedback available throughout the ride. During the control ride, attentional focus was not intentionally manipulated. Analysis indicated that the deliberate application of an attentional strategy did not significantly affect heart rate or RPE scores; however, the dissociation condition yielded somewhat higher RPE scores. From a postexperimental interview, four subjects responded that the association ride was the easier to complete, while three subjects responded the control ride was the easier one, matching a possible trend in the data.

Modulations of the Optical Flow Did Not Induce Locomotor Pattern Fluctuations in Treadmill Walking in Man

We report an analysis of gait during human treadmill walking when visual information from the self-displacement velocity was modulated. Removing or sinusoidally modulating the frequency edge information in the optical flow did not induce significant changes in the walking velocity as analyzed using Fast Fourier Transform or in the spatiotemporal gait parameters. While low-frequency fluctuations in displacement speed increased, there was no significant change in locomotor cycle stability. When a constant frequency edge was provided, i.e., when a backward optical flow was added, stride length decreased as compared to the no-optical-flow condition and instantaneous fluctuations in stride amplitude increased. Temporal gait parameters did not change. These partial effects might be better explained by modifications in trunk balance. In humans, modulation of velocity information on self-motion cannot induce unintentional modulation of walking velocity and did not enhance fluctuations in the locomotor pattern. These results argue against the proprioceptive role of sagittal visual-motion information in control of stability of rhythmic leg movement, at least when other proprioceptive feedback sources are available.

Effects of Various Walking Speeds on Probe Reaction Time during Treadmill Walking

The relative attention demanded by standing and walking at five velocities on a treadmill were examined by the measurement of probe reaction time (probe-RT). Subjects were 13 healthy men, who were from 21 to 42 years of age (M = 28.3 yr., SD = 7.4). The mean RT value was shortest at the velocity of 4 km/hr. and became longer at treadmill walking speeds above and below 4 km/hr. The mean preferred velocity of subjects obtained from 10-m free walking was 4.85 km/hr. (3.1 to 6.2 km/hr.), which is reasonably close to the optimal velocity of 4.0 km/hr. during treadmill walking. Walking at the optimum velocity calls for extremely low demands for attention, and walking at velocities higher or lower than this requires more attention.

A Normative Zone of Rpe Ratings for Use during Graded Exercise Testing

The purposes of this investigation were to identify a zone of normality for ratings of perceived exertion (RPE) and to compare the RPE responses in patients with coronary artery disease to this zone. The zone was generated from RPE estimated during the last minute of each stage of a Bruce treadmill test in 44 normal adult men. RPE were regressed against the corresponding MET level for each exercise stage. The zone was established as the 95% confidence interval (CI) spanning the average RPE vs MET regression line. RPE estimated during the last 1.0 min. of a Bruce or Modified Balke treadmill test administered to adult men ( n = 37) with coronary artery disease were compared to the 95% CI zone. A total of 19 (51%) of the coronary artery disease patients estimated RPE during a progressively incremented treadmill test that were above the zone, indicating a comparatively greater than normal perception of strain for a given metabolic stress. The presently generated zone provides a practical use of RPE in the interpretation of clinical exercise tests.

Perceived Effort Step-up Procedure for Self-Regulating Stationary Cycle Exercise Intensity by Patients with Cardiovascular Disease

This study examined the strategy utilized by patients with cardiovascular disease to regulate exercise intensity using the Rating of Perceived Exertion (RPE) and tested if a step-up procedure would reduce overshoot of target heart rate (HR). Also the study investigated if Prescription Congruence and Intensity Discrimination, components of the Intensity Self-regulation Model, could be validated for these patients. An estimation and production paradigm was used. HR was measured at 2-min. intervals during 6-min. stationary cycle ergometer exercise trials. Data for four experimental trials were compared: (1) a work intensity set by experimenter to achieve a target RPE of 11 (Estimation 11), (2) an intensity set by experimenter to achieve a target RPE of 13 (Estimation 13), (3) an intensity varied by participant every 2 min. to produce a target RPE of 13 (Production 13), and (4) a Step-up Procedure with the intensity varied by participant, first producing a target RPE of 11 during the first 2 min., followed by producing a target RPE of 13 from min. 2 to 6 of exercise (Production 11 + 13). A very small effect size was found for HR between Production 13 and Estimation 13, and a moderate effect size was noted for the increased HR when patients produced a target RPE of 13 as compared to 11. The participants could be divided into 2 groups: 10 patients comprised a Higher group whose HR at 2 min. during Production 13 was greater than HR at 2 min. during Estimation 13, and 6 patients in a Lower group with HR at 2 min. during Production 13 less than or equal to HR during Estimation 13. A large effect size was found at 6 min. for the reductions of the Higher group's HR overshoot and for the Lower group's HR undershoot during Production 13. All participants in the Higher group ( n = 10) had a clinically significant 1ER overshoot of 5 beats · min.−1 at 2 min. during Production 13. Using a Step-up Procedure (Production 11 + 13), a large effect size was found for the reduced number of patients ( n = 3) with an overshoot of 5 beats · min.−1 at 2 min. This supports the ability of participants in cardiac rehabilitation programs to meet the Prescription Congruence and Intensity Discrimination components of the Intensity Self-regulation Model in the RPE 11–13 zone. Evidence was found for overshoot/undershoot of target HR at 2 min., supporting a proposed third component, Production Strategy, of the Intensity Self-regulation Model. The 2-min. Step-up Procedure reduced some patients' tendency to “overshoot” target intensity.

Effect of Pedal Rate and Power Output on Rating of Perceived Exertion during Cycle Ergometry Exercise

This study examined differentiated rating of perceived exertion (RPE), heart rate, and heart-rate variability during light cycle ergometry exercise at two different pedal rates. 30 healthy men (22.6 ± 0.9 yr.) were recruited from a student population and completed a continuous 20-min. cycle ergometry exercise protocol, consisting of a 4-min. warm-up (60 rev./min., 30 Watts), followed by four bouts of 4 min. at different combinations of pedal rate (40 or 80 rev./min.) and power output (40 or 80 Watts). The order of the four combinations was counterbalanced across participants. Heart rate was measured using a polar heart-rate monitor, and parasympathetic balance was assessed through time series analysis of heart-rate variability. Measures were compared using a 2 (pedal rate) × 2 (power output) repeated-measures analysis of variance. RPE was significantly greater ( p < .05) at 80 versus 40 rev./min. at 40 W. For both power outputs heart rate was significantly increased, and the high frequency component of heart-rate variability was significandy reduced at 80 compared with 40 rev./min. These findings indicate the RPE was greater at higher than at lower pedalling rates for a light absolute power output which contrasts with previous findings based on use of higher power output. Also, pedal rate had a significant effect on heart rate and heart-rate variability at constant power output.

The Value of Diagnostic Information to Patients with Chest Pain Suggestive of Coronary Artery Disease

Background. The results of diagnostic tests often have a profound impact on the way patients view their health. Decision analyses and clinical guidelines do not routinely consider this, in part because methods are not well developed for measuring the value of testing to patients. Objectives. To measure the value of stress testing to patients with chest pain suggestive of coronary artery disease (CAD) and to improve methods for measuring the value of diagnostic information. Methods. The authors conducted a prospective cohort study of patients with chest pain who were referred from 44 primary care practices for treadmill testing (N = 320). Current health status, perceived life expectancy, anxiety, uncertainty, and preferences for current health states were measured before and 1 week after testing and receipt of the results. Patients also reported the diagnosis given by their physicians after testing. The authors used paired t tests to assess changes before and after testing. Results. Perceived life expectancy lengthened, anxiety decreased, and uncertainty decreased 1 week after exercise testing, compared to before (P < 0.01). For many patients, sytoms were less bothersome after testing than before. There were few changes in perceptions of current health status, as measured by the SF-36. The authors found evidence of reassurance among patients who reported that CAD had been excluded and no evidence of psychological harm among patients who reported a new CAD diagnosis. Conclusions. Patients experienced measurable psychological benefits from noninvasive diagnostic testing for CAD. Similar measurements should be standard components of diagnostic test evaluation.

Listening to Music during Warming-Up Counteracts the Negative Effects of Ramadan Observance on Short-Term Maximal Performance

Aim

The aim of the present study was to examine whether listening to music during warming-up might influence short-term maximal performance (STMP), cognitive anxiety, self-confidence, and enjoyment during Ramadan, and whether these affects might predict STMP.

Methods

Nine male physical education students (age: 21 ± 1.1 years; height: 1.8 ± 0.04 m; body mass: 83 ± 5 kg) volunteered to participate in the present study. A within-subjects design consisted of four experimental sessions: Two sessions occurred one week before Ramadan and two others took place during Ramadan. They were scheduled at 5 p.m. and were conducted as follows: After a 10-minute warm-up either with or without listening to music, each participant performed a 5-m multiple shuttle run test, after which he was asked to answer items intended to assess his affective state during the experimental task.

Results

Our findings revealed that STMP was lower during Ramadan than before Ramadan in the no-music condition. Additionally, it was found that STMP was higher in the music condition than in the no-music condition during Ramadan, and that STMP measured before Ramadan did not differ from that measured during Ramadan in the music condition. Regarding affects, the findings revealed that enjoyment was lower during Ramadan than before Ramadan in the music condition, and that cognitive anxiety was lower in the music condition than in the no-music condition before Ramadan. Self-confidence was not influenced by the experimental conditions.

Conclusion

This study showed that listening to music during warming-up not only would be beneficial for STMP in Ramadan fasters, but also would counteract the negative effects of Ramadan observance on STMP.

The impact of cell phone use on the intensity and liking of a bout of treadmill exercise

This study used a within-subjects design to assess the effect of three common cellular telephone (cell phone) functions (texting, talking, listening to music) on planned exercise. Forty-four young adults (n = 33 females, 21.8 ± 1.3 years) each participated in four, separate, 30-minute exercise conditions on a treadmill in a random order. During each condition, the treadmill speed display was covered and grade was fixed at zero. However, participants were able to alter treadmill speed as desired. Throughout the texting and talking conditions, research personnel used a pre-determined script to simulate cell phone conversations. During the music condition, participants used their cell phone to listen to music of their choice. Finally, participants completed a control condition with no cell phone access. For each condition, average treadmill speed, heart rate and liking (via visual analog scale) were assessed. Treadmill speed (3.4 ± 1.3 miles∙hour^-1), heart rate (122.3 ± 24.3 beats∙min^-1) and liking (7.5 ± 1.5 cm) in the music condition were significantly (p ≤ 0.014) greater than all other conditions. Treadmill speed in the control condition (3.1 ± 1.2 miles∙hour^-1) was significantly (p = 0.04) greater than both texting and talking (2.8 ± 1.1 miles∙hour^-1 each). Heart rate during the control condition (115.4 ± 22.8 beats∙min^-1) was significantly (p = 0.04) greater than texting (109.9 ± 16.4 beats∙min^-1) but not talking (112.6 ± 16.1 beats∙min^-1). Finally, liking during the talking condition (5.4 ± 2.2 cm) was greater (p = 0.05) than the control (4.3 ± 2.2 cm) but not the texting (5.1 ± 2.2 cm) conditions. In conclusion, using a cell phone for listening to music can increase the intensity (speed and heart rate) and liking of a bout of treadmill exercise. However, other common cell phone uses (texting and talking) can interfere with treadmill exercise and reduce intensity.

Identification of multiple genetic loci in the mouse controlling immobility time in the tail suspension and forced swimming tests

Depression is one of the most famous psychiatric disorders in humans in all over the countries and considered a complex neurobehavioral trait and difficult to identify causal genes. Tail suspension test (TST) and forced swimming test (FST) are widely used for assessing depression-like behavior and antidepressant activity in mice. A variety of antidepressant agents are known to reduce immobility time in both TST and FST. To identify genetic determinants of immobility duration in both tests, we analyzed 101 F2 mice from an intercross between C57BL/6 and DBA/2 strains. Quantitative trait locus (QTL) mapping using 106 microsatellite markers revealed three loci (two significant and one suggestive) and five suggestive loci controlling immobility time in the TST and FST, respectively. Results of QTL analysis suggest a broad description of the genetic architecture underlying depression, providing underpinnings for identifying novel molecular targets for antidepressants to clear the complex genetic mechanisms of depressive disorders.

Maximal heart rate: influence of sport practice during childhood and adolescence

BACKGROUND

The heart rate (HR) achieved at the end of an exercise test (ET) is called maximal HR and is known to have clinical and epidemiological relevance. For its correct measurement, it is necessary that the ET be truly maximal.

OBJECTIVE

To evaluate the influence of a history of intense physical activity and/or participation in sports competitions during youth on the maximal HR (% of age-predicted HR) on a clinical cardiopulmonary exercise test (CPET).

METHODS

A total of 600 non-athlete individuals (65.8% males) with a mean age of 46 ± 13.7 years, under primary prevention of cardiovascular diseases and who underwent maximal CPET, were retrospectively selected. Their physical activity profile during childhood/adolescence (PAPCA) was classified in scores growing from 0 to 4, with value 2 corresponding to their respective age-predicted levels.

RESULTS

None of the 20 individuals with maximal HR values equal to or greater than 200 bpm had been inactive or somewhat active during childhood/adolescence. A significant association was observed between PAPCA scores and maximal HR (% of age-predicted HR) (p = 0.02), with a 7-bpm higher value for PAPCA scores 3-4 (32.9% of the sample) in comparison to PAPCA 0-2.

CONCLUSION

Two hypotheses exist to explain these results in individuals who had been more active during youth: a) persistence of chronic adaptations to training on the cardiac chronotropism, or b) higher ability and/or motivation to achieve a truly maximal CPET. Information on the physical activity profile during childhood / adolescence may contribute to the interpretation of maximal HR on ET.

[Type D personality in chronic lung diseases: prevalence, psychological features]

AIM

To estimate the prevalence and impact of Type D personality on the psychological status and quality of life (QL) of patients with chronic lung diseases.

SUBJECTS AND METHODS

117 patients (105 men and 12 women; mean age 59.6 +/- 0.9 years) with chronic lung diseases were examined. The DS14 questionnaire was used to identify Type D personality. According to the test results, the patients were divided into 2 groups: 1) 39 Type D patients; 2) 78 non-Type D patients. The levels of depression and anxiety and QL were additionally determined using the SF-36 questionnaire. Clinical and laboratory parameters, spirometric data, and 6-minute walk test (6'WT) distance were estimated.

RESULTS

The Type D versus non-Type D patients had higher levels of situational (46.6 +/- 1.7 and 41.2 +/- 1.2 scores; p = 0.01) and personality (47.6 +/- 1.5 and 43.7 +/- 0.9 scores; p = 0.02) anxiety and depression (42.9 +/- 1.6 and 35.9 +/- 0.8 scores; p = 0.00004), as well as lower QL levels in the vitality (42.2 +/- 2.2 and 52.2 +/- 1.9 scores; p = 0.002), emotional function (20.5 +/- 4.0 and 36.8 +/- 4.4 scores; p = 0.02), and mental health (56.2 +/- 1.9 and 63.4 +/- 1.9 scores; p = 0.006) scales. The 6'WT distance was less in the Type D patients (463.3 +/- 17.2 m)than in non-Type D patients (504.1 +/- 8.7 m); p = 0.02.

CONCLUSION

Type D personality is encountered in 33% of patients with chronic lung diseases associated with the higher level of psychological distress in the patients, with the worsening of a mental component of QL, and with the reduction in exercise tolerance.

Short day lengths alter stress and depressive-like responses, and hippocampal morphology in Siberian hamsters

Many psychological disorders comprise a seasonal component. For instance, seasonal affective disorder (SAD) is characterized by depression during autumn and winter. Because hippocampal atrophy may underlie the symptoms of depression and depressive-like behaviors, one goal of this study was to determine whether short days also induce structural changes in the hippocampus using photoperiod responsive rodents--Siberian hamsters. Exposure to short days increases depressive-like responses (increased immobility in the forced swim test) in hamsters. Male hamsters were housed in either short (LD 8:16) or long days (LD 16:8) for 10 weeks and tested in the forced swim test. Brains were removed and processed for Golgi impregnation. HPA axis function may account for photoperiod-related changes in depressive-like responses. Thus, stress reactivity was assessed in another cohort of photoperiod-manipulated animals. Short days reduced soma size and dendritic complexity in the CA1 region. Photoperiod did not induce gross changes in stress reactivity, but an acute stressor disrupted the typical nocturnal peak in cortisol concentrations. These data reveal that immobility induced by exposure to short days is correlated with reduced CA1 cell complexity (and perhaps connectivity). This study is the first to investigate hippocampal changes in the context of short-day induced immobility and may be relevant for understanding psychological disorders with a seasonal component.

There is an "I" in TEAM: narcissism and social loafing

We investigated narcissism as a moderator of social loafing on a physical performance task. High and low narcissistic individuals twice performed a cycling task in same-sex teams of three: once when identifiability was low; and once when identifiability was high. A significant interaction between narcissism and identifiability was revealed, F(1, 40) = 4.09, p < .05, eta2 = .09 for performance. Follow-up tests indicated that high narcissists' performance significantly increased with greater identifiability, whereas low narcissists displayed no such performance differences. Results suggested that this effect was due to an increase in narcissists' on-task effort (ratings of perceived exertion and heart rate) when they knew that their performance was to be identified.

The exercise and affect relationship: evidence for the dual-mode model and a modified opponent process theory

This study examined the relationship between exertion level and affect using the framework of opponent-process theory and the dual-mode model, with the Activation-Deactivation Adjective Checklist and the State Anxiety Inventory among 14 active and 14 sedentary participants doing 20 min of treadmill exercise at speeds of 5% below, 5% above, and at lactate threshold (LT). We found a significant effect of time, condition, Time × Condition, and Time × Group, but no group, Group × Condition, or Time × Group × Condition effects, such that the 5% above LT condition produced a worsening of affect in-task compared with all other conditions whereas, across conditions, participants experienced in-task increases in energy and tension, and in-task decreases in tiredness and calmness relative to baseline. Posttask, participants experienced mood improvement (decreased tension, anxiety, and increased calmness) across conditions, with a 30-min delay in the above LT condition. These results partially support the dual-mode model and a modified opponent-process theory.

Physical inactivity in patients with COPD, a controlled multi-center pilot-study

BACKGROUND

Physical activity (PA) has been reported to be reduced in severe chronic obstructive pulmonary disease (COPD). Studies in moderate COPD are currently scarce. The aim of the present study was to investigate physical activity in daily life in patients with COPD (n=70) and controls (n=30).

METHODS

A multi-center controlled study was conducted. PA was assessed using a multisensor armband device (SenseWear, BodyMedia, Pittsburgh, PA) and is reported as the average number of steps per day, and the time spent in mild and moderate physical activity.

RESULTS

Patients suffered from mild (n=9), moderate (n=28), severe (n=23) and very severe (n=10) COPD. The time spent in activities with mild (80 + or - 69 min vs 160 + or - 89 min, p<0.0001) and moderate intensity (24 + or - 29 min vs 65 + or - 70 min; p<0.0036) was reduced in patients compared to controls. The number of steps reached 87 + or - 34%, 71 + or - 32%, 49 + or - 34% and 29 + or - 20% of control values in GOLD-stages I to IV respectively. The time spent in activities at moderate intensity was 53 + or - 47%, 41 + or - 45%, 31 + or - 47% and 22 + or - 34% of the values obtained in controls respectively with increasing GOLD-stage. These differences reached statistical significance as of GOLD stage II (p<0.05). No differences were observed among centers.

CONCLUSIONS

Physical activity is reduced early in the disease progression (as of GOLD-stage II). Reductions in physical activities at moderate intensity seem to precede the reduction in the amount of physical activities at lower intensity.

Self-Efficacy Correlates With Leg Muscle Pain During Maximal and Submaximal Cycling Exercise

Quadriceps muscle pain is a naturally occurring consequence of moderate- to high-intensity cycle ergometry. The present study involved an examination of self-efficacy for tolerating muscle pain during exercise as a correlate of muscle pain during maximal and submaximal cycle ergometry. Young adult females (n=16) who were healthy and regularly physically active completed a measure of self-efficacy for tolerating moderate to strong pain in the legs and then undertook a maximal incremental exercise test on a cycle ergometer. Within 1 week, participants completed a 30-minute bout of submaximal exercise (80% VO2peak) on a cycle ergometer. Ratings of quadriceps muscle pain intensity were recorded every minute during the maximal incremental exercise test and every 5 minutes during the submaximal exercise session. Self-efficacy for tolerating pain was moderately inversely correlated with ratings of peak muscle pain during the maximal incremental exercise test (r=-.45) and pain ratings averaged across the submaximal session (r=-.49). Our results are consistent with social-cognitive theory and indicate that self-efficacy for tolerating pain is inversely associated with ratings of muscle pain during maximal and submaximal exercise in healthy and regularly active young adult females. Such findings support a possible examination of strategies for manipulating self-efficacy for tolerating pain and thereby reducing muscle pain during exercise.

PERSPECTIVE

Our data provided evidence that self-efficacy for tolerating moderate to strong muscle pain during exercise correlates with muscle pain intensity ratings during bouts of maximal and submaximal exercise. Future research could identify methods of manipulating self-efficacy as a means of decreasing muscle pain during exercise and ultimately enhancing physical activity participation.

Effect of providing information about normal test results on patients' reassurance: randomised controlled trial

OBJECTIVE

To investigate whether providing information about normal findings before a diagnostic test improves patients' reassurance and reduces anxiety about symptoms.

DESIGN

Randomised controlled trial.

SETTING

Outpatient cardiology clinic.

PARTICIPANTS

92 patients with chest pain referred for a diagnostic exercise stress test.

INTERVENTION

Before undergoing testing patients were randomised to receive standard information (n=28; control group), a pamphlet explaining the function of the test and the meaning of normal test results (n=30; pamphlet group), or the pamphlet and a brief discussion about the meaning of normal test results (n=34; discussion group).

MAIN OUTCOME MEASURES

The primary outcome was patients' reported reassurance on a 5 item scale immediately after the test and at one month. Secondary outcomes were the proportion of patients still with chest pain and still taking cardiac drugs at one month.

RESULTS

The mean levels of reassurance after testing and feedback from the doctor were significantly higher in the discussion group (42.0, 95% confidence interval 39.7 to 44.2) than in the pamphlet (39.2, 36.1 to 42.3) and control groups (35.8, 31.6 to 39.9). This difference was maintained at one month. The proportion of patients still reporting chest pain at one month decreased significantly in the discussion group (to 17%) and pamphlet group (to 28%) but not in the control group (to 36%). A trend was for fewer patients in the discussion group to be taking cardiac drugs at one month.

CONCLUSION

Providing patients with information about normal test results before testing can improve rates of reassurance and reduce the likelihood of future reports of chest pain.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN87589121 [controlled-trials.com].

Mechanisms of dyspnoea and its language in patients with asthma

This study hypothesises that regardless of the global score of dyspnoea intensity, different descriptors may be selected by asthmatic patients during short cardiopulmonary exercise test (sCPET) and methacholine (Mch) inhalation. It also examines whether different qualitative dyspnoea sensations can help explain the underlying mechanisms of the symptom. Minute ventilation (V'E), tidal volume (VT) and inspiratory capacity (IC) were measured in 22 stable asthmatic patients, and the sensation of dyspnoea during Mch inhalation and sCPET was quantitatively (Borg scale) and qualitatively (descriptors) assessed. The work rate and oxygen uptake (V'O2) were also measured during sCPET. Airway obstruction and hyperinflation, as measured by IC reduction, were the best correlates for dyspnoea with Mch. During sCPET, changes in WR, V'O2, V'E and VT significantly correlated with Borg score, with V'E being the best predictor of dyspnoea; IC decreased in eight patients. Furthermore, chest tightness (68%) was the highest reported descriptor during Mch inhalation, whereas work/effort (72%) was the highest during sCPET. In conclusion, obstruction/hyperinflation and work rate are highly reliable predictors of Borg rating of dyspnoea during methacholine inhalation and short cardiopulmonary exercise testing, respectively. Regardless of the global score of intensity dyspnoea, different descriptors may be selected by patients during short cardiopulmonary exercise testing and methacholine inhalation. Various qualities of dyspnoea result from different pathophysiological abnormalities.

Differential perceived exertion measured using a new visual analogue scale during pedaling and running

The purpose of this study was to evaluate the differential perceived exertion measured using a new set of Visual Analogue Scales (VAS) during pedaling and running. The subjects were eleven healthy males. They performed an incremental maximal test and then three 4-min stages of exercise, for both pedaling and running. During the tests, VO2, V(CO2), V(E), f, and HR were monitored continuously. Bla and perceptual variables including VAS consisting of four scales (VAS 1-VAS 4) and Borg's RPE were measured at the end of each stage. Although the VO2 (%VO2max)) and HR for both pedaling and running were not significantly different, Bla in pedaling was significantly higher than that in running. A significant interaction (mode, stage) was also obtained. The VAS 1 of pedaling was significantly higher than that of running. A significant interaction in VAS 1 (mode, stage) was obtained. The VAS 2 of pedaling was significantly higher than that of running. The subjects indicated that local pain became stronger than central pain in pedaling, but they were almost equal in running. In both pedaling and running, leg pain became stronger than arm pain (VAS 3). VAS 4 showed that during running, breathing difficulty and heart pain were almost equal in perceived intensity. However, during pedaling, breathing difficulty became greater than heart pain. Thus, a new four-part visual analogue scale was found to be useful for monitoring exercise intensity. In addition, the new VAS gave us more information in relation to the differential perceived exertion reflected in the different physiological responses obtained by different exercise modes.

A challenge to fitness testing in primary schools

We challenge the tradition of fitness testing in schools on the basis of purpose, procedures and outcomes. A number of assumptions about validity of selected tests are raised. The need to be able to track fitness through childhood into adulthood is challenged with limited scientific evidence of longitudinal tracking. Supporters of wide-scale fitness testing of children in schools include researchers whose intention is to promote public health awareness and policy. But a variety of confounding factors can affect field-based testing and lower the confidence in intra and inter group comparisons. Confounders include variability in motivation, familiarisation, external conditions, group dynamics, self-efficacy in testing, and perceived value of testing and likely outcomes. With acknowledged limitations, a more appropriate context for fitness testing for young people who have a strong commitment to physical activity may lie more in a professionally delivered sports-specific setting rather than in large-scale school-based testing. Given the less than desirable participation in activity outside of school and the distressing prevalence of childhood overweight and obesity, it is unlikely that fitness testing experiences will provide children with much needed positive encouragement for lifelong physical activity. Alternative strategies for school-based assessment of the promotion of child health through physical activity are proposed.

Predictors of success and failure in pulmonary rehabilitation

The purpose of the present study was to identify prognostic features of chronic obstructive pulmonary disease (COPD) associated with success or failure in pulmonary rehabilitation. Patients were stratified according to the Medical Research Council (MRC) dyspnoea score. A total of 74 stable COPD patients (mean+/-sd age 68+/-10 yrs), 21 MRC dyspnoea score grade 1/2, 29 grade 3/4 and 24 grade 5, with a mean forced expiratory volume in one second of 1.1+/-0.6 L, attended for rehabilitation. Assessments consisted of the following: quadriceps torque, 6-minute walking distance (6MWD), Brief Assessment Depression Cards and St George's Respiratory Questionnaire (SGRQ). Predictors of drop-out and of response (a change in SGRQ of four points or 6MWD of 54 m) were tested using binary logistic regression. In total, 51 patients completed the study. Of these, 39 (77%) showed a clinically significant benefit in either 6MWD or SGRQ. Baseline variables were poor predictors of response in each case. Significant differences were seen between MRC dyspnoea score groups for change in 6MWD and SGRQ Score. Only grade 1/2 and 3/4 patients improved. Depression was a risk factor for subject drop-out compared with nondepressed patients. Baseline state is a poor predictor of response to rehabilitation, although Medical Research Council dyspnoea score grade 5 patients showed smaller magnitudes of improvement than patients with less severe Medical Research Council dyspnoea score grades. Risk of drop-out is significantly greater in depressed compared with nondepressed patients.

Psychological and physiological effects of 24-style taijiquan

This study was conducted to determine whether 24-style Taijiquan (24TJQ) exhibits measurable psychological and physiological effects. Twenty-two middle-aged female subjects performed 24TJQ and cycle ergometry exercises at the same intensity determined by the same heart rate during 2 exercises. Electroencephalography and Profile of Mood State (POMS) were monitored before and after 2 exercises. The responses to 24TJQ exercise were different from those to cycle ergometry exercise when the heart rate returned to the resting level: (1) alpha increased and theta decreased significantly in the frontal region, while theta decreased significantly in the central and occipital regions; (2) in the POMS test, an improved positive mood was found following 2 exercises, while negative mood was suppressed following 24TJQ exercise; (3) significant correlations were found between the increased alpha in the frontal region, the decreased theta in the central or occipital region and the vigor of the POMS test. These results suggest that 24TJQ exercise induced a resting awakening state and exhibited a relaxing effect on both mind and body.

Comparisons of physiological and perceptual responses in healthy men and women during standardized arm cranking and task-specific pushing–pulling

OBJECTIVE

Peak cardiorespiratory, metabolic, and perceptual responses in healthy men (n=11) and women (n=11) were compared during two different upper body exercise modes: standardized arm cranking and task-specific pushing-pulling.

METHODS

Each subject completed to volitional exhaustion both an incremental arm cranking and a pushing-pulling exercise continuously, in a random order, on two separate days. Physiological responses were monitored using an automated metabolic cart and a heart rate monitor, and the rating of perceived exertion was obtained using a 15-point Borg Scale.

RESULTS

Peak oxygen uptake, oxygen pulse, respiratory exchange ratio, and ventilation rate were higher and total exercise time to exhaustion was lower during arm cranking compared to pushing-pulling (P<0.05). However, heart rate was similar between exercise modes (P>0.05). Men showed greater physiological responses (absolute oxygen uptake, oxygen pulse, and ventilation rate) and longer exercise time to exhaustion than women (P<0.05). Power output during arm cranking was higher (by 79%) than pushing-pulling (P<0.01), with men demonstrating 30% greater values during both exercise modes (P<0.01). The lower power output generated during pushing-pulling resulted in a greater ratio of peak oxygen uptake to power output (by 72%; P<0.05). Interestingly, although power output and oxygen uptake were lower at the maximal workload, perceived exertion was higher (by 5%) during pushing-pulling (P<0.05).

CONCLUSIONS

Based on the physiological differences, pushing-pulling is found to be metabolically less efficient than arm cranking. However, greater ratings of perceived exertion during pushing-pulling implies that the perception of effort can also be influenced by a low intensity task, such as pushing-pulling, if performed for a prolonged period. Occupational health professionals should be aware of the limitations of utilizing physiological and perceptual responses obtained only from standardized ergometric protocols in predicting the workers' performance effectiveness.

Association Between Hemodynamic Profile During Laboratory Stress and Ambulatory Pulse Pressure

Hemodynamic responses underlying blood pressure reactivity to laboratory stress are theoretically linked to cardiovascular pathophysiology. The present study investigated whether a vascular response predicted ambulatory pulse pressure, a known risk factor for cardiovascular disease. A new model of hemodynamic profile, previously developed by the authors, was applied to 24-h ambulatory data from 30 female and 34 male healthy young adults. Of these, 40 were monitored during a naturalistic stressor (university examination). For females, hemodynamic profile significantly predicted nighttime systolic blood pressure, and 24-h, day-, and nighttime diastolic blood pressure, but not ambulatory pulse pressure. A vascular or mixed hemodynamic profile significantly predicted 24-h and daytime ambulatory pulse pressure in males. The findings are consistent with theories of pathogenic mechanisms involving vascular changes and suggest that, for males, a vascular or mixed hemodynamic profile measured during laboratory stress may be a risk marker for cardiovascular disease, by its association with ambulatory pulse pressure.

Psychological distress and exertional angina in men and women undergoing thallium scintigraphy

The relation between psychological factors and angina has mostly been studied in male patients with confirmed CAD and few have evaluated this relation during actual provocation of ischemia. This study evaluated gender differences in the association between psychological distress and angina pain experience in 907 Caucasian patients (479 women, mean age = 60 years) undergoing exercise stress testing with thallium scintigraphy. Data were analyzed separately for patients with and without exercise related ischemia using a series of 2 (low/high distress) x 2 (gender) ANOVAs as well as binary logistic regressions. Among all patients, distress and gender were associated with greater risk and intensity of angina pain during testing (p < 0.05) and more angina following exertion (p < 0.05) or stress (p < 0.05) at home.

CONCLUSION

angina pain was more severe in women and individuals with high levels of distress, regardless of their ischemic status. A generalized hypersensitivity to pain/symptoms may be indicated in these patients.

Exercise self-efficacy, enjoyment, and feeling states among adolescents

Knowledge of cognitions and feelings related to physical activity (PA) can assist in counseling adolescents to prevent the decrease in PA that occurs during this developmental period. This study, which involves a 2 (gender) 2 (race) 3 (developmental stage) design, examines relationships among PA self-efficacy (SE), enjoyment, and feeling states (FS) during PA and compares responses among 168 African American and European American boys and girls during early, middle, and late adolescence. More positive FS during a standardized PA episode on a treadmill predicts higher postactivity SE and greater enjoyment of the task. FS worsens as the session progresses, particularly for adolescents who in early puberty, report feeling significantly worse than those in both middle and late puberty at 16 minutes and 20 minutes. Findings suggest that nurses should assist adolescents to reduce negative feelings during activity to augment PA enjoyment, as well as SE following PA.

A perceptive individual time trial performed by triathletes to estimate the anaerobic threshold. A preliminary study

AIM

The aim of the study was to test the ability to estimate the power output (PO) and heart rate (HR) associated with ''anaerobic threshold'' levels for triathletes by means of a 30-min perceptive individual time trial (PITT30).

METHODS

Thirteen triathletes (8 males and 5 females) performed an incremental exercise test to estimate maximal parameters such as oxygen uptake, power output and heart rate. From this incremental exercise test, the individual anaerobic threshold (IAT) and ventilatory threshold (VT) for all subjects were estimated. Then, the subjects completed a PITT30 at self-selected work intensity on a stationary ergometer equipped with the SRM Training System. Mean values of PO, HR, and pedalling cadence were recorded continuously between the 5th and the 30th min of the test.

RESULTS

Significant correlations were observed between the mean PO recorded during PITT30 and PO measured at IAT (r=0.88; p<0.0001) and at VT (r=0.89; p<0.0001). Furthermore, bias and limits of agreement confirm the degree of association between the 3

METHODS

However, PITT30 over-estimated HR values compared to the values obtained at IAT and VT.

CONCLUSION

It was concluded that, for triathletes, mean PO measured with PITT30 allows a partial valid estimation of PO associated with 2 known methods of ''anaerobic threshold'' determination. The application of PITT30 may offer a useful tool for athletes and coaches to estimate the ''anaerobic threshold'' in order to control accurately the training effects.

[Factors influencing policy of examination of patients with stable angina pectoris]

The study was made to evaluate the rate of application of different diagnostic methods in patients with stable effort angina (SEA) treated in the cardiological department; influence of various factors (social, demographic, risk factors, clinical course of ischemic heart disease, associated diseases, internal picture of the disease) on choice by the attending physician of the diagnostic policy. The trial included 49 patients (44 male and 5 female aged 42-73 years, median 63 years) without contraindications to stress tests and without mental diseases. Choice of diagnostic tests (bicycle exercise only, Holter ECG monitoring only, bicycle exercise + ECG monitoring, none of the two) was made by attending physicians. Information on social, demographic, risk factors, clinical features of IHD and associated diseases was obtained in the course of semistructured interview 2-5 days before the discharge from the hospital. The internal picture of the disease was studied by psychometric testing using "Reaction to the Disease Questionnaire". The results were the following: only bicycle exercise, only Holter ECG monitoring were performed in 15 (30.6%) and 19 (38.8%) patients, respectively (95% confidence interval was 17.2-44.0% and 24.6-52.9%, respectively). None of the tests was made in 15 (30.6%) patients (95% confidence interval was 17.2-44.0%). The choice of the physician was significantly influenced by two factors: obesity and internal picture of the disease. The physicians preferred to avoid bicycle exercise conduction in obese patients and patients with hypernosognosia who consider ischemic heart disease a catastrophe and suffer of vital fear and helplessness.

Physical activity, self-efficacy, and perceived exertion among adolescents

The relationship of self-efficacy, a sense of confidence in personal physical activity (PA) skills, to perceived exertion during activity was explored among 168 African American and European American boys and girls between 9 and 17 years of age. Participants walked/ran on a treadmill at a speed equivalent to 60% of their peak VO2 for 20 minutes and provided ratings of exertion every 4 minutes. Pre-activity self-efficacy predicted perceived exertion for boys only. Girls were lower than boys in pre-activity self-efficacy and subsequently reported greater perceived exertion. For both genders, lower perceived exertion during PA resulted in higher post-activity self-efficacy. Uncomfortable perceptions of exertion during initial efforts to increase PA are likely to discourage future activity. Interventions that can lower perceptions of exertion may enhance self-efficacy and promote a sense of competence in PA skills.

Regulating intensity using perceived exertion during extended exercise periods

The present study was undertaken to examine the validity of using the OMNI scale of perceived exertion to regulate intensity during extended exercise periods. Forty-eight subjects (24 male, 24 female) were recruited and each subject completed a maximal graded exercise test (GXT) and two 20-min submaximal exercises. During the GXT, ratings of perceived exertion (RPE) as well as oxygen uptake (VO(2)) and heart rate (HR) equivalent to 50 and 70% of maximum VO(2) (VO(2max)) were estimated. During each submaximal exercise, subjects were instructed to produce and maintain a workload equivalent to the RPE estimated at 50 or 70% VO(2max), and VO(2) and HR were measured every 5 min throughout the exercise. Of the 48 subjects, 12 (6 male and 6 female) performed both the estimation and production trials on a treadmill (TM/TM), 12 (6 male and 6 female) performed both the estimation and production trials on a cycle ergometer (C/C), 12 (6 male and 6 female) performed the estimation trial on a treadmill and the production trial on a cycle ergometer (TM/C), and 12 (6 male and 6 female) performed the estimation trial on a cycle ergometer and the production trial on a treadmill (C/TM). No differences in VO(2) between the estimation and any 5 min of the production trial were observed at either intensity in TM/TM and C/C. No differences in HR between the estimation and any 5 min of the production trial were also observed at 50% VO(2max) in TM/TM and at both 50 and 70% VO(2max) in C/C. However, HR was higher at 20th min of the production trial at 70% VO(2max) in TM/TM. Both the VO(2) and HR were generally lower in TM/C and higher in C/TM. However, these differences diminished when values were normalized using VO(2max) of the same mode that other groups had attained. These data suggest that under both intra- and intermodal conditions, using the OMNI perceived exertion scale is effective not only in establishing the target intensity at the onset of exercise, but also in maintaining the intensity throughout a 20-min exercise session.

Hypothalamic-pituitary-adrenal axis reactivity in chronic fatigue syndrome and health under psychological, physiological, and pharmacological stimulation

OBJECTIVES

Subtle alterations of the hypothalamic-pituitary-adrenal (HPA) axis in chronic fatigue syndrome (CFS) have been proposed as a shared pathway linking numerous etiological and perpetuating processes with symptoms and observed physiological abnormalities. Because the HPA axis is involved in the adaptive responses to stress and CFS patients experience a worsening of symptoms after physical and psychological stress, we tested HPA axis functioning with three centrally acting stress tests.

METHODS

We used two procedures mimicking real-life stressors and compared them with a standardized pharmacological neuroendocrine challenge test. CFS patients were compared with healthy control subjects regarding their cardiovascular and endocrine reactivity in a psychosocial stress test and a standardized exercise test, and their endocrine response in the insulin tolerance test (ITT).

RESULTS

Controlling for possible confounding variables, we found significantly lower ACTH response levels in the psychosocial stress test and the exercise test, and significantly lower ACTH responses in the ITT, with no differences in plasma total cortisol responses. Also, salivary-free cortisol responses did not differ between the groups in the psychosocial stress test and the exercise test but were significantly higher for the CFS patients in the ITT. In all tests CFS patients had significantly reduced baseline ACTH levels.

CONCLUSIONS

These results suggest that CFS patients are capable of mounting a sufficient cortisol response under different types of stress but that on a central level subtle dysregulations of the HPA axis exist.

Isokinetic knee joint test in "gonalgia sine materia"

Fifty-four subjects, aged between 20 and 35 years, divided into two subgroups, respectively 30 healthy subjects (17 males and 13 females) and 24 subjects with "gonalgia sine materia" (13 males and 11 females) underwent isokinetic exercise test in order to compare their dominant limb with the not dominant one as regard as the strength of extensor and flexor muscles of the knee. No statistically significant difference was found in any of the studied parameters in the comparison between the dominant limb and the not dominant one, both within the subgroup of healthy subjects and within the subgroup of subjects with "gonalgia sine materia". Authors conclude that psychological features may play a preeminent role in the genesis, as well as in the maintenance of "gonalgia sine materia", thus confirming previous data available in medical literature.

Identification of multiple genetic loci linked to the propensity for "behavioral despair" in mice

The forced swim test (FST) and tail suspension test (TST) are widely used and well established screening paradigms for antidepressants. A variety of antidepressive agents are known to reduce immobility time in both FST and TST. To identify genetic determinants of immobility duration in both tests, we analyzed 560 F2 mice from an intercross between C57BL/6 (B6) and C3H/He (C3) strains. Composite interval mapping revealed five major loci (suggestive and significant linkage) affecting immobility in the FST, and four loci for the TST. The quantitative trait loci (QTL) on chromosomes 8 and 11 overlap between the two behavioral measures. Genome-wide interaction analysis, which was developed to identify locus pairs that may contribute epistatically to a phenotype, detected two pairs of chromosomal loci for the TST. The QTL on chromosome 11 and its associated epistatic TST-QTL on chromosome X encode gamma-aminobutyric acid type A (GABA(A)) receptor subunits as candidates. Sequence and expression analyses of these genes from the two parental strains revealed a significantly lower expression of the alpha1 subunit gene in the frontal cortex of B6 mice compared to C3 mice. The present quantitative trait study should open up avenues for identifying novel molecular targets for antidepressants and unraveling the complex genetic mechanisms of depressive and anxiety disorders.

Perceived Exertion During Incremental Cycling is not Influenced by the Type A Behavior Pattern

Recent publications have perpetuated a concern that the Type A Behavior Pattern (TABP) influences ratings of perceived exertion (RPE) during exercise testing. Previous studies of this topic used the Jenkins Activity Survey (JAS) which lacks validity for predicting the criterion Structured Interview (SI) for TABP and used exercise protocols that were unstandardized or yielded results that were uninterpretable for clinical exercise prescription. We used the SI to classify 44 normotensive men (18-35 y) according to TABP and compared their RPE during an incremental cycling test to peak oxygen uptake (VO2peak). Groups did not differ on maximal test performance or RPE at any stage of the test, even after adjusting RPE for small group variations in % VO2peak and ventilatory equivalent for oxygen, which are strong correlates of RPE during incremental exercise. The findings agree with our prior report [14] that no relationship existed between RPE and several self-report measures of TABP. We conclude that there is no empirical basis for the view that the Type A Behavior Pattern affects cycling performance or ratings of perceived exertion during standard exercise testing in young white men.

Effects of fluid ingestion on cognitive function after heat stress or exercise-induced dehydration

This study investigated the effects of heat exposure, exercise-induced dehydration and fluid ingestion on cognitive performance. Seven healthy men, unacclimatized to heat, were kept euhydrated or were dehydrated by controlled passive exposure to heat (H, two sessions) or by treadmill exercise (E, two sessions) up to a weight loss of 2.8%. On completion of a 1-h recovery period, the subjects drank a solution containing 50 g l(-1) glucose and 1.34 g l(-1) NaCl in a volume of water corresponding to 100% of his body weight loss induced by dehydration. (H1 and E1) or levels of fluid deficit were maintained (H0, E0). In the E0, H0 and control conditions, the subject drank a solution containing the same quantity of glucose diluted in 100 ml of water. Psychological tests were administered 30 min after the dehydration phase and 2 h after fluid ingestion. Both dehydration conditions impaired cognitive abilities (i.e. perceptive discrimination, short-term memory), as well as subjective estimates of fatigue, without any relevant differences between the methods. By 3.5 h after fluid deficit, dehydration (H0 and E0) no longer had any adverse effect, although the subjects felt increasingly tired. Thus, there was no beneficial effect of fluid ingestion (H1 and E1) on the cognitive variables. However, long-term memory retrieval was impaired in both control and dehydration situations, whereas there was no decrement in performance in the fluid ingestion condition (H1, E1).

Anticipatory blood pressure responses to exercise are associated with left ventricular mass in Finnish men: Kuopio Ischemic Heart Disease Risk Factor Study

BACKGROUND

Exaggerated cardiovascular reactivity to psychological demands may contribute to the development of left ventricular (LV) hypertrophy. We examined the cross-sectional association between anticipatory blood pressure (BP) responses to bicycle exercise and LV mass in the Kuopio Ischemic Heart Disease Risk Factor Study, a population-based epidemiological sample.

METHODS AND RESULTS

Among 876 men from 4 age cohorts (ages 42, 48, 58, and 64 years), we collected echocardiographic assessments of LV mass along with measures of BP response taken before bicycle ergometry testing. Anticipatory BP responses were positively associated with LV mass, with significant associations only among younger (age <50 years) subjects with elevated resting pressures (3-way interactions for anticipatory BP x age x resting pressure for systolic and diastolic BP, all P:<0.05; for younger subjects with elevated systolic BP, P:<0. 01; and for younger subjects with elevated diastolic BP, P:<0.001). Among these subgroups, exaggerated anticipatory BP responses (top quartile) were associated with an incremental increase in LV mass of 10% or greater, corrected for body surface area. Results remained significant after adjusting for age, education, salt consumption, and resting BP, and the pattern of findings was maintained among men with no previous history of cardiovascular disease.

CONCLUSIONS

The tendency to show exaggerated pressor responses to psychological demands may be a significant independent correlate of LV mass, especially among young men with high resting pressures. This is the first study to examine such associations in a middle-aged population sample.

[The communication process in the care of patients during echocardiography]

The article reviews some aspects of the communication process, its basic concepts, how it is approached in the theories of the nurses, and proposes to make reflections on the communication in the context of the patient undergoing the stress-echo study. Our goal is to emphasize and to rescue some important aspects related to the communication in health allies area, which is practiced in a constant manner in the daily practices of the nurse. Finally, this paper wishes to emphasize the importance of the knowledge of this process, incorporating it to the practice.

Recovery from stress in two different postures and in Shavasana--a yogic relaxation posture

The recovery from induced physiological stress in Shavasana (a yogic relaxation posture) and two other postures (resting in chair and resting supine posture) was compared. Twenty one males and 6 females (age 21-30 yrs) were allowed to take rest in one of the above postures immediately after completing the scheduled treadmill running. The recovery was assessed in terms of Heart Rate (HR) and Blood pressure (BP). HR and BP were measured before and every two minutes after the treadmill running till they returned to the initial level. The results revealed that the effects of stress was reversed in significantly (P < 0.01) shorter time in Shavasana, compared to the resting posture in chair and a supine posture.

The Psychophysiological Investigations of Myocardial Ischemia (PIMI) study: objective, methods, and variability of measures

OBJECTIVE

This study evaluated physiological, neuroendocrine, and psychological status and functioning of patients with coronary artery disease in order to clarify their role in the expression of symptoms during myocardial ischemia (MI), and to establish repeatability of responses to mental stress. Design and methods of the study are presented.

METHODS

One hundred ninety-six coronary artery disease patients were examined during physical and mental stress tests in four hospitals. Eligibility criteria included narrowing of at least 50% in the diameter of at least one major coronary artery or verified history of myocardial infarction, and evidence of ischemia on an exercise treadmill test. Psychological, biochemical, and autonomic function data were obtained before, during, and after exposure to mental and exercise stressors during 2 or 3 half-days of testing. Ventricular function was assessed by radionuclide ventriculography, and daily ischemia by ambulatory electrocardiography. Sixty patients returned for a short-term mental stress repeatability study. Twenty-nine individuals presumed to be free of coronary disease were also examined to establish reference values for cardiac responses to mental stress.

RESULTS

Study participants were 41 to 80 years of age; 83 (42%) had a history of MI, 6 (3%) of congestive heart failure, and 163 (83%) of chest pain; 170 (87%) were men; and 90 (46%) had ischemia accompanied by angina during exercise treadmill testing. Ischemia during ambulatory monitoring was found in 35 of 90 (39%) patients with and 48 of 106 (45%) patients without angina during exercise-provoked ischemia. Intraobserver variability of ejection fraction changes during bicycle exercise and two mental stress tests (Speech and Stroop) was good (kappa = 1.0, .90, and .76, respectively; percent agreement = 100, 97.5, and 93.8%, respectively). Variability of assessed wall motion abnormalities during bicycle exercise was better (kappa, agreement = 85%) than during Speech or Stroop kappa and .57, percent agreement = 70% and 82.5%, respectively).

CONCLUSIONS

Study design, quality control data, and baseline characteristics of patients enrolled for a clinical study of symptomatic and asymptomatic myocardial ischemia are described. Lower repeatability of reading wall motion abnormalities during mental stress than during exercise may be due to smaller effects on wall motion and lack of an indicator for peak mental stress.

Reproducibility of mental stress-induced myocardial ischemia in the Psychophysiological Investigations of Myocardial Ischemia (PIMI)

OBJECTIVE

Many patients with coronary artery disease (CAD) develop myocardial ischemia in response to mental stress. This has been documented both in the natural environment and in the laboratory. However, the reproducibility of laboratory mental stress-induced ischemia has not been investigated.

METHOD

Sixty patients with documented CAD and a positive exercise stress test discontinued cardiac medications and underwent two standardized mental stress tests (a timed Stroop Color-Word test and a public speaking task) in a nuclear cardiology laboratory (Visit 1), and repeated this procedure between 2 and 8 weeks later (Visit 2). Measurements of cardiovascular function and neurohormonal responses were obtained throughout testing, and mood state was assessed before and after testing.

RESULTS

Sixty-eight percent of the 56 patients with detailed radionuclide data from both visits had consistent responses (ie, ischemia either present during both sessions or absent during both) to the Stroop task (kappa = .29, p = .03), 61% had consistent responses to the speech task (kappa = .20, p = .12), and 60% had consistent responses when ischemia was considered present if it occurred during either the Stroop test, the speech task, or both, and absent if it did not occur during either task (kappa = .22, p = .07). Hemodynamic and neuroendocrine responses to the tests were moderately reproducible.

CONCLUSIONS

We conclude that two popular laboratory tests for mental stress-induced myocardial ischemia are modestly reproducible. The relatively low reproducibility is probably influenced by uncertainties in detecting relatively small changes in wall motion, habituation of the patient to repeated exposure to psychological stressors, and physiological differences in threshold for ischemia on different days of testing.

The relationship of alexithymia to subjective and biomedical measures of disease

Although alexithymia is found in patients with various somatic disorders, it is unclear whether alexithymia is related to organic disease, or just to illness behavior. In 2 studies of patients, the authors related alexithymia (using the Toronto Alexithymia Scale-20 for assessment) to both subjective reports and biomedical measures of disease. In Study I, alexithymia was correlated with symptoms, but not CD4 counts, among adults who had tested positive for the human immunodeficiency virus. In Study 2, alexithymia was associated with the presence or absence of chest pain during exercise testing, but not with ischemic heart disease. These studies suggest that alexithymia, especially difficulty identifying and/or describing feelings, is related to increased illness behavior, but alexithymia may not be related to the presence or severity of organic disease.

Validity of rating of perceived exertion during graded exercise testing in apparently healthy adults and cardiac patients

PURPOSE

Recent exercise guidelines recommend a generalized rating of perceived exertion (RPE) range of 12 to 16 (15-point Borg scale) as the perceptual range associated with a physiological training effect. However, whether an individual who selects an RPE within the generalized range during an graded exercise test or exercise training, is actually within the correlated physiological range (50 to 85% maximum oxygen consumption [VO2max]) has not been studied in large samples of apparently healthy individuals or cardiac patients. The purpose of the present study was to assess the validity of the generalized RPE recommendations in a large heterogeneous group of apparently healthy subjects and cardiac patients.

METHODS

Subjects included apparently healthy adults (N = 463) and cardiac patients (N = 217) who presented for a sign-symptom limited maximal graded exercise test (SSLMGXT). Ratings of perceived exertion associated with relative exercise intensities of 60 and 80% of maximal heart rate reserve (MHRR) and peak exercise were selected for analyses.

RESULTS

Significant interindividual variability in RPE was observed at both relative exercise intensities (6 to 20 RPE range at 60% MHRR; 8 to 20 RPE range at 80% MHRR) for both populations. Thirty-nine percent of healthy subjects and 32% of cardiac patients reported an RPE outside an 11 to 14 range at 60% of MHRR, whereas 32% of healthy subjects and 52% of cardiac patients reported an RPE outside of a 14 to 17 range at 80% of MHRR. Peak RPE was higher for the apparently healthy subjects compared with the cardiac patients (18.8 +/- 1.2 versus 16.5 +/- 1.8; P < 0.01).

CONCLUSIONS

These results challenge the applicability of the generalized RPE recommendations described in recent exercise guidelines under typical clinical exercise testing conditions. The basis for the generalized RPE recommendations warrant further investigation. Those who desire to use RPE as a marker of relative exercise intensity during SSLMGXT should take into consideration the large interindividual variability in these measures.