Strenuous Physical Exertion Research Articles

Interactions between the environment, physical demands, and social engagement at an Aphasia Camp

Individuals with aphasia experience impairments in communication that can be exacerbated by environmental and task demands. This investigation examined the interaction between physical-demands, social-engagement, and environment. An interdisciplinary team, including speech language pathologists and a kinesiologist measured the activities of individuals with aphasia at the Chippewa Valley Aphasia Camp. Accelerometers were used to measure degree of physical exertion as an indication of physical demands. The Clinical Discourse Assessment (Damico, 1991), Measure of Participation in Conversation and Measure of Skill in Supported Conversation (Kagan et al., 2004), qualitative analyses, and investigator field notes served as indicators of social engagement. The International Classification of Disease Functioning (ICF) was used to code environmental factors, which either served as a facilitator or barrier to participation. Qualitative analyses indicate that the presence of physical environmental barriers and more strenuous physical exertion sometimes serve to decrease social engagement and exchange. However, partners who served as facilitators enabled participants to overcome high environmental and/or physical task demands to support successful social engagement and exchange. These analyses suggest that participants with aphasia can overcome physical environmental barriers and/or high physical task demands, given effective partner supports. This investigation contributes to a small body of research regarding the interaction between environmental demands and social communication among individuals with aphasia. Further, the investigation contributes empirical information about the environment and social communication context of a rustic Aphasia Camp.

The Effects of Social Support on Strenuous Physical Exercise

In humans, socio-environmental cues play an important role in determining adaptive psychophysiological states and behaviours. In sport and exercise, cues to cohesive groups and close, supportive relationships are ubiquitous, possibly because of their effects on neurobiological mechanisms underlying physical performance. Clinical research has shown that the presence of supportive others can lead to reductions in perceptions of pain, while research from sport and exercise science has shown that pain and physical fatigue occupy ranges on a single spectrum of physical discomfort, which works to regulate outputs during strenuous physical exertion. Given the similar neurobiological underpinnings of pain and fatigue, the involvement of both in the self-regulation of strenuous physical outputs, and the effects of social support on perceptions of pain and neurophysiological stress responses more generally, we hypothesised that perceptions of social support affect outputs during strenuous physical exercise by altering activity in self-regulatory mechanisms involved in perceptions of pain and fatigue. We used a between-subjects experimental design to test this hypothesis, varying participants’ social support and measuring physical outputs and perceptions of physical discomfort and exertion during a series of maximum-effort cycling bouts. Analyses showed that participants in the social support condition produced greater initial outputs and steeper declines over time, compared to controls. This effect was moderated by participant neuroticism; an important predictor of how individuals react to social support. We discuss these findings in terms of proposed causal mechanisms linking supportive, cohesive social environments with self-regulation and physical performance.

Improved arterial flow-mediated dilation after exertion involves hydrogen peroxide in overweight and obese adults following aerobic exercise training

Acute strenuous physical exertion impairs arterial function in sedentary adults. We investigated the effects of 8 weeks of regular aerobic exercise training on acute physical exertion-induced arterial dysfunction in sedentary, overweight, and obese adults. Twenty-five overweight and obese adults (BMI 30.5 ± 7.2 years) were assigned to 8 weeks of aerobic training or to a control group. Brachial artery flow-mediated dilation (FMD) was assessed before and after acute leg press exercise at weeks 0 and 8. Gluteal adipose biopsies were performed at rest and post acute leg press to measure microvessel FMD with and without nitric oxide synthase inhibition via L-nitroarginine methyl ester or hydrogen peroxide (H2O2) scavenging with Catalase. Microvessel nitric oxide and H2O2 production were assessed via fluorescence microscopy. Brachial artery dilation was reduced post acute leg press at week 0 in the aerobic exercise and control groups, but was preserved in the aerobic-exercise group post acute leg press at week 8 (P < 0.05). Post acute leg press microvessel FMD was preserved in the aerobic exercise group but impaired in the control group at week 8 (P < 0.05). Preserved dilation in the aerobic exercise group was more sensitive to H2O2 scavenging than inhibition of nitric oxide, and post acute leg press microvessel H2O2 production was increased compared with at rest (P < 0.05). Aerobic exercise prevents acute exertion-induced arterial dysfunction in overweight and obese adults via a phenotypic switch from nitric oxide-mediated dilation at rest to a predominately H2O2-mediated dilation after acute physical exertion.

Association of Level of Physical Exertion with Acute Myocardial Infarction in Bangladeshi Population

Background: Evidences suggest that heavy physical exertion can trigger the onset of acute myocardial infarction. But there have been no clean cut data in Bangladesh about the risk of myocardial infarction during and after heavy exertion. To address this question the study was conducted.Methods: It was a multicentre cross sectional study was conducted from July 2012 to June 2013 with patient of diagnosed acute myocardial infarction (AMI) admitted in department of cardiology of National Institute of Cardiovascular Diseases (NICVD), Bangabandhu Sheikh Mujib Medical University (BSMMU) and Dhaka Medical College Hospital (DMCH). From selected samples, two hours activity prior to onset of symptom of AMI was asked according to standard questionnaire. Activities were quantified on a scale from 1 to 8 metabolic equivalents (METs) according to generally accepted values. Collected data were analyzed by SPSS version 16.Results: In this study 246 patients (74 .4 percent of whom were men; mean age [±SD], 64.68 ± 7.63 years) were interviewed. The study showed that 11.38% patients were engaged in strenuous physical exertion (e” 6 METs) within two hours prior to symptom onset of AMI. Strenuous exertion group of AMI patients were all most all sedentary worker [26 (92.86%) of 28]. Most of the patients (82.14 %) of strenuous group had history of less than 8 hours work per day. Strenuous exertion group had history of longtime exertion (72.57%, 1-2 hours) than non-strenuous group (42.66%, &lt;0.5 hours). Moreover, 67.86% AMI patients of strenuous exertion group had experienced irregular exertion whereas most of the patients (64.22%) of non strenuous group had a history of regular exertion.Conclusions: The result of the study indicates that a period of strenuous physical activity is associated with increased risk of having AMI, particularly among patients of sedentary worker who have dyslipidemia and who exercise irregularly. Those who exercise regularly have lower chances of AMI as shown by the negative correlation.Cardiovasc. j. 2016; 8(2): 115-122

Exercising in a hot environment with muscle damage: effects on acute kidney injury biomarkers and kidney function

Unaccustomed strenuous physical exertion in hot environments can result in heat stroke and acute kidney injury (AKI). Both exercise-induced muscle damage and AKI are associated with the release of interleukin-6, but whether muscle damage causes AKI in the heat is unknown. We hypothesized that muscle-damaging exercise, before exercise in the heat, would increase kidney stress. Ten healthy euhydrated men underwent a randomized, crossover trial involving both a 60-min downhill muscle-damaging run (exercise-induced muscle damage; EIMD), and an exercise intensity-matched non-muscle-damaging flat run (CON), in random order separated by 2 wk. Both treatments were followed by heat stress elicited by a 40-min run at 33°C. Urine and blood were sampled at baseline, after treatment, and after subjects ran in the heat. By design, EIMD induced higher plasma creatine kinase and interleukin-6 than CON. EIMD elevated kidney injury biomarkers (e.g., urinary neutrophil gelatinase-associated lipocalin (NGAL) after a run in the heat: EIMD-CON, mean difference [95% CI]: 12 [5, 19] ng/ml) and reduced kidney function (e.g., plasma creatinine after a run in the heat: EIMD-CON, mean difference [95% CI]: 0.2 [0.1, 0.3] mg/dl), where CI is the confidence interval. Plasma interleukin-6 was positively correlated with plasma NGAL (r = 0.9, P = 0.001). Moreover, following EIMD, 5 of 10 participants met AKIN criteria for AKI. Thus for the first time we demonstrate that muscle-damaging exercise before running in the heat results in a greater inflammatory state and kidney stress compared with non-muscle-damaging exercise. Muscle damage should therefore be considered a risk factor for AKI when performing exercise in hot environments.

Valsalva retinopathy developing during Japanese cheerleading training ("ouendan").

Valsalva hemorrhagic retinopathy is characterized by retinal hemorrhages that develop after a Valsalva maneuver that consists of a forcible exhalation against a closed glottis, thereby creating a sudden increase in the intrathoracic or intraabdominal pressure. We present a patient who developed retinal and vitreous hemorrhages with multiple retinal nonperfused areas after extreme physical training with shouting on a mountainous area. This exercise was part of his training as a member of a Japanese traditional cheerleading team. Case presentation. A 19-year-old man developed an acute decrease in the vision to 0.3 in his left eye after running on hilly roads at approximately 800 m while shouting fight songs for several hours. Ophthalmoscopy showed a fresh vitreous hemorrhage that covered the entire macula and was connected to the optic disk in the left eye. The vitreous hemorrhage spontaneously resolved and an intraretinal hemorrhage and nonperfused area emerged. His visual acuity returned to 1.2. Prolonged, strenuous physical exertion with shouting during training exercises can lead to Valsalva hemorrhagic retinopathy. Several other factors, such as hot weather, altitude, and dehydration, may have played an additive role in increasing the venous pressure and hypoxia in the retinal vessels, which then caused the retinopathy.

Perceived physical exertion during healthcare work and prognosis for recovery from long-term pain in different body regions: Prospective cohort study

BackgroundThe prevalence of musculoskeletal pain is high among healthcare workers. Knowledge about risk factors at work is needed to efficiently target preventive strategies. This study estimates the prognosis for recovery from long-term musculoskeletal pain in different body regions among healthcare workers with different levels of perceived physical exertion during healthcare work.MethodsProspective cohort study among 4,977 Danish female healthcare workers responding to a baseline and follow-up questionnaire in 2005 and 2006, respectively. We defined long-term pain, short-term pain and pain-free as > 30, 1–30 and 0 days with pain during the last year, and included in the analyses only those with long-term pain at baseline in the low back (N=1,089), neck/shoulder (N=1,400) and knees (N = 579), respectively. Using cumulative logistic regression analysis, the prognosis for recovering from long-term pain at baseline to short-term pain or pain-free at follow-up in the respective body regions when experiencing moderate or light (reference: strenuous) physical exertion during healthcare work was modeled.ResultsAmong those with long-term pain at baseline 34% (low back), 29% (neck/shoulders), and 29% (knees) recovered to short-term pain at follow-up and 7% (low back), 8% (neck/shoulders), and 17% (knees) recovered to being pain-free. After adjusting for potential confounders (age, BMI, tenure, smoking status, leisure physical activity and psychosocial work conditions), light perceived physical exertion during healthcare work was associated with improved prognosis for recovery from long-term pain in the low back (OR 1.42, 95% CI 1.01 – 1.99) and neck/shoulders (OR 1.89, 95% CI 1.43 – 2.50), but not in the knees. Moderate physical exertion was not associated with improved prognosis for recovery from long-term pain for any of the body regions.ConclusionIn the present study, healthcare workers with light perceived physical exertion during healthcare work had the best prognosis for recovery from long-term pain in the low back and neck/shoulders. This suggests that efforts to reduce perceived exertion during work may improve recovery from chronic pain.

Perceived physical exertion during healthcare work and risk of chronic pain in different body regions: prospective cohort study

To estimate the risk of developing chronic musculoskeletal pain in different body regions from varying degrees of perceived physical exertion during healthcare work. Prospective cohort study among 4,977 Danish female healthcare workers responding to a baseline and follow-up questionnaire in 2005 and 2006, respectively. Using multi-adjusted logistic regression analysis, the risk of developing chronic pain (>30days last year) at follow-up in the low back, neck/shoulder, and knees-among those without pain (0days last year) in these respective body regions at baseline-from moderate and strenuous (reference: light) perceived physical exertion during healthcare work was modeled. Adjusted for age, BMI, tenure, smoking status, and leisure physical activity, strenuous perceived physical exertion during healthcare work increased the risk of chronic low back pain (OR 3.16, 95% CI 1.79-5.57) and chronic knee pain (OR 1.87, 95% CI 1.19-2.94) at follow-up among those without pain in these respective body regions at baseline. With additional adjustment for psychosocial work conditions, only the risk of developing chronic low back pain from strenuous physical exertion remained significant (OR 1.99, 95% CI 1.02-3.88). Strenuous physical exertion was not a risk factor for chronic neck pain, and moderate physical exertion was not a risk factor for chronic pain in any of the body regions. Strenuous perceived physical exertion during healthcare work is a risk factor especially for developing chronic pain in the low back. The possible preventive effect of reducing strenuous physical exertion should be tested in randomized controlled trials.

Dose–response relation between perceived physical exertion during healthcare work and risk of long-term sickness absence

An imbalance between physical work demands and physical capacity of the worker may be a risk factor for poor health. Perceived physical exertion provides information about the individual perception of the work demands relative to the capacity to perform the work. This study estimates the risk for long-term sickness absence (LTSA) from perceived physical exertion among healthcare workers. This prospective cohort study comprises 8592 Danish healthcare workers who responded to a baseline questionnaire in 2004-2005 and subsequently were followed for one year in the Danish Register for Evaluation of Marginalization (DREAM), a national register of social transfer payments. Using Cox regression hazard ratio (HR) analysis, controlled for age, gender, body mass index (BMI), smoking, tenure, leisure-time physical activity, psychosocial working conditions, and LTSA during one year prior to baseline, we modeled risk estimates of moderate and strenuous (reference: light) perceived physical exertion during healthcare work for onset of LTSA (receiving sickness absence compensation for ≥8 consecutive weeks) during 1-year follow-up. At baseline, 35.1%, 39.4%, and 25.5% of the healthcare workers experienced, respectively, light, moderate, and strenuous physical exertion during healthcare work. During follow-up, the 12-month prevalence of LTSA was 4.6%, 6.4%, and 8.9%, respectively, in these three exertion groups. A dose-response pattern between physical exertion and the risk for LTSA was found (trend test P<0.0001). In the multi-adjusted model, the risk for LTSA was 1.31 [95% confidence interval (95% CI) 1.04-1.64] for healthcare workers reporting moderate physical exertion and 1.57 (95% CI 1.23-2.01) for those reporting strenuous physical exertion, referencing those reporting light physical exertion during healthcare work. Moderate and strenuous perceived physical exertion during healthcare work increases - in a dose-response manner - the risk for LTSA. The possible preventive effect of balancing work demands with the capacity of the worker, to thereby avoid excessive physical exertion, should be tested in randomized controlled trials.

Sexual Activity and Cardiovascular Disease

Sexual activity is an important component of patient and partner quality of life for men and women with cardiovascular disease (CVD), including many elderly patients.1 Decreased sexual activity and function are common in patients with CVD and are often interrelated to anxiety and depression.2,3 The intent of this American Heart Association Scientific Statement is to synthesize and summarize data relevant to sexual activity and heart disease in order to provide recommendations and foster physician and other healthcare professional communication with patients about sexual activity. Recommendations in this document are based on published studies, the Princeton Consensus Panel,4,5 the 36th Bethesda Conference,6–10 European Society of Cardiology recommendations on physical activity and sports participation for patients with CVD,11–13 practice guidelines from the American College of Cardiology/American Heart Association14–16 and other organizations,17 and the multidisciplinary expertise of the writing group. The classification of recommendations in this document are based on established ACCF/AHA criteria (Table). View this table: Table. Applying Classification of Recommendation and Level of Evidence Numerous studies have examined the cardiovascular and neuroendocrine response to sexual arousal and intercourse, with most assessing male physiological responses during heterosexual vaginal intercourse.18–24 During foreplay, systolic and diastolic systemic arterial blood pressure and heart rate increase mildly, with more modest increases occurring transiently during sexual arousal. The greatest increases occur during the 10 to 15 seconds of orgasm, with a rapid return to baseline systemic blood pressure and heart rate thereafter. Men and women have similar neuroendocrine, blood pressure, and heart rate responses to sexual activity.24,25 Studies conducted primarily in young married men showed that sexual activity with a person's usual partner is comparable to mild to moderate physical activity in the range of 3 to …

Cognitive function following treadmill exercise in thermal protective clothing

Occupational injuries are common among firefighters who perform strenuous physical exertion in extreme heat. The thermal protective clothing (TPC) worn by firefighters inhibits normal thermoregulation, placing the firefighter at risk of hypohydration and hyperthermia that may result in cognitive decline. We tested whether cognitive function changes after treadmill exercise in TPC. In an initial study (Cog 1), ten healthy volunteers performed up to 50 min of treadmill exercise while wearing TPC in a heated room. A battery of neurocognitive tests evaluating short-term memory, sustained and divided attention, and reaction time was administered immediately before and after exercise. In a follow-up study (Cog 2), 19 healthy volunteers performed a similar exercise protocol with the battery of cognitive tests administered pre-exercise, immediately post-exercise, and serially up to 120 min after exercise. Subjects performed 46.4 ± 4.6 and 48.1 ± 3.6 min of exercise in the Cog 1 and Cog 2, respectively. In both studies heart rate approached age predicted maximum, body mass was reduced 1.0-1.5 kg, and body core temperature increased to levels similar to what is seen after fire suppression. Neurocognitive test scores did not change immediately after exercise. Recall on a memory test was reduced 60 and 120 min after exercise. The mean of the 10 slowest reaction times increased in the 120 min after exercise. Fifty minutes of treadmill exercise in TPC resulted in near maximal physiologic strain but alterations in neurocognitive performance were not noted until an hour or more following exercise in TPC.

Traffic-related Air Pollution and Blood Pressure in Elderly Subjects With Coronary Artery Disease

Associations between blood pressure (BP) and ambient air pollution have been inconsistent. No studies have used ambulatory BP monitoring and outdoor home air-pollutant measurements with time-activity-location data. We address these gaps in a study of 64 elderly subjects with coronary artery disease, living in retirement communities in the Los Angeles basin. Subjects were followed up for 10 days with hourly waking ambulatory BP monitoring (n = 6539 total measurements), hourly electronic diaries for perceived exertion and location, and real-time activity monitors (actigraphs). We measured hourly outdoor home pollutant gases, particle number, PM2.5, organic carbon, and black carbon. Data were analyzed with mixed models controlling for temperature, posture, actigraph activity, hour, community, and season. We found positive associations of systolic and diastolic BP with air pollutants. The strongest associations were with organic carbon (especially its estimated fossil-fuel- combustion fraction), multiday average exposures, and time periods when subjects were at home. An interquartile increase in 5-day average organic carbon (5.2 microg/m) was associated with 8.2 mm Hg higher mean systolic BP (95% confidence interval = 3.0-13.4) and 5.8 mm Hg higher mean diastolic BP (3.0-8.6). Associations of BP with 1-8 hour average air pollution were stronger with reports of moderate to strenuous physical exertion but not with higher actigraph motion. Associations were also stronger among 12 obese subjects. Exposure to primary organic components of fossil fuel combustion near the home were strongly associated with increased ambulatory BP in a population at potential risk of heart attack. Low fitness or obesity may increase the effects of pollutants.

Wood smoke exposure induces a pulmonary and systemic inflammatory response in firefighters

Epidemiological studies report an association between exposure to biomass smoke and cardiopulmonary morbidity. The mechanisms for this association are unclear. The aim of the present study was to characterise the acute pulmonary and systemic inflammatory effects of exposure to forest fire smoke. Seasonal forest firefighters (n = 52) were recruited before and/or after a day of fire-fighting. Exposure was assessed by questionnaires and measurement of carbon monoxide levels (used to estimate respirable particulate matter exposure). The pulmonary response was assessed by questionnaires, spirometry and sputum induction. Peripheral blood cell counts and inflammatory cytokines were measured to define the systemic response. Estimated respirable particulate matter exposure was high (peak levels >2 mg x m(-3)) during fire-fighting activities. Respiratory symptoms were reported by 65% of the firefighters. The percentage sputum granulocytes increased significantly from 6.5 to 10.9% following fire-fighting shifts, with concurrent increases in circulating white blood cells (5.55x10(9) to 7.06x10(9) cells x L(-1)) and band cells (0.11x10(9) to 0.16x10(9) cells x L(-1)). Serum interleukin (IL)-6, IL-8 and monocyte chemotactic protein-1 levels significantly increased following fire-fighting. There were no changes in band cells, IL-6, and IL-8 following strenuous physical exertion without fire-fighting. There was a significant association between changes in sputum macrophages containing phagocytosed particles and circulating band cells. In conclusion, acute exposure to air pollution from forest fire smoke elicits inflammation within the lungs, as well as a systemic inflammatory response.

Exertional Rhabdomyolysis in 8 Division I Female Lacrosse Athletes: A Case Series

XERTIONAL RHABDOMYOLYSIS (ER) is a complication of exercise that can be fatal if not recognized and treated appropriately. It is defined as the dissolution of skeletal muscle that produces a nonspecific clinical syndrome that causes leakage of toxic intracellular contents into the circulatory system. 1 This dissolution is manifested by increased extracellular myoglobin, potassium, phosphate, creatine kinase (CK), or urate that is released by the damaged myocytes. Release of these products into the bloodstream can result in decreased cellular function, renal failure, and even death in severe cases. 2 Most cases of ER are a result of muscle overexertion, alcohol abuse, muscle compression, or the use of certain medications. Initially, ER presents with symptoms similar to those observed with cases of delayed-onset muscle soreness (DOMS). Both DOMS and ER can occur after moderately strenuous physical exertion. Because of the similar manifestations of DOMS and ER, it is essential to obtain a proper history of an athlete’s activity levels, hydration levels, and medical history to ensure a proper course of treatment. 2 The pathophysiology of ER is a direct result of the energy requirements exceeding the athlete’s ability to produce adenosine triphosphate (ATP). As these requirements exceed production, the ATP-dependent sodium-potassium pump begins to fail, which results in an electrochemical disruption across the cell membrane and increased intracellular calcium levels. This increase initiates normally dormant enzymes that destroy the cell membrane, resulting in leakage of intracellular contents into the local circulation. ER is typically characterized by the release of intracellular contents into the local circulatory system that are signaled by an elevation in CK levels. 1,3 There are no toxic properties in CK, but elevated CK levels serve as a marker for increased permeability of muscle membranes. Although slightly elevated levels of CK might be observed in cases of DOMS, ER alone results in gross elevations of serum CK. 1 Serious complications of ER include renal failure, cardiac dysrhythmias, compartment syndrome, disseminated intravascular coagulation, lactic acidosis, and possibly death. 4 These can all be avoided with early recognition and treatment.

An adolescent girl with Meyer-Betz syndrome

Idiopathic paroxysmal rhabdomyolysis indicating a classical triad of symptoms consisting of muscle pain, weakness, and discolored urine is known as "Meyer-Betz syndrome". It may result in acute renal failure due to precipitation of the myoglobin casts in the tubuli or to the direct toxic effects of myoglobin to the tubular epithelium. On the other hand, outcome may be uneventful. In this study, we reported the case of a 16-year-old girl who was admitted with red-colored urine after a slight exertion. She had tenderness and weakness in upper parts of her legs and bilateral flank pain. She had a positive urine dipstick test for heme despite absent red cells on microscopic examination. White cell count, liver function tests, serum creatine kinase (CK), lactate dehydrogenase (LDH), and urine myoglobin levels were raised. All metabolic tests were in normal ranges and EMG was normal. A muscle biopsy performed after recurrent exertional rhabdomyolysis attacks demonstrated normal findings and ruled out metabolic disorders. At the time of attacks, hydration along with alkalinization was applied and she did not experience renal failure. She was advised to avoid strenuous physical exertion and had an uneventful outcome for the last 5 months. We reported the clinical course and follow-up of an adolescent girl with Meyer-Betz syndrome.

Smoking attenuates regular aerobic exercise benefits to episodic free recall immediately following strenuous physical activity

AbstractThe present study was designed to evaluate the extent to which free recall performance is influenced by competing demands on physiological resources dependent on blood‐oxygen levels. Fifty‐six healthy young adults (mean age=20 years) were allocated to groups (n1–4=14) according to their level of exercise (more than 6 h aerobic exercise per wk, or sedentary1Here sedentary refers to individuals with no regular exercise routines .) and smoking (more than 10 cigarettes per day, or none) behaviour. Participants performed two free recall tasks, one under normal physically inactive conditions and the other immediately following strenuous physical exertion (a step‐up test for 2 min). We predicted that recall would suffer following strenuous physical activity among smoking aerobic exercisers. We reasoned this would be due to the oxygen‐carrying capacity of the blood being compromised in this group by higher levels of smoking‐related carbon monoxide in the blood stream. The results supported this prediction. We interpret our findings according to a resource model of cognitive function, mediated by physiological mechanisms. Copyright © 2004 John Wiley &amp; Sons, Ltd.

Sexual activity in patients with angina.

COITAL ANGINA IS ANGINA THAT occurs during the minutes or hours following sexual activity. More than 6 million individuals in the United States experience angina pectoris. Coital angina appears to represent less than 5% of all anginal attacks. For various reasons, fewer middle aged or older women engage in sexual activity than age-matched men. Accordingly, the prevalence of coital angina is higher in men than in women. The comparative physical demands of sexual activity in men and women are unknown. Frequency of coitus diminishes with age in both women and men, especially after the onset of coronary artery disease, which occurs some 10 years later in women than in men. Coital angina is rare in patients who do not have angina during strenuous physical exertion. It is more prevalent in sedentary individuals with severe coronary artery disease who experience angina with minimal physical activity. Among these sedentary individuals, myocardial oxygen demand during coitus may exceed that during customary activities of daily living; for these individuals, sex may be a provocative test.

Mast-cell stabilising agents to prevent exercise-induced bronchoconstriction.

Exercise-induced bronchoconstriction (or asthma) following strenuous physical exertion is common and can cause sub-optimal performance, symptoms such as cough, dyspnea, wheeze, chest tightness, and can lead people to avoid physical activity. Management focuses on prevention with pre-exercise treatment using various pharmacologic agents. Mast cell stabilizing agents are effective in attenuating exercise-induced bronchoconstriction but their effectiveness compared to bronchodilator agents is unclear. To quantitatively compare the effects of inhaling a single dose of either mast cell stabiliser - nedocromil sodium or sodium cromoglycate - to a single dose of short acting beta-agonists or anti-cholinergic agents - atropine or ipratropium bromide - prior to a strenuous exercise challenge in participants with asthma who are at least 6 years of age and suffer from reproducible exercise-induced bronchoconstriction. The review also compares the effects between a short acting beta-agonist alone to a combination of a short acting beta-agonist + mast cell stabiliser. We searched the Cochrane Airways Group ASTHMA and WHEEZ* trials register, Cochrane CENTRAL, Current Contents, review articles, textbooks and reference lists of articles. We also contacted the drug manufacturer and primary authors for additional citations. Randomised trials comparing a single prophylactic dose of a mast cell stabiliser to a short acting beta-agonist, anti-cholinergic agent, or a short acting beta-agonist alone to a combination of short acting beta-agonist plus a mast cell stabiliser to prevent exercise-induced bronchoconstriction in asthmatics over six years old. The exercise challenge had to conform to acceptable standards and pulmonary function (PFT) reported as percent decrease from baseline of FEV1 or peak flow. Complete protection (maximum % fall PFT <15% post-exercise) and clinical protection (50% improvement over placebo effect) measures were included. Trial inclusion and quality assessments were conducted independently by two reviewers using standardised forms. A second reviewer confirmed data extraction and calculations. Attempts were made to contact study authors. The pooled estimate involving continuous pulmonary function measures are reported as a weighted mean difference (WMD), dichotomous data as an odds ratio (OR), both with 95% confidence intervals (95%CI) using a random effects model. Heterogeneity tests for pooled results were performed. Twenty-four trials (518 participants) conducted in 13 countries between 1976 and 1998 were included. All drugs were effective at attenuating the exercise-induced bronchoconstriction response but to varying degrees even within the same individual. Compared to anti-cholinergic agents, mast cell stabilisers were somewhat more effective at attenuating bronchoconstriction. On average the maximum fall on MCS was reduced to 7.1% compared to 13.8% on AC ( WMD = 6.7%; 95% CI: 3.3 to 10.0), provided more individuals with complete protection (73% vs 56%; OR = 2.2; 95% CI: 1.3 to 3.7) and clinical protection (73% vs 52%; OR = 2.7; 95% CI: 1.1 to 6.4). There were no subgroup differences based on age, severity, or study quality, and no adverse effects were reported for either agent group. When compared to short acting beta-agonists mast cell stabilisers were not as effective at preventing deterioration. On average the maximum fall on MCS was 11.2% compared to 4.3% on beta agonists ( WMD = 6.8%; 95% CI: 4.5 to 9.2). MCS provided fewer individuals with complete protection (66% vs 85%; OR = 0.3; 95% CI: 0.2 to 0.5) or clinical protection (55% vs 77%; OR = 0.4; 95% CI: 0.2 to 0.8). There were no significant subgroup differences based on age, severity, drug, delivery, or study quality. A non-significant difference in side effects was demonstrated with 11% of short acting beta-agonist patients experiencing side effects compared to 3% of those receiving mast cell stabilisers (OR = 0.2; 95% CI: 0.0 to 8.2). Combining masta-agonist patients experiencing side effects compared to 3% of those receiving mast cell stabilisers (OR = 0.2; 95% CI: 0.0 to 8.2). Combining mast cell stabilisers with a short acting beta-agonist did not produce significant advantages to pulmonary function over short acting beta-agonists alone. On average the maximum fall on SABA only was reduced to 5.3% compared to 3.5% on the combination ( WMD = 1.8%; 95% CI: -1.1 to 4.6). Beta-agonists alone provided fewer individuals with complete protection (68% vs 80%; OR = 0.5; 95% CI: 0.2 to 1.4) or clinical protection (70% vs 86%; OR=0.4; 95% CI: 0.1 to 1.2) but the difference did not reach significance (p=0.17). There were no subgroup differences. In a population of stable asthmatics short acting beta-agonists, mast cell stabilisers, or anticholinergics will provide a significant protective effect against exercise-induced bronchoconstriction with few adverse effects. On average, SABAs resulted in more effective attenuation than mast cell stabilisers, while mast cell stabilisers were more effective than anti-cholinergic agents. Combining SABA and mast cell stabilisers may be appropriate in selected cases. The variability in the individual degree of response to these drugs in multi arm trials suggests clinicians and patients work together to identify the most effective prophylactic therapy.

Triggers of subarachnoid hemorrhage: role of physical exertion, smoking, and alcohol in the Australasian Cooperative Research on Subarachnoid Hemorrhage Study (ACROSS).

Unaccustomed strenuous physical exertion can trigger myocardial infarction, but little is known about the mechanisms precipitating subarachnoid hemorrhage (SAH). We identified all cases of first-ever SAH among the combined populations (2.8 million) of 4 urban centers in Australia and New Zealand. Information on the type, time, and intensity of exposures in the 26 hours before the onset of SAH was ascertained by structured interviews. We used the case-crossover technique to assess the risk of SAH associated with transient exposures of moderate to extreme physical exertion, heavy cigarette smoking, and binge alcohol consumption. We registered 432 first-ever cases of SAH (62% women; mean age, 56.5 years). A definite time of onset of SAH was established for 393 patients (91%), and information on the levels of physical activity in the preceding 26 hours was obtained in 338 (78%). Of these patients, 19% engaged in moderate to extreme exertion (>or=5 metabolic equivalents) in the 2 hours before SAH, which was associated with a tripling in the risk of SAH (odds ratio [OR], 2.7; 95% CI, 1.6 to 4.6). There was no evidence of any association between heavy cigarette smoking or binge drinking and risk of SAH in the subsequent 2 hours (OR, 1.1; 95% CI, 0.4 to 3.7; and OR, 0.41; 95% CI, - infinity to 5.3). Habitual exercise did not appear to alter the risk of SAH associated with moderate to extreme exertion. Moderate to extreme physical exertion tripled the risk of SAH, but there was no association between transient heavy smoking or binge drinking and risk of SAH. These data suggest that heavy physical activity may trigger SAH.

Work at high altitude and oxidative stress: antioxidant nutrients

A significant portion of the world's geography lies above 10,000 feet elevation, an arbitrary designation that separates moderate and high altitude. Although the number of indigenous people living at these elevations is relatively small, many people travel to high altitude for work or recreation, exposing themselves to chronic or intermittent hypoxia and the associated risk of acute mountain sickness (AMS) and less frequently, high altitude pulmonary edema (HAPE) and high altitude cerebral edema (HACE). The symptoms of AMS (headache, nausea, anorexia, fatigue, lassitude) occur in those who travel too high, too fast. Some investigators have linked the development of these symptoms with the condition of altered blood–brain barrier permeability, possibly related to hypoxia induced free radical formation. The burden of oxidative stress increases during the time spent at altitude and may even persist for some time upon return to sea level. The physiological and medical consequences of increased oxidative stress engendered by altitude is unclear; indeed, hypoxia is believed to be the trigger for the cascade of signaling events that ultimately leads to adaptation to altitude. These signaling events include the generation of reactive oxygen species (ROS) that may elicit important adaptive responses. If produced in excess, however, these ROS may contribute to impaired muscle function and reduced capillary perfusion at altitude or may even play a role in precipitating more serious neurological and pulmonary crisis. Oxidative stress can be observed at altitude without strenuous physical exertion; however, environmental factors other than hypoxia, such as exercise, UV light exposure and cold exposure, can also contribute to the burden. Providing antioxidant nutrients via the diet or supplements to the diet can reduce oxidative stress secondary to altitude exposure. In summary, the significant unanswered question concerning altitude exposure and antioxidant supplementation is when does oxidative stress become potentially damaging enough to merit antioxidant therapy and conversely, what degree of oxidative stress is necessary to foster the adaptive response of altitude exposure?