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The significance of abnormal systolic blood pressure response during supine ergometer exercise and postexercise in ischemic heart disease, studied by exercise radionuclide ventriculography.

The prognostic value of abnormal postexercise systolic blood pressure (BP) response has not been investigated. Therefore, the significance of abnormal BP response during exercise and postexercise was examined in 169 patients with ischemic heart disease subjected to supine ergometer exercise gated equilibrium radionuclide ventriculography, coronary arteriography, and follow up averaging 3.6 years. Abnormal BP response during exercise (exertional "hypotension") was defined as 1) a failure of BP to rise by at least 11 mmHg or 2) an initial rise in BP but subsequent fall by more than 10 mmHg during exercise. Abnormal BP response during postexercise (postexercise "hypertension") was defined as an increase of more than 10 mmHg above the peak exercise BP. Of 169 patients, 51 (30%) had an abnormal BP response. Four types of BP response were identified: exertional "hypotension" (group 1a, n = 11), postexercise "hypertension" (group 1b, n = 30), exertional "hypotension" with postexercise "hypertension" (group 1c, n = 10) and normal BP response (group 2, n = 118). Both average exercise duration and peak heart rate were significantly lower in groups 1a, 1b and 1c than in group 2. The severity of exercise ST-segment depression was greater in groups 1b and 1c than in group 2. However, there was no significant difference in the severity of exercise ST-segment depression between group 1a and group 2. A decline in ejection fraction occurred more frequently in groups 1b and 1c than in group 2. Patients in groups 1a, 1b and 1c had more extensive coronary artery disease (CAD) than did patients in group 2. Medically treated patients with an abnormal BP response (groups 1a, 1b and 1c) had a poorer prognosis than did those with a normal BP response (group 2). These findings suggest that an abnormal BP response during supine exercise is infrequent, but is usually associated with impaired exercise tolerance and severe CAD. An abnormal postexercise BP response is also infrequent, but is more closely associated with evidence of myocardial ischemia and global left ventricular dysfunction than exertional "hypotension". In conclusion, postexercise "hypertension" has the same value as exertional "hypotension" as a predictor of poor prognosis.

Angina Pectoris

Exercise thallium-201 tomographic scintigraphy in the diagnosis of coronary artery disease: emphasis on the effect of exercise level.

Exercise thallium-201 imaging using single-photon emission computed tomography (SPECT) was evaluated in 154 patients with angiographically documented coronary artery disease (CAD) and in 25 normal subjects. Of the 154 patients with CAD, 134 (87%) had abnormal thallium images. By contrast, only 77 (50%) patients had ischemic ST-segment depression (p < 0.001). Among 25 normal subjects, 20 had normal exercise SPECT images. The specificity of exercise SPECT imaging (80% or 20/25) in excluding patients with CAD was not significantly higher than that of exercise electrocardiography (76% or 19/25). For the detection of individual vessel involvement by analysis of territories of perfusion abnormalities, the sensitivity and specificity of exercise SPECT were 72% and 96% for the left anterior descending, 78% and 85% for the right coronary, and 47% and 98% for the left circumflex artery. Ninety (group 1) of the 154 patients with CAD achieved adequate exercise end points (ischemic ST-segment depression or > 85% of maximal predicted heart rate) and 64 (group 2) did not. Exercise SPECT showed significantly more perfusion abnormalities in group 1 than in group 2 (96% vs 75%, p < 0.001). We conclude that: (1) exercise SPECT thallium imaging is more sensitive than exercise electrocardiography for detecting patients with CAD; (2) the sensitivity of the test is affected by the level of exercise; and (3) it is valuable in the identification of individual vessel involvement.

Coronary Disease

Accuracy of RPE from graded exercise to establish exercise training intensity.

The purpose of this investigation was to examine the accuracy of an exercise intensity prescription based upon perceptual responses obtained during a graded exercise test. Fifteen physically active men completed a graded exercise test (GXT) on a motor driven treadmill. Heart rate (HR), oxygen uptake (VO2), and RPE were measured each minute. An RPE intensity prescription was calculated as 75% of heart rate reserve from the GXT heart rate and RPE data. A minimum of 48 h later the subjects completed 10 min of exercise (EXT) on a level treadmill at the prescribed RPE. The subjects set the treadmill speed to elicit an exercise intensity equal to the prescribed perception of effort. There were significant mean differences (P < 0.05) in heart rate between the GXT (161.8 +/- 1.3) and EXT (154.9 +/- 4.5). However, by minute 6 the subjects were within four beats.min-1 of the target heart rate. There were no significant differences (P > 0.05) between GXT and EXT for VO2 (36.1 +/- 5.2, 33.1 +/- 6.4) and VE (64.1 +/- 10.8, 58.4 +/- 13.5) respectively. The present investigation demonstrates that a subject's perceptual response to a GXT can be used to accurately prescribe exercise intensity during level treadmill running. The intensity selected was within a typical range used for exercise prescription. The advantage of RPE as a method of exercise prescription is that an individual does not need to stop during exercise and measure a heart rate, but can make pace adjustments while exercising based solely upon the perception of effort.

Adult

[Exercise-induced ST segment shift in vasospastic angina with special reference to comparisons between treadmill and bicycle ergometer exercise testings].

To assess the difference between cardiovascular responses to treadmill exercise (TM) and those to bicycle ergometer exercise (EM) in provoking coronary spasm, we compared the ST segment shifts (elevation or depression) during TM and EM in 67 patients with vasospastic angina. Coronary artery spasm was demonstrated on angiography. Both TM and EM were performed on the same day during a medication-free period. For both tests, multistage, symptom-limited exercise protocols were used; EM in the morning and TM in the afternoon. The results obtained were as follows: 1. Rate-pressure products at peak exercise during TM and EM were similar. Systolic blood pressure levels at peak exercise were higher during EM than during TM (p < 0.01). The patients' heart rates at peak exercise were higher during TM than during EM (p < 0.01). Diastolic blood pressure levels at peak exercise were higher during EM than during TM (p < 0.05). 2. Exercise-induced ST elevation occurred more frequently with TM than with EM (19% vs 9%, p < 0.05). 3. Exercise-induced ST depression was provided in 27 patients during TM and in 13 during EM (40% vs 19%, p < 0.01). Among 45 patients without significant lesions, ST depression occurred in 19 during TM, but in only 7 during EM (42% vs 16%, p < 0.01). In conclusion, coronary spasm seemed to occur more frequently with TM than with EM. The mechanism causing such difference remains to be elucidated, however, we speculate that the difference between TM and EM as to enhanced autonomous nervous system activity and coronary perfusion exercise may be related to the difference in the incidence of coronary spasm.

Aged

Detecting asymptomatic coronary artery disease using routine exercise testing and exercise thallium scintigraphy in patients with atherosclerotic vascular disease.

ECG-monitored exercise testing has been proposed as a relatively inexpensive and effective means of screening for asymptomatic coronary artery disease in patients presenting for peripheral vascular surgery. Despite the fact that exercise thallium scintigraphy is also dependent on the patient's ability to exercise, using this test in conjunction with ECG-monitored exercise testing may enhance sensitivity and specificity of non-invasive evaluation. Thirty-two patients were subjected to ECG-monitored exercise testing, exercise thallium scintigraphy and coronary angiography. The sensitivity of ECG-monitored exercise testing for detecting coronary artery disease was calculated at 81.8% and the specificity at 87.5%, while the figures for exercise thallium scintigraphy were 73.1% and 33.3% respectively. Using these two methods in combination yielded a predictive accuracy of 90.6%. The only advantage of exercise thallium scintigraphy over exercise ECG appears to be in patients in whom the latter test could not be interpreted or was non-diagnostic.

Adult

Thermic effect of food at rest, during exercise, and after exercise in lean and obese men of similar body weight.

The thermic effect of food at rest, during 30 min of cycle ergometer exercise, and after exercise was studied in eight lean (mean +/- SEM, 10 +/- 1% body fat, hydrostatically-determined) and eight obese men (30 +/- 2% body fat). The lean and obese mean were matched with respect to age, height, weight, and body mass index (BMI) to determine the relationship between thermogenesis and body composition, independent of body weight. All men were overweight, defined as a BMI between 26-34, but the obese had three times more body fat and significantly less lean body mass than the lean men. Metabolic rate was measured by indirect calorimetry under four conditions on separate mornings, in randomized order, after an overnight fast: 3 h of rest in the postabsorptive state; 3 h of rest after a 750-kcal mixed meal (14% protein, 31.5% fat, and 54.5% carbohydrate); during 30 min of cycling and for 3 h post exercise in the postabsorptive state; and during 30 min of cycling performed 30 min after the test meal and for 3 h post exercise. The thermic effect of food, which is the difference between postabsorptive and postprandial energy expenditure, was significantly higher for the lean than the obese men under the rest, post exercise, and exercise conditions: the increments in metabolic rate for the lean and obese men, respectively, were 48 +/- 7 vs. 28 +/- 4 kcal over 3 h rest (P less than 0.05); 44 +/- 7 vs. 16 +/- 5 kcal over 3 h post exercise (P less than 0.05); and 19 +/- 3 vs. 6 +/- 3 kcal over 30 min of exercise (P less than 0.05). The thermic effect of food was significantly negatively related to body fat content under the rest (r = -0.55), post exercise (r = -0.66), and exercise (r = -0.58) conditions. The results of this study indicate that for men of similar total body weight and BMI, body composition is a significant determinant of postprandial thermogenesis; the responses of obese are significantly blunted compared with those of lean men.

Adipose Tissue

Gas exchange, metabolite status and excess post-exercise oxygen consumption after repetitive bouts of exhaustive exercise in juvenile rainbow trout.

Juvenile rainbow trout (approximately 6 g) were exercised to exhaustion in two 5 min bouts given 6 h apart. Resting levels of whole-body lactate and glycogen were restored prior to the second bout. The rate of O2 consumption increased about threefold 5 min after each bout of exercise, while recovery time decreased from 4 h after the first bout to 2-3 h after the second. The excess post-exercise oxygen consumption, i.e. 'oxygen debt', was significantly reduced by 40% after the second exercise bout, despite almost identical rates of lactate clearance and glycogen resynthesis. The rates of CO2 and ammonia excretion increased sixfold and threefold, and recovery times decreased from 4-6 h to 3 h and from 3 h to 1.5 h, respectively. After the first bout, whole-body lactate levels peaked at 5 min post-exercise at about 8.5 times pre-exercise levels. After the second bout, lactate levels peaked at 0 min post-exercise and fell more rapidly during recovery. Whole-body glycogen levels decreased by 70% and 80% and ATP levels decreased by 75% and 65% after the first and second bouts, respectively, while glucose levels increased about 1.5-fold immediately after both bouts. Creatine phosphate levels decreased by 70% and 80% after the first and second bouts, respectively. After 6 h of recovery, creatine phosphate levels were higher after the second bout than after the first. These findings suggest that exhaustive exercise may cause a 'non-specific' increase in metabolic rate not directly related to the processing of metabolites, which is reduced upon a subsequent exercise bout. This is in contrast with the classical 'oxygen debt hypothesis', which states that the oxygen debt and lactate clearance are linked. Furthermore, it appears that two sequential exercise bouts are sufficient to induce a 'training effect', i.e. improved rates of metabolic recovery.

Adenosine Triphosphate

Effect of 6 d of exercise training on responses to maximal and sub-maximal exercise in middle-aged men.

Nine sedentary men (53 +/- 3 yr) were studied before and after 6 d of endurance exercise training to determine the effects on maximal oxygen uptake (VO2max), and on the heart rate, blood pressure, and metabolic responses to a standard bout of steady-state sub-maximal exercise. The subjects exercised approximately 1 h.d-1 at about 68% of VO2max. The 6-d protocol elicited no improvement in VO2max (2.50 +/- 0.14 before vs 2.58 +/- 0.15 l.min-1 after training). Heart rates were significantly lower by 5 to 8 b.min-1, systolic blood pressures were reduced by 16 to 19 mm Hg, and blood lactate concentrations were 25 to 35% less at the same exercise intensities (60, 70, and 80% of VO2max) after 6 d of exercise. Rate pressure product was about 15% lower at the same exercise intensity after 6 d of training (P less than 0.05). The respiratory exchange ratio during submaximal exercise was 0.02 to 0.04 units lower (P less than 0.05; P less than 0.01) after 6 d of exercise, indicating a shift in substrate utilization favoring fat oxidation. These findings suggest that short-term endurance training can induce heart rate, blood pressure, and metabolic adaptations to sub-maximal exercise before there is a significant increase in VO2max in sedentary, middle-aged men who are capable of vigorous exercise.

Blood Pressure

Estimation of exercise capacity from oxygen consumption in the recovery phase of submaximal exercise.

We analyzed the transient response of oxygen consumption (VO2) after the sudden termination of exercise. The study population consisted of 20 male athletes (age 13 to 15.9 years) and 87 male patients, 59 of whom (age 4.8 to 17.8 years) were considered to be normal subjects, and 28 of whom (age 6 to 14.8 years) had restricted physical activity because of underlying heart diseases (restricted group). The exercise tests were performed according to Bruce's protocol and terminated at signs of exhaustion. As soon as exercise ceased, the examinee sat on a chair and took rested completely. VO2 was measured every 30 seconds throughout the test. We characterized the rate of the initial decay of the VO2 transient as the ratio of the 30 second VO2 right after the exercise to that at the end of the exercise (Irv). This index did not differ significantly among the groups. On the other hand, Exc, the Irv normalized by the end-exercise VO2, was a sensitive index for separating the restricted group from the control and athlete groups. Should the Exc remain sensitive enough to quantify exercise capacity regardless of the intensity of the exercise imposed, even the submaximal exercise test should enable us to safely evaluate the exercise capacity of patients with impaired cardiac function.

Adolescent

Exercise intensity determines and climatic conditions modify the severity of exercise-induced asthma.

Recent studies have shown some evidence that exercise-induced asthma (EIA) may not be entirely explained by respiratory heat loss (RHL). We investigated the interrelationship between heat exchange, exercise intensity and EIA. In order to differentiate between the effects of RHL and exercise intensity, we arranged for tests to be performed with the same RHL, but with different intensities of exercise and inspired air conditions. Each of 8 asthmatic children exercised twice in random order for 6 min on a cycle ergometer. One test consisted of exercise performed at a greater level of effort while breathing room air, mean (+/- SE) air conditions being 25.0 +/- 0.4 degrees C and 15.7 +/- 0.2 mg H2O/L. The other test was performed at a lesser level of effort while breathing cold (0.0 +/- 0.5 degrees C) and dry air (O mg H2O/L). The mean ratio of minute ventilations in the 2 exercise tests was 1.78 +/- 0.03, but the RHL was similar in both tests. The EIA after the exercise at the greater level was more severe than after the lesser level, the percent fall in FEV2 from baseline being 36 +/- 7% and 21 +/- 5%, respectively (p less than 0.025). We conclude that the exercise level has a major role in determining the severity of EIA and that climatic conditions act as modifying factors.

Adolescent

Effects of anticipation, prior-exercise, and breathing frequency to ventilatory response during step exercise: a preliminary study.

We examined the effects of anticipation, prior-exercise, and restricted breathing frequency on the ventilatory transient response to bicycle step exercise (75 W, 4 min, 50 rpm), i.e., 1) whether the increase of work rate was anticipated by the subject or not, 2) whether the exercise was preceded by light exercise (25 W), or rest, and 3) whether the exercise entrained the breathing frequency (f: 12.5/min, or 25/min) or not (voluntary). The corresponding step-on exercise was randomly performed at least two to five times by one adult male subject. As a result, a) the initial rapid ventilatory component, phase 1, was not observed when initiated from light exercise, whereas the overshot phase 1 was observed from rest in anticipation and voluntary breathing frequency condition due to the rapid increase of tidal volume; b) compared with the anticipation condition, the phase 1 response of VE in the non-anticipation condition was slower with prior-rest, and not with prior-light exercise; and c) the restriction of the breathing frequency for entraining the exercise rhythm did not affect the initial rapid response, but decreased the fluctuation of VE in the steady state, compared to the condition of voluntary breathing frequency.

Adult

Joint exercises in elderly persons with symptomatic osteoarthritis of the hip or knee. Performance patterns, medical support patterns, and the relationship between exercising and medical care.

A total of 110 community-living elderly persons with chronic hip and/or knee pain, all of whom met American College of Rheumatology classification criteria for osteoarthritis (OA), were interviewed to obtain information about their performance of therapeutic joint exercises and exercise-related medical care. Although exercises are considered standard treatment for OA and 96% of subjects had seen a physician for the problem, fewer than half had received medical advice to exercise and very few had received thorough exercise-related teaching and monitoring. Arthritis specialists provided significantly more support for exercising than primary care physicians. Forty percent of the total sample and 63% of those advised by a physician to exercise were making some attempt to do so; however, only 10% were exercising in a manner that might be expected to achieve maximum therapeutic benefit. Supportive medical care was highly related to frequency of exercising.

Aged

Exercise echocardiography after stabilization of unstable angina: correlation with exercise thallium-201 single photon emission computed tomography.

The diagnostic usefulness of predischarge exercise echocardiography in 35 patients with unstable angina who responded to medical therapy was correlated with exercise thallium-201 single photon emission computed tomography (TI-SPECT) performed, on the average, three days after the exercise echocardiography. None of the patients had myocardial infarction prior to hospitalization or before TI-SPECT and none had left bundle-branch block on their rest electrocardiogram (ECG). Exercise echocardiography was positive in 21 patients and TI-SPECT in 24. The results of the two techniques were concordant in 28 of 35 patients (agreement = 80%, k = 0.57 +/- 0.14, p less than 0.001). Wall-by-wall comparison of the distribution of exercise-induced wall motion abnormalities with reversible thallium defects showed complete or partial correlation in all of 19 patients in whom both the tests were positive. A positive exercise ECG and positive exercise echocardiography identified 11 of 11 patients with angiographically verified significant coronary artery disease (CAD) and 11 of 12 patients (92%) with positive TI-SPECT. Thus, exercise echocardiography is a valuable addition to routine predischarge exercise test in the noninvasive diagnosis of myocardial ischemia and shows a good correlation with TI-SPECT in detecting and localizing ischemia in patients with unstable angina stabilized on medical therapy.

Angina, Unstable

Use of maximal bicycle exercise testing with respiratory gas analysis to assess exercise performance in patients with congestive heart failure secondary to coronary artery disease or to idiopathic dilated cardiomyopathy.

Analysis of respiratory gases during maximal treadmill exercise testing has been used in patients with congestive heart failure (CHF) to detect the lactate threshold, presumed to reflect the onset of skeletal muscle underperfusion, and maximal oxygen consumption (VO2), the point at which VO2 plateaus with increasing work due to exhaustion of peripheral oxygen delivery capacity. To determine if this approach is also useful during maximal bicycle exercise testing, ventilatory, hemodynamic and systemic lactate responses to bicycle exercise were measured in 48 patients with CHF. Ventilatory responses also were assessed in 12 normal subjects. Exercise increased VO2 to 24.8 +/- 3.9 ml/min/kg in normal subjects and 13.9 +/- 3.7 ml/min/kg in patients with CHF (p less than 0.001). In all but 1 patient the VO2 increment over the last 3 minutes of exercise was comparable to that in normal subjects exercising over identical work times, suggesting that maximal VO2 was not achieved. Moreover, in patients who exercised for less than 6 minutes, a ventilatory lactate threshold could not be identified. In the 33 patients who exercised longer, a ventilatory lactate threshold was identified in 31 and correlated well (r = 0.81) with blood lactate threshold, as defined by the VO2 at which lactate increased 5 mg/dl over rest levels. However, the 95% confidence limit for predicting blood lactate threshold from ventilatory data was +/- 200 ml/min, a large range relative to the measured ventilatory threshold (570 +/- 132 ml/min). These data suggest that in patients with CHF, respiratory gas analysis during maximal bicycle exercise cannot be used to measure maximal VO2 and provides only a general index of blood lactate behavior.

Cardiac Output

Normalization of upright exercise hemodynamics and improved exercise capacity one year after orthotopic cardiac transplantation.

The mechanisms of improved functional capacity over the first year after cardiac transplantation are not well studied. To assess the contribution of cardiac changes to this improvement, the serial evolution of upright rest and exercise hemodynamics during graded upright bicycle exercise was studied in 17 patients at 3 and 12 months after heart transplantation. Heart rate responsiveness, reflected by rapid heart rate acceleration on sitting and rapid deceleration after exercise, developed in the first year. Pulmonary capillary wedge pressure was lower at 1 year, both at rest and at peak exercise (10 +/- 3 vs 13 +/- 5 mm Hg at rest supine and 14 +/- 6 vs 18 +/- 8 mm Hg at peak exercise, p less than 0.05). Similarly, right atrial pressures were also significantly lower at 1 year (4 +/- 2 vs 6 +/- 3 mm Hg at rest supine and 6 +/- 5 vs 11 +/- 5 mm Hg at peak exercise, p less than 0.05). Cardiac index at peak exercise was greater at 12 months (6.4 +/- 1.3 vs 5.8 +/- 0.8 liters/min/m2, p less than 0.05), mediated primarily by higher exercise heart rate (135 +/- 16 vs 125 +/- 12 beats/min, p less than 0.05). In the first year after heart transplantation, improved rest and exercise hemodynamics and heart rate responsiveness contribute significantly to the improved functional capacity observed in these patients.

Adult

Body image and weight preoccupation: a comparison between exercising and non-exercising women.

Relationships were examined among certain personality characteristics and variables which assess weight, diet, and appearance concerns for two groups of women--those who were avid exercisers (n = 86) and those who exercised only occasionally or not at all (n = 72). Multiple regression analyses indicated that emotional reactivity (measured by the N scale of the Eysenck Personality Inventory) was strongly related to weight preoccupation (measured by three subscales of the Eating Disorder Inventory) in both groups. Body Mass Index (BMI), but not a measure of subjective body shape, also predicted weight preoccupation for the non-exercisers while the opposite relationship was found for exercisers. In this group, subjective body shape and not BMI influenced weight preoccupation. It was also found that greater body dissatisfaction was related to poorer emotional well-being in the exercise group, and these women reported, to a significantly greater degree than non-exercisers, that their physical appearance was important to their self-esteem. It is possible that an excessive preoccupation with diet and body shape leads some women to take up a vigorous exercise program. However, the absence of differences in weight preoccupation between the groups argues against this. A possibility that has seldom been considered in the literature is that dedication to regular exercise fosters a heightened degree of body narcissism and a distorted impression of one's body size. A focus of attention in an exercise program on the relationship between body size and maximal performance may, in susceptible individuals, increase the likelihood of developing an obsessive attitude toward weight control.

Adult

Spectrum of exercise intolerance in 45 patients with Ebstein's anomaly and observations on exercise tolerance in 11 patients after surgical repair.

To determine the effects of definitive operation for Ebstein's anomaly on rest and exercise cardiorespiratory function, cycle exercise studies were performed on 38 patients with Ebstein's anomaly before definitive operation and on 11 patients after operation. An atrial septal defect was present in 29 of the 38 preoperative patients and in none of the postoperative patients. Seven of the postoperative patients had tricuspid valvuloplasty and four had valve replacement. Exercise tolerance, as defined by maximal oxygen uptake, was significantly greater in patients after operation for Ebstein's anomaly than in the preoperative patients. However, exercise tolerance for preoperative patients without an atrial septal defect was similar to that for postoperative patients. Tricuspid valve repair or replacement appeared to affect favorably cardiac output response to exercise. Rest systemic arterial oxygen saturation increased from 88 to 95% and exercise saturation from 77 to 93% after operation. Rest ventilatory equivalent for oxygen decreased from 48 +/- 13 preoperatively to 37 +/- 6 postoperatively, and exercise ventilatory equivalent for oxygen decreased from 53 +/- 23 preoperatively to 38 +/- 6 postoperatively. Definitive operation (tricuspid valvuloplasty or replacement and atrial septal defect closure) for Ebstein's anomaly results in significant improvement of exercise tolerance, normalization of systemic arterial oxygen saturation and reduction of excess ventilation at rest and during exercise.

Adolescent

The nasal response to exercise and exercise induced bronchoconstriction in normal and asthmatic subjects.

Two studies were carried out to test the hypothesis that the fall and recovery of nasal resistance after exercise in asthmatic and non-asthmatic subjects are related to the development of bronchoconstriction after exercise. In study 1 nasal resistance (posterior rhinomanometry) and specific airway resistance (sRaw) were measured before challenge and one, five, 10 and 30 minutes after four minutes of exhausting legwork exercise in nine asthmatic subjects and nine age matched healthy subjects. One minute after exercise there was a reduction in nasal resistance of 49% (SD 15%) from baseline in the healthy subjects and of 66% (17%) in the asthmatic subjects. This response and the subsequent return of nasal resistance to baseline values did not differ significantly between the two groups despite a substantial difference in the change in sRaw, an increase of 74% (45%) in the asthmatic subjects 10 minutes after exercise, and no change in the non-asthmatic subjects. In study 2, nasal and specific airway resistances were monitored according to the same measurement protocol in six subjects with increased airway reactivity. Subjects exercised on two occasions, wearing a noseclip, once while breathing cold, dry air and once while breathing warm, humid air. The fall in nasal resistance was similar under both conditions (to 47% and 39% of baseline), through sRaw rose only after cold air inhalation (to 172% of baseline). The results indicate that the nasal response to exercise is not related to bronchial obstruction in asthmatic subjects after exercise or to the temperature or humidity of the air inspired through the mouth during exercise.

Adult