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PubMedDate not supplied

Exercise tolerance and blood pressure response to exercise testing in children and adolescents after renal transplantation.

The aim of the study was to assess exercise tolerance and blood pressure (BP) response to treadmill exercise in children after renal transplantation. Forty-five children were selected (29 males and 16 females) whose mean age was 14.3 +/- 4.2 years. All children had Hb >/= 10 g/dl and creatinine clearance >/=40 ml/min/1.73 m2. They were at least 6 months posttransplantation and were on triple immunosuppressive therapy. Twenty-seven were also on various antihypertensive medications. Each underwent clinical examination and measurement of BP, both at rest and during exercise testing on treadmill. The test was stopped on muscular fatigue or exhaustion. The patients were divided into two groups: those off (A) or on (B) antihypertensive therapy. When compared to a population of healthy children the patients had reduced exercise tolerance (10.1 +/- 2.1 vs 15.1 +/- 1.7 min, p < 0.001) (67 +/- 16%), increased heart rate (174 +/- 19 vs 161 +/- 19 beats/min, p < 0.001) (109 +/- 15%), and increased maximum systolic BP (150 +/- 26 vs 134 +/- 13 mmHg, p < 0. 001) (113 +/- 19%) at comparable workloads. Within the two patient groups, significant differences were observed during exercise testing for maximum heart rate, which was lower in group B (p = 0.03), and maximum systolic BP, which was higher in group A (p = 0.04). Our study confirms that children and adolescents on immunosuppressive therapy after renal transplantation have a hypertensive response during exercise, probably related to medication-induced peripheral vascular tone.

Adolescent↗
PubMed1999

Prognostic value of myocardial perfusion imaging in patients with high exercise tolerance.

BACKGROUND: Although high exercise tolerance is associated with an excellent prognosis, the significance of abnormal myocardial perfusion imaging (MPI) in patients with high exercise tolerance has not been established. This study retrospectively compares the utility of MPI and exercise ECG (EECG) in these patients. METHODS AND RESULTS: Of 388 consecutive patients who underwent exercise MPI and reached at least Bruce stage IV, 157 (40.5%) had abnormal results and 231 (59.5%) had normal results. Follow-up was performed at 18+/-2.7 months. Adverse events, including revascularization, myocardial infarction, and cardiac death, occurred in 40 patients. Nineteen patients had revascularization related to the MPI results or the patient's condition at the time of MPI and were not included in further analysis. Seventeen patients (12.2%) with abnormal MPI and 4 (1.7%) with normal MPI had adverse cardiac events (P<0.001). Cox proportional-hazards regression analysis showed that MPI was an excellent predictor of cardiac events (global chi2=13.2; P<0.001; relative risk=8; 95% CI=3 to 23) but EECG had no predictive power (global chi2=0.05; P=0.8; relative risk=1; 95% CI=0.4 to 3.0). The addition of Duke's treadmill score risk categories did not improve the predictive power of EECG (global chi2=0.17). The predictive power of the combination of EECG (including Duke score categories) and MPI was no better than that of MPI alone (global chi2=13.5). CONCLUSIONS: Unlike EECG, MPI is an excellent prognostic indicator for adverse cardiac events in patients with known or suspected CAD and high exercise tolerance.

Adult↗
PubMed1992

Prognostic value of exercise thallium scintigraphy in patients with good exercise tolerance and a normal or abnormal exercise electrocardiogram and suspected or confirmed coronary artery disease.

Exercise thallium scintigraphy is widely used to assess prognosis in patients with suspected or proven coronary artery disease. The incremental prognostic value of this technique in patients who have good exercise tolerance has not been well studied. Two hundred ninety-nine patients with known or suspected coronary artery disease without prior myocardial infarction or revascularization procedure referred for exercise myocardial perfusion imaging and able to exercise to greater than or equal to stage III of the Bruce protocol were included. After a mean follow-up of 50 +/- 10 months, there were 15 cardiac events (5%). The incidence of cardiac events was 10 versus 3% (p less than 0.001) in patients with an abnormal versus normal thallium-201 scan, and 9 versus 3% (p = 0.03) for an abnormal versus normal exercise electrocardiogram. When the 185 patients with a normal exercise electrocardiogram were examined, the incidence of cardiac events was 3% (5 of 150) in patients with a normal scan versus 0% (0 of 35) in patients with an abnormal scan. In the 114 patients with an abnormal exercise electrocardiogram, an abnormal thallium-201 scan was predictive of cardiac events (18% [8 of 44] versus 3% [2 of 70]; p = 0.006). Stepwise logistic regression analysis selected an abnormal thallium-201 scan and abnormal exercise electrocardiogram, low peak exercise heart rate, and male gender as independent variables associated with a significant increased risk of cardiac events. Thus, in patients with known or suspected coronary artery disease and good exercise tolerance, the addition of thallium-201 imaging in patients with an abnormal exercise electrocardiogram provides useful prognostic information.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMed1990

[The relationship between preoperative status and postoperative exercise tolerance after mitral valve replacement].

Treadmill exercise test was performed for the evaluation of exercise tolerance after mitral valve replacement. The duration of maximum exercise tolerance in TR free group had no significant difference as compared with TR combined group. Preoperative RV function in TR combined group was kept relatively good as shown in cardiac index, pulmonary arterial and right atrial pressure. As hemodynamics was improved by TAP (TVR), it may not occur the difference in exercise tolerance between the groups. The duration of maximum exercise tolerance with MS group showed shorter tolerance than that of MR group. This difference in MS group might be considered due to the limitation of LV dilatation by rheumatic cardiac damage. Exercise tolerance after MVR was significantly lowered by atrial fibrillation, cardio-thoracic ratio over 60% and pulmonary vascular resistance over 3.0 Runits.m2.

Exercise Tolerance↗
PubMed1998

A step in the right direction: assessing exercise tolerance in cystic fibrosis.

Exercise tolerance may be reduced in patients with cystic fibrosis, but it is not always possible to predict this from standard lung function measurements. Formal exercise testing may, therefore, be necessary, and the test should be simple and readily available. We have developed a "3-minute step test" and compared it with the standard 6-minute walking test. Subjects stepped up and down a 15-cm-high single step at a rate of 30 steps per minute for 3 minutes. The effect of the step test on spirometry was tested first in 31 children with CF (mean age, 12.0 years), who had a mean (range) baseline forced expired volume in 1 second (FEV1) of 64% (18-94%) of predicted values. The step test was then compared with the standard 6-minute walk in a further 54 patients with cystic fibrosis (mean age, 12.5 years), with mean (range) baseline FEV1 of 61% (14-103%) of predicted values. Outcome measures were minimum arterial oxygen saturation (SaO2), maximum pulse rate, and the modified Borg dyspnea score. Post-step test spirometry showed mean (95% CI) changes of -1.1% (-6.0 + 3.9%) for forced vital capacity, of -1.6% (-4.2 + 1.1%) for FEV1, and +0.25% (-2.8 + 3.3%) for peak expiratory flow, although 5/31 children showed >15% drop in one or more parameters. The step and walk tests both produced significant changes (P < 0.0001) in all outcomes, with a mean (range) minimum SaO2 of 92% (75-98%) versus 92% (75-97%), a maximum pulse rate of 145 b.p.m. (116-189) versus 132 (100-161), and a Borg score of 2.5 (0-9) versus 1.0 (0-5), respectively. Comparison of the two tests showed that the step test increased breathlessness (mean change Borg score, 2.3 vs. 0.8; P < 0.0001) and pulse rate (mean change, 38% vs. 24%, P < 0.0001) significantly more than the walk, whereas the decrease in SaO2 was similar (mean change, -2.9% vs. -2.6%; P = 0.12). Some patients with a significant drop in SaO2 (>4%) would not have the decrease predicted from their baseline lung function. Reproducibility for the two tests was similar. The step test is quick, simple and portable, and is not dependent on patient motivation. Although the step test is more tiring, its effect on SaO2 is similar to the 6-minute walking test. It is a safe test that may prove to be a valuable measure of exercise tolerance in children with pulmonary disease, although longitudinal studies are now needed.

Adolescent↗
PubMed1988

[Cardiac exercise tolerance of infarct patients in exercise therapy].

UNLABELLED: 92 female patients with myocardial infarction were divided into three exercise groups of 25 W, 50 W and 75 W according to their symptom-limited working capacity and examined during bicycle ergometer training. Exercise tolerance, training heart rate and arterial lactic acid were analyzed. RESULTS: 1. Increase in maximal working capacity corresponds to a decrease in limiting cardiac symptoms, or an increase of limiting symptoms, e.g., in tired leg muscles. 2. Intensity of training (as a percentage of maximal symptom-limited work capacity) is 55 +/- 21%, 73 +/- 15%, and 90 +/- 8% for groups of 25, 50 and 75 W (p less than 0.05) respectively. 3. Training heart rate and lactic acid increase significantly proportional to the increase of work capacity. 4. In all three exercise groups, training heart rate corresponds to about 84% maximal heart rate measured at maximal working capacity. 5. Mean maximal lactic acid level is at 3.18 +/- 0.97 mmol/l for the whole exercise group on 75 W. Within this group, only a small subgroup of seven women, who were limited in maximal working capacity by tired leg muscles, reached the so-called anaerobic threshold of 4 mmol/l lactic acid. 6. Female patients greater than or equal to 60 years have partially significant higher mean lactic acid levels for the same exercise load as women less than or equal to 59 years. CONCLUSION: Gender specific differences in performance in women and the cardiac situation in female patients were considered on the basis of symptom-limited performance and body-weight-related physical training, regulated by individual training heart rate.

Angina Pectoris↗
PubMed1997

Role of maximal oxygen consumption in establishment of heart transplant candidacy for heart failure patients with intermediate exercise tolerance.

Maximal exercise oxygen consumption (VO2max) was measured in patients with chronic congestive heart failure undergoing evaluation for heart transplantation. Although VO2max correlated with survival for the group as a whole, it did not demonstrate survival discrimination for patients in the intermediate range (VO2max = 12 to 17 ml/kg/min) and should therefore not be used as a benchmark test for determination of appropriateness for cardiac transplantation in this group of patients.

Adult↗
PubMed1991

[Evaluation of patient-oriented exercise tolerance based on symptoms of patients with heart failure].

Exercise tolerance is one of the most important factors when evaluating patients with heart failure, because it is closely related to their symptoms, Treadmill or ergometer test is usually used to evaluate exercise tolerance. But these tests are painful and sometimes dangerous to the seriously-ill patients. Further exercise tolerance tests reflect the exercise capacity under unusual conditions, which differs greatly from daily activities. So it is very questionable whether we can evaluate actual exercise capacity by exercise tolerance tests. Therefore I devised my own exercise tolerance classification, with 10 Grades according to the symptoms felt during walking. I used this classification for patients with heart failure, and investigated its utility. I studied the correlation between the new classification and the symptom-limited exercise duration in 18 patients, and between the classification and anaerobic threshold in 12 patients. I got good correlation in each of them; (r = 0.842,p less than 0.001) and (r = 0.806, p less than 0.01). The classification also correlated with pulmonary wedge pressure (r = -0.778, p less than 0.05), but it had no correlation with other hemodynamic and morphological parameters. The classification also reflected therapeutic efficacy of heart failure. These results indicate that the new classification is useful in evaluating exercise tolerance without imposing any discomfort on patients with heart failure.

Adolescent↗
PubMed1999

Self-reported exercise tolerance and the risk of serious perioperative complications.

BACKGROUND: Impaired exercise tolerance during formal testing is predictive of perioperative complications. However, for most patients, formal exercise testing is not indicated, and exercise tolerance is assessed by history. OBJECTIVE: To determine the relationship between self-reported exercise tolerance and serious perioperative complications. METHODS: Our study group consisted of 600 consecutive outpatients referred to a medical consultation clinic at a tertiary care medical center for preoperative evaluation before undergoing 612 major noncardiac procedures. Patients were asked to estimate the number of blocks they could walk and flights of stairs they could climb without experiencing symptomatic limitation. Patients who could not walk 4 blocks and climb 2 flights of stairs were considered to have poor exercise tolerance. All patients were evaluated for the development of 26 serious complications that occurred during hospitalization. RESULTS: Patients reporting poor exercise tolerance had more perioperative complications (20.4% vs 10.4%; P<.001). Specifically, they had more myocardial ischemia (P = .02) and more cardiovascular (P = .04) and neurologic (P = .03) events. Poor exercise tolerance predicted risk for serious complications independent of all other patient characteristics, including age (adjusted odds ratio, 1.94; 95% confidence interval, 1.19-3.17). The likelihood of a serious complication occurring was inversely related to the number blocks that could be walked (P = .006) or flights of stairs that could be climbed (P = .01). Other patient characteristics predicting serious complications in multivariable regression analysis included history of congestive heart failure, dementia, Parkinson disease, and smoking greater than or equal to 20 pack-years. CONCLUSION: Self-reported exercise tolerance can be used to predict in-hospital perioperative risk, even when using relatively simple and familiar measures.

Aged↗
PubMed1984

Cardiac abnormalities and exercise tolerance in patients receiving renal replacement therapy.

The exercise tolerance of the survivors of a consecutive group of 100 patients in a renal dialysis and transplant programme was compared with the prevalence of cardiac abnormalities detected by exercise testing, echocardiography, and radionuclide angiography. Fifty four patients attended for investigation 27 (SD 7) months after starting renal replacement therapy. Forty three of them (80%) were receiving antihypertensive treatment. Their performance on a bicycle ergometer exercise test was compared with that of 62 normal subjects and the patients divided into five groups of decreasing ability. The exercise tolerance of the patients was very poor, only 17 performing within the normal range. Impairment in exercise capacity was not explained by the type or quality of renal replacement therapy. Fourteen patients developed ischaemic electrocardiographic changes on exercise. Left ventricular ejection fraction was assessed by gated blood pool scanning in 37 patients; all nine of the patients with an abnormally low radionuclide ejection fraction also had abnormal exercise tolerance. Satisfactory M mode echocardiograms were obtained from 45 of the patients, and only two were normal. Left ventricular hypertrophy was detected in 25 (56%) of the echocardiograms, and abnormalities indicating impaired left ventricular function were common and widespread. Grouping all the abnormal cardiac features together for the patients in each exercise group showed a striking linear trend of increasing proportion of cardiac abnormalities with worsening exercise tolerance among the five exercise groups (p less than 0.001). The proportion of patients becoming unemployed within one year of starting renal replacement therapy similarly increased, from nil to 60% from the best exercise group to the most incapacitated. Twenty nine of the original cohort of 100 patients subsequently died, cardiovascular disease accounting for 12 (41%) of these deaths. Diminished exercise tolerance in patients receiving renal replacement therapy is strongly associated with cardiac abnormalities and reduced employment prospects.

Adolescent↗
PubMed2002

[Atenolol induced bradycardia in patients with stable angina: effects on exercise tolerance, myocardial perfusion and left ventricular contractility].

AIM: To assess effects of atenolol-induced heart rate decrease on myocardial perfusion, left ventricular contractility and tolerance to exercise in patients with chronic coronary artery disease. MATERIAL AND METHODS: Twenty eight men (mean age 54,5-/+9,2 years) with stable class I-III angina and positive reproducible result of bicycle exercise test underwent rest/stress 99mTc-MIIBI gated single-photon emission computed tomography (SPECT) before and after 10 days of administration of atenolol (20 patients) or placebo (8 patients). Dose of atenolol was titrated to achieve at least 15% decrease of heart rate from baseline. RESULTS: After 10 days of treatment with atenolol heart rate decreased from 78-/+3.1 to 59-/+1.1 bpm (p=0.01), whereas in placebo group there were no significant changes. Compared with placebo, treatment with atenolol was associated with significant decreases in extent and severity of perfusion defects, ischemic score and number of ischemic segments. No significant changes of parameters of left ventricular contractility occurred. Treatment with atenolol was associated with symptomatic improvement and increase of the total exercise time. CONCLUSION: Heart rate lowering during monotherapy with atenolol was associated with improvement of myocardial perfusion and tolerance to exercise.

Adrenergic beta-Antagonists↗
PubMed1996

Effect of warming of exercising legs on exercise capacity in patients with impaired exercise tolerance.

OBJECTIVE: The purpose of this study was to determine whether warming of exercising legs improves exercise capacity in patients with cardiac disease and low exercise tolerance. BACKGROUND: Exercising muscle temperature reflects both muscle metabolic rate and muscle blood flow. Increase in muscle temperature in exercising legs is impaired in patients with chronic heart failure. We hypothesized that the mechanisms responsible for impairment of temperature increase in exercising muscle might be related to those responsible for low exercise tolerance. METHODS: We studied 17 patients with cardiac disease whose anaerobic threshold (AT) ranged from 6.6 to 14.8 ml/kg/min (mean 11.2 +/- 1.9 SD). Subjects performed symptom-limited sitting cycle ergometer exercise with or without warming of the thighs. Both thighs were warmed by use of hot packs fixed by supporters. To determine the effect of the supporters themselves on AT and peak VO2, the same ergometer exercise was performed by 7 patients with or without supporters. Peak VO2 and AT were determined by concomitant respiratory gas monitoring. RESULTS: 1) Warming of the thighs increased deep temperature in the thighs (1.0 approximately 2.8 degrees C). 2) AT and peak VO2 were significantly improved in the warming exercise compared with the non-warming exercise (p < 0.01, p < 0.01). 3) There was no significant difference in AT or peak VO2 between the exercise with and without supporters. CONCLUSION: The findings of this study indicate that warming of exercising legs improves exercise capacity in patients with cardiac disease and low exercise tolerance.

Aged↗
PubMed2002

Gender and age differences in plasma carnitine, muscle strength, and exercise tolerance in haemodialysis patients.

BACKGROUND: Haemodialysis patients have impaired exercise tolerance that may be related to impaired carnitine availability and/or alterations in carnitine metabolism. As carnitine metabolism is sex- and age-related, we examined plasma free and esterified carnitine concentrations, muscle strength, and estimated exercise tolerance in female (n=51) and male (n=63) patients of different ages (18-86 years). METHODS: Concentrations of free carnitine and acetylcarnitine were determined in the plasma of patients. Isometric handgrip strength was measured using a dynamometer while exercise tolerance was predicted from scores for self-reported walking distance on the level and on an incline. RESULTS: Plasma total carnitine concentration in the females was significantly lower than that of males (35.4+/-1.3 and 42.4+/-1.4 micro mol/l, respectively, P<0.01). This was almost entirely due to the lower plasma free carnitine concentration of females when compared with the males (20.6+/-0.9 and 26.3+/-1.1 micro mol/l, respectively, P<0.05). Furthermore, plasma free carnitine concentrations were negatively correlated with age in females (r=-0.45, P<0.001) even when the linear effects of haemoglobin, albumin, body weight, time on dialysis, and muscle strength were removed from the regression analysis (partial correlation coefficient; pcc=-0.43, P=0.018), but not in the males (r=0.03, P>0.05). Isometric handgrip strength and estimated exercise tolerance on the level were lower in females than males (138.9+/-10.9 and 259.0+/-15.2 N, P<0.001; and 3.5+/-0.2 and 4.3+/-0.2, P<0.05, respectively). Isometric handgrip strength and estimated exercise tolerance (walking distance on the level and on an incline) were positively correlated with plasma free carnitine concentrations in females, but not in the males. CONCLUSIONS: There was a strong relationship between plasma free carnitine concentrations and age in female patients, but not in males. It is unlikely that the reduction in plasma free carnitine in females was a direct causative factor in their reduced exercise tolerance, but probably reflects greater muscle de-conditioning/atrophy with age in female patients.

Adult↗
PubMed1998

Emotional status does not alter exercise tolerance in patients with chronic obstructive pulmonary disease.

Exercise tolerance in chronic obstructive pulmonary disease (COPD) patients has been shown to be related to airway limitation and dyspnoea, but little is known about the effects of an emotional status on physical performance. We examined 49 COPD patients with a wide spectrum of airway limitation severity and hypoxaemia. Exercise tolerance was evaluated using the Six-minute Walking Distance Test (6MWD), dyspnoea at rest and on exercise was measured using the visual analogue scale, and the emotional status was evaluated using the battery of psychological tests. The average 6MWD (mean+/-SD) was 355+/-112 m. In the majority of patients a fall in arterial blood oxygen saturation (Sa,O2) on exercise of >3% was found. The mean dyspnoea score of 21+/-19 at rest increased to 66+/-19 on exercise. All subjects demonstrated an increased level of anxiety. The majority also demonstrated elevated emotional tension, and half of the study group showed signs of depression. Step-wise multiple regression analysis with results of 6MWD as dependent and other studied variables as independent variables showed that exercise tolerance depended mainly on airway limitation. The forced expiratory volume in one second (FEV1) explained 24% of the variance. The forced vital capacity added a further 10%, and arterial blood carbon dioxide tension contributed 7%. The dyspnoea level on exercise added only 0.9%. All four variables explained 42% of the variance. There was no correlation between 6MWD and any of the variables characterizing the emotional status. We conclude that the emotional status of chronic obstructive pulmonary disease patients is characterized by an increased level of psychological tension, anxiety and depression, but these do not affect exercise tolerance as assessed by the six-minute walking distance test.

Anxiety↗
PubMed1999

Losartan improves exercise tolerance in patients with diastolic dysfunction and a hypertensive response to exercise.

OBJECTIVES: The aim of the study was to test the hypothesis that angiotensin II (Ang II) blockade would improve exercise tolerance in patients with diastolic dysfunction and a marked increase in systolic blood pressure (SBP) during exercise. BACKGROUND: Diastolic dysfunction may be exacerbated during exercise, especially if there is a marked increase in SBP. Angiotensin II may contribute to the hypertensive response to exercise and impair diastolic performance. METHODS: We performed a randomized, double-blind, placebo-controlled, crossover study of two weeks of losartan (50 mg q.d.) on exercise tolerance and quality of life. The subjects were 20 patients, mean age 64 +/- 10 years with normal left ventricular systolic function (EF >50%), no ischemia on stress echocardiogram, mitral flow velocity E/A <1, normal resting SBP (<150 mm Hg), and a hypertensive response to exercise (SBP >200 mm Hg). Exercise echocardiograms (Modified Bruce Protocol) and the Minnesota Living With Heart Failure questionnaire were administered at baseline, and after each two-week treatment period, separated by a two-week washout period. RESULTS: Resting blood pressure (BP) was unaltered by placebo or losartan. During control, patients were able to exercise for 11.3 +/- 2.5 (mean +/- SD) min, with a peak exercise SBP of 226 +/- 24 mm Hg. After two weeks of losartan, baseline BP was unaltered, but peak SBP during exercise decreased to 193 +/- 27 mm Hg (p < 0.05 vs. baseline and placebo), and exercise time increased to 12.3 +/- 2.6 min (p < 0.05 vs. baseline and placebo). With placebo, there was no improvement in exercise duration (11.0 +/- 2.0 min) or peak exercise SBP (217 +/- 26 mm Hg). Quality of life improved with losartan (18 +/- 22, p < 0.05) compared to placebo (22 +/- 26). CONCLUSIONS: In patients with Doppler evidence of diastolic dysfunction at rest and a hypertensive response to exercise, Ang II receptor blockade blunts the hypertensive response to exercise, increases exercise tolerance and improves quality of life.

Adult↗
PubMedDate not supplied

The effects of a pulmonary rehabilitation program on pulmonary function tests and exercise tolerance in patients with Parkinson's disease.

The effects of exercise training, as a part of a pulmonary rehabilitation program, on pulmonary function tests and exercise tolerance have not been clarified in patients with Parkinson's disease (PD). This study compares the results of pulmonary function test parameters and exercise tolerance in individuals with and without PD. It also compares the results of pulmonary function test parameters, exercise tolerance and subjective ratings of perceived exertion (RPE) between entry to and the end of exercise training program in patients with PD. Nine patients with PD and 9 age-matched healthy controls participated in the study. Pulmonary function tests and a six-minute walk test were performed in subjects with and without PD, and the Borg RPE scale was applied to patients with PD at the beginning of the study. After the exercise training program, all parameters were recorded again in patients with PD. Statistically significant differences were observed between the groups in some of the pulmonary function test parameters and in exercise tolerance. After the training program, we observed improvement in some of the pulmonary function test parameters, exercise tolerance, and RPE in patients with PD.

Adult↗
PubMed2000

[Acute effects of oxygen on dyspnea and exercise tolerance in patients with pulmonary emphysema with only mild exercise-induced oxyhemoglobin desaturation].

The effects of oxygen on dyspnea and exercise tolerance during a 6-mimute walk test were examined in 10 patients with chronic pulmonary emphysema (CPE) who had only mild hypoxemia at rest (PaO2 > 60 Torr) and mild exercise-induced oxyhemoglobin desaturation (lowest SpO2 > 88%) on compressed air. As a whole, oxygen supplementation (2 l/min) resulted in a 7% increase in the distance walked in 6 min (6 MD), a 3% increase in the lowest SpO2, and an 8% decrease in the dyspnea score. In 6 of 7 patients with severe airflow limitation (one-second forced expiratory volume (FEV1) < 40% of predicted value), 6 MD (7-15%) increased significantly on oxygen, an improvement that correlated significantly with FEV1 (r = -0.65, p < 0.05). These results suggest that supplementary oxygen improves dyspnea and exercise tolerance in CPE patients with only mild exercise-induced hypoxemia despite severe airflow limitation. The long-term efficacy of oxygen in such patients needs further study.

Aged↗
PubMed2001

[Exercise tolerance tests in athletes, then what?].

Exercise tolerance tests in athletes are usually performed to evaluate aerobic exertion capacity and to plan training. They are based on simultaneous measurement of expired gases (determination of ventilation threshold and of VO2max). They can also be used to seek a possible cardiovascular anomaly, particularly in case of clinical symptoms or anomalies on auscultation; findings based on electrocardiography (rhythm, repolarisation, etc.) and on blood pressure readings, however, can lead to suspicion of an early anomaly and direct complementary investigation.

Blood Gas Analysis↗