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55 children with bronchial asthma were tested using three exercise provocation tests: a treadmill, stairways running and cycloergometer. The results were evaluated on the base of the lung function tests, auscultation and airways resistance measurement with occlusion method. Of these three tests the treadmill test seemed to be the most useful to prove bronchial hyperreactivity towards exercise. Stairways running occurred to be very congenial. The study also proved usefulness of auscultation in evaluating of bronchial constriction after exercise.
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CONTEXT: Exertion has been reported to acutely increase the risk of sudden coronary death, but the underlying mechanisms are unclear. OBJECTIVE: To determine the frequency of plaque rupture in sudden deaths related to exertion compared with sudden deaths not related to exertion. DESIGN: Autopsy survey. Coronary arteries were perfusion fixed and segments with more than 50% luminal narrowing were examined histologically. Ruptured plaques were defined as intraplaque hemorrhage with disruption of the fibrous cap and luminal thrombus. Exertion before death was determined by the investigator of the death. SETTING: Medical examiner's office. PATIENTS: A total of 141 men with severe coronary artery disease who died suddenly, including 116 whose deaths occurred at rest (mean [SD] age, 51 [11] years) and 25 who died during strenuous activity or emotional stress (age, 49 [9] years). MAIN OUTCOME MEASURES: The frequency and morphology of plaque rupture was compared in men dying at rest vs those dying during exertion. Independent association of risk factors (total cholesterol, high-density lipoprotein cholesterol, glycosylated hemoglobin, cigarette smoking) in addition to acute exertion with plaque rupture were determined. RESULTS: The mean (SD) number of vulnerable plaques in the coronary arteries of men in the exertional-death group was 1.6 (1.5) and in the at-rest group was 0.9 (1.2) (P=.03). The culprit plaque in men dying during exertion was plaque rupture in 17 (68%) of 25 vs 27 (23%) of 116 men dying at rest (P<.001). Hemorrhage into the plaque occurred in 18 (72%) of 25 men in the exertional-death group and 47 (41%) of 116 men in the rest group (P=.007). Histological evidence of acute myocardial infarction was present in 0 of 25 in the exertion group and in 15 (13%) of 116 in the rest group. Men dying during exertion had a significantly higher mean (SD) total cholesterol-high-density lipoprotein cholesterol ratio (8.2 [3.0]) than those dying at rest (6.2 [ 2.7]; P=.002), and the majority (21/25) were not conditioned. In multivariate analysis, both exertion (P=.002) and total cholesterol-high-density lipoprotein cholesterol ratio (P=.002) were associated with acute plaque rupture, independent of age and other cardiac risk factors. CONCLUSION: In men with severe coronary artery disease, sudden death related to exertion was associated with acute plaque rupture.
The International Headache Society applies the term exertional headache to head pain precipitated by exertion. The Society recognizes cough headache and sexual headache as distinct diagnoses. All three types of headache share characteristics and mechanisms, and together may be considered as headache provoked by exertional factors ( Table 1). In distinction to more typical headaches, such as tension-type headaches or migraine, HAPEF is brief, lasting seconds to minutes, and begins immediately following the precipitating exertion. Headache provoked by exertional factors may occur by itself, or in association with headaches that are not exertional. Secondary (or symptomatic) HAPEF arises as a result of an underlying disorder; primary (or benign) HAPEF has no underlying cause. Clinicians must consider HAPEF potentially serious until appropriate investigations are undertaken. Fortunately, disorders that underlie secondary headaches usually become apparent with examination or laboratory testing. Clinical features of the headaches may also offer a clue (Table 2). Several theories have been put forth to explain the underlying mechanism of exertional, cough, and sexual headache. The leading explanation regarding all three involves exertional factors leading to a sudden increase in intracranial pressure or an inappropriate reaction in the cerebral vasculature. Because exertion may also be a migraine trigger, neural hypersensitivity, similar to migraine, may also play a role in HAPEF. The literature contains only several small case studies that deal with treatment of exertional headache, and just one double blind, placebo-controlled study. The consensus to date is that secondary HAPEF resolves if the underlying illness can be treated; primary HAPEF responds well to prophylactic treatment. Treatment strategy varies little among headaches precipitated by cough, sex, or other forms of exertion. Avoidance strategies, sometimes combined with medication (particularly indomethacin), can effectively treat headaches produced by exertional factors in most cases.
OBJECTIVE: To explore in detail the duration of exertional headache attacks and explicitly to identify cases of prolonged exertional headache. BACKGROUND: The prevalence of exertional headache in general population samples may exceed 10%. The prevalence and distinguishing clinical characteristics of prolonged exertional headache are not well delineated. METHODS: One author (O.S.) personally interviewed 1838 parishioners (88.6%) of ages 18 to 65 years living in a southern Norwegian commune. Questions relevant to exertional headache were included. RESULTS: As recently reported elsewhere, exertional headache was present in 12.3% of those questioned. With 1 hour set as a tentative border for short- versus long-duration exertional headache, there were approximately equal numbers with short- and long-lasting attacks; prevalence of short-lasting attacks was 6.3% and long-lasting attack prevalence was 6.0%. In regards to other epidemiologic and clinical features, the long-lasting cases did not seem to deviate from the short-lasting cases; both categories had a moderate female preponderance and similar age of onset. There was a somewhat higher mean number of "migrainelike features" in the long-lasting than in the short-lasting variety of exertional headache. Exertional headache attacks could last up to 24 hours. CONCLUSIONS; There seems to be little reason to subdivide exertional headache into 2 separate varieties according to attack duration. Exertional headache attacks have "migrainelike" features but do not seem to be "form fruste" migraine attacks. The long-lasting variety is not uncommon.
BACKGROUND: 1) To examine the validity and accuracy of the CR-10 scale for evaluating perceived exertion, and 2) to assess gender differences in perceived exertion across different levels of contraction intensity. METHODS EXPERIMENTAL DESIGN: cross-sectional, comparative design. SETTING: Human Performance and Fatigue Laboratory, Eastern Washington University. SUBJECTS: 30 healthy, college age volunteers (15 males, 15 females). MEASURES: All subjects were assessed for isometric torque and perceived exertion of the quadriceps femoris muscles, via the CR-10 scale. One low anchor was applied under resting conditions with the knee flexed to 60 degrees, and a high anchor was applied during a maximal voluntary muscle contraction (MVC). SUBJECTS performed five-second isometric contractions equivalent to 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, and 90% of their MVC, in a random order, and were assessed for perceived exertion by visually observing the CR-10 scale. One sample "t"-tests and 95% confidence intervals were calculated for perceived exertion at each relative torque level. A single factor ANOVA with repeated measures was performed across al levels of exercise intensity. Linearity for perceived exertion was assessed via regression analysis. RESULTS: Perceived exertion at each exercise intensity were as follows: 10%: 1.87+/-1.14, 20%: 2.43+/-1.19, 30%: 3.5+/-1.36, 40%: 3.97+/-1.52, 50%: 4.73+/-1.28, 60%: 5.53+/-1.28, 70%: 6.73+/-1.62, 80%: 7.57+/-1.72, and 90%: 8.6+/-1.52. The increase in perceived exertion across the intensity spectrum was found to fit both linear and quadratic trends. There were no gender differences in perceived exertion across all levels of exercise intensity. CONCLUSIONS: The findings demonstrate that the CR-10 scale closely approximates perceived exertion of the quadriceps femoris muscles during sub-maximal, static contractions, and is not gender specific.
Photographs were taken of subjects exerting in specified directions with one hand on the handle of a triaxial force measurement system. The applied forces were recorded and posture analysis was undertaken to investigate relationships between three-dimensional force exertion and posture. The postural stability diagram, which in previous studies has been applied to fore-and-aft exertions, was applied to the vertical plane containing the manual force vector and to the horizontal plane. The vertical plane analysis provided an insight into postures associated with weak and strong exertion. The horizontal plane analysis emphasized the importance of developing torque as well as thrust at the foot base in order to exert laterally directed forces. Exertions involving a right or left component were associated with a horizontal moment at the feet of the order of 50 Nm. This moment is an important factor in the demands made upon the body during asymmetrical exertion, and the mechanisms for achieving it deserve further investigation. RELEVANCE: Exertion is not normally restricted to the sagittal plane. The approach adopted in this paper gives an insight into how body deployment relates to the direction and magnitude of exertion. Biomechanical models of asymmetric exertion should reflect the principles that have emerged.
BACKGROUND: To our knowledge, no data have been reported on the effects of exercise training (EXT) on central respiratory motor output or neuromuscular coupling (NMC) of the ventilatory pump, and their potential association with exertional dyspnea. Accurate assessment of these important clinical outcomes is integral to effective management of breathlessness of patients with COPD. MATERIAL AND METHODS: Twenty consecutive patients with stable moderate-to-severe COPD were tested at 6-week intervals at baseline, after a nonintervention control period (pre-EXT), and after EXT. Patients entered an outpatient pulmonary rehabilitation program involving regular exercise on a bicycle. Incremental symptom-limited exercise testing (1-min increments of 10 W) was performed on an electronically braked cycle ergometer. Oxygen uptake (O(2)), carbon dioxide output (CO(2)), minute ventilation (E), time, and volume components of the respiratory cycle and, in six patients, esophageal pressure swings (Pessw), both as actual values and as percentage of maximal (most negative in sign) esophageal pressure during sniff maneuver (Pessn), were measured continuously over the runs. Exertional dyspnea and leg effort were evaluated by administering a Borg scale. RESULTS: Measurements at baseline and pre-EXT were similar. Significant increase in exercise capacity was found in response to EXT: (1) peak work rate (WR), O(2), CO(2), E, tidal volume (VT), and heart rate increased, while peak exertional dyspnea and leg effort did not significantly change; (2) exertional dyspnea/O(2) and exertional dyspnea/CO(2) decreased while E/O(2) and E/CO(2) remained unchanged. The slope of both exertional dyspnea and leg effort relative to E fell significantly after EXT; (3) at standardized WR, E, and CO(2), exertional dyspnea and leg effort decreased while inspiratory capacity (IC) increased. Decrease in E was accomplished primarily by decrease in respiratory rate (RR) and increase in both inspiratory time (TI) and expiratory time; VT slightly increased, while inspiratory drive (VT/TI) and duty cycle (TI/total time of the respiratory cycle) remained unchanged. The decrease in Pessw and the increase in VT were associated with lower exertional dyspnea after EXT; (4) at standardized E, VT, RR, and IC, Pessw and Pessw(%Pessn)/VT remained unchanged while exertional dyspnea and leg effort decreased with EXT. CONCLUSION: In conclusion, increases in NMC, aerobic capacity, and tolerance to dyspnogenic stimuli and possibly breathing retraining are likely to contribute to the relief of both exertional dyspnea and leg effort after EXT.
BACKGROUND: The study examined the role of relaxation and aggressive types of imagery and the effect of goal orientations, self efficacy, self control, and determination on exertion tolerance. METHODS EXPERIMENTAL DESIGN: the participants underwent an exertive task in which they were required to squeeze a dynamometer, at 50% of their maximal hand-grip capacity, for as long as they could. Perceived exertion was measured every 15 sec during the task. The time that elapsed between rating exertion as "strong", and dropping the handbar under 10% of the designated 50% criterion, was considered as the "zone of exertion tolerance". PARTICIPANTS: forty-eight female university students were randomly assigned into 3 groups. INTERVENTIONS: two imagery techniques, one under relaxing and one under aggressive conditions were taught and then applied. In the control condition, discussions were conducted. MEASURES: traits such as goal orientation (task and ego), physical self-efficacy and self-control were measured prior to performing the task, while rate of perceived exertion task-specific determination (i.e., task-related confidence, commitment, exertion tolerance, and effort investment) were measured before, during and after the task. RESULTS: The results showed an average of 31% and 28% increase in exertion tolerance in participants who used aggressive and relaxation imagery techniques respectively, compared to 4% reduction in the controls. RM ANOVA indicated equality between the two imagery groups but both were significantly different from the control group. Physical self-efficacy, self-control, and task-specific determination were found nonsignificant, but their important roles in coping with aversive stimuli are highlighted. It was evident that the "coping" mechanism rather than the "distraction" mechanism accounted for the larger sustain in the "zone of exertion tolerance". CONCLUSIONS: Imagery can be used efficiently in exertion tolerance but more studies are needed on athletes.
CONTEXT: Vigorous physical exertion transiently increases the risk of acute myocardial infarction (MI), but little is known about the clinical characteristics of exertion-related MI. OBJECTIVE: To compare the clinical and angiographic characteristics of patients who had an exertion-related acute MI vs those who experienced an MI not related to exertion. DESIGN AND SETTING: Prospective observational cohort study of patients with an acute MI referred to a tertiary care hospital for primary angioplasty. PATIENTS: Of 1048 patients with acute MI, 640 (64 who experienced an exertion-related MI and 576 who did not) were selected for treatment with primary angioplasty and admitted between August 1995 and November 1998. MAIN OUTCOME MEASURES: Clinical characteristics of the patients, including their habitual physical activity (determined by the Framingham Physical Activity Index and the Lipid Research Clinic Physical Activity Questionnaire), angiographic findings during coronary angiography, and the relative risk (RR) of MI during exertion. RESULTS: Patients who experienced exertion-related MI were more frequently men (86% vs 68%), hyperlipidemic (62% vs 40%), and smokers (59% vs 37%), were more likely to present with ventricular fibrillation (20% vs 11%), Killip classification III or IV heart failure (44% vs 22%), single-vessel disease (50% vs 28%), and a large thrombus in the infarct artery (64% vs 35%) and were more likely to be classified as having very low or low activity (84% vs 66%). The RR of experiencing an MI during exertion was 10.1 times greater than the risk at other times (95% confidence interval [CI], 1.6-65.6), with the highest risk among patients classified as very low active (RR, 30.5; 95% CI, 4.4-209.9) and low active (RR, 20.9; 95% CI, 3.1-142.1). CONCLUSION: These results show that exertion-related MIs occur in habitually inactive people with multiple cardiac risk factors. These individuals may benefit from modest exercise training and aggressive risk-factor modification before they perform vigorous physical activity.
BACKGROUND: Retrospective and cross-sectional data suggest that vigorous exertion can trigger cardiac arrest or sudden death and that habitual exercise may diminish this risk. However, the role of physical activity in precipitating or preventing sudden death has not been assessed prospectively in a large number of subjects. METHODS: We used a prospective, nested case-crossover design within the Physicians' Health Study to compare the risk of sudden death during and up to 30 minutes after an episode of vigorous exertion with that during periods of lighter exertion or none. We then evaluated whether habitual vigorous exercise modified the risk of sudden death that was associated with vigorous exertion. In addition, the relation of vigorous exercise to the overall risk of sudden death and nonsudden death from coronary heart disease was assessed. RESULTS: During 12 years of follow-up, 122 sudden deaths were confirmed among the 21,481 male physicians who were initially free of self-reported cardiovascular disease and who provided information on their habitual level of exercise at base line. The relative risk of-sudden death during and up to 30 minutes after vigorous exertion was 16.9 (95 percent confidence interval, 10.5 to 27.0; P<0.001). However, the absolute risk of sudden death during any particular episode of vigorous exertion was extremely low (1 sudden death per 1.51 million episodes of exertion). Habitual vigorous exercise attenuated the relative risk of sudden death that was associated with an episode of vigorous exertion (P value for trend=0.006). The base-line level of exercise was not associated with the overall risk of subsequent sudden death. CONCLUSIONS: These prospective data from a study of U.S. male physicians suggest that habitual vigorous exercise diminishes the risk of sudden death during vigorous exertion.