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Exercise Limitation (exercise + limitation)

Distribution by Scientific Domains

Medical Sciences	75%

Selected Abstracts

Impaired oxygen kinetics in beta-thalassaemia major patients

ACTA PHYSIOLOGICA, Issue 3 2009
I. Vasileiadis
Abstract Aim:, Beta-thalassaemia major (TM) affects oxygen flow and utilization and reduces patients' exercise capacity. The aim of this study was to assess phase I and phase II oxygen kinetics during submaximal exercise test in thalassaemics and make possible considerations about the pathophysiology of the energy-producing mechanisms and their expected exercise limitation. Methods:, Twelve TM patients with no clinical evidence of cardiac or respiratory disease and 10 healthy subjects performed incremental, symptom-limited cardiopulmonary exercise testing (CPET) and submaximal, constant workload CPET. Oxygen uptake (Vo2), carbon dioxide output and ventilation were measured breath-by-breath. Results:, Peak Vo2 was reduced in TM patients (22.3 ± 7.4 vs. 28.8 ± 4.8 mL kg,1 min,1, P < 0.05) as was anaerobic threshold (13.1 ± 2.7 vs. 17.4 ± 2.6 mL kg,1 min,1, P = 0.002). There was no difference in oxygen cost of work at peak exercise (11.7 ± 1.9 vs. 12.6 ± 1.9 mL min,1 W,1 for patients and controls respectively, P = ns). Phase I duration was similar in TM patients and controls (24.6 ± 7.3 vs. 23.3 ± 6.6 s respectively, P = ns) whereas phase II time constant in patients was significantly prolonged (42.8 ± 12.0 vs. 32.0 ± 9.8 s, P < 0.05). Conclusion:, TM patients present prolonged phase II on-transient oxygen kinetics during submaximal, constant workload exercise, compared with healthy controls, possibly suggesting a slower rate of high energy phosphate production and utilization and reduced oxidative capacity of myocytes; the latter could also account for their significantly limited exercise tolerance. [source]

Are Hormonal Responses to Exercise in Young Men with Down's Syndrome Related to Reduced Endurance Performance?

JOURNAL OF NEUROENDOCRINOLOGY, Issue 5 2008
V-A. Bricout
The aim of the present study was to analyse whether hormonal responses could explain an exercise limitation in Down's syndrome (DS). Fourteen young men with DS (mean age 22.5 ± 0.7 years) and 15 controls (CONT, mean age 22.5 ± 0.3 years) participated in the study. During a treadmill submaximal incremental test, blood samples were collected for determination of hormonal and metabolic variables. Compared to CONT, DS individuals showed lower VO2max (P < 0.05), and lower duration of submaximal incremental exercise (P < 0.001). At rest, DS individuals showed greater catecholamines, insulin and leptin values (P < 0.05), but lower testosteronemia and cortisolemia (P < 0.05), compared to CONT. During submaximal incremental tests, catecholamines and cortisol were not increased, whereas the insulin concentration of DS individuals was significantly higher (P < 0.01) compared to CONT. Glycaemia increased significantly at the end of submaximal incremental test for CONT but not for DS individuals (P < 0.01). Maximal fat oxidation was lower (P < 0.01), whereas non-esterified fatty acids concentrations rose significantly during submaximal exercise in DS individuals. These results indicate an altered hormonal response to exercise in DS individuals. This endocrine profile at rest and during exercise may limit endurance performance in DS individuals. [source]

Design and validation of an interpretative strategy for cardiopulmonary exercise tests

RESPIROLOGY, Issue 6 2007
Andreas SCHMID
Background and objective: Cardiopulmonary exercise testing (CPET) is a common investigation for the evaluation of exertional dyspnoea. At present, there is no consensus on the best interpretative strategy and none of the available algorithms have been validated. The aim of this study was to develop and validate a standardized strategy for the interpretation of CPET. Methods: This study analysed 199 CPETs from patients with exertional dyspnoea. Using a set of 100 CPETs a standardized interpretation using a four-step approach was developed that scored: examination quality, performance, exercise limitation and cofactors. A second set of 99 CPETs was interpreted by two experts in the field, initially independently and then in a consensus conference. The standardized interpretation was compared with each expert, the expert's consensus and the original clinical reports. Results: Matching between the standardized interpretation strategy and the expert consensus was 82%, 82% with one expert and 86% with a second expert and 64% with the original clinical reports. From one to four exercise-relevant cofactors were found in 77% of the patients. Conclusion: The standardized interpretation showed a precision comparable to the opinion of a single expert and significantly improved the consistency in CPET reports in a pulmonary centre with different physicians and varying degrees of expertise. [source]

Fitness testing of pediatric liver transplant recipients

LIVER TRANSPLANTATION, Issue 3 2001
Viswanath B. Unnithan PhD
Liver transplantation is accepted as the standard management for end-stage liver disease in children. Pediatric heart and heart-lung transplant recipients have shown significantly diminished exercise capacities compared with age-matched, able-bodied, control subjects. The primary aim of this study is to compare the fitness levels of a group of pediatric liver transplant (LT) recipients (LT group, 20 boys, 9 girls; age, 8.9 ± 4.8 years; 56 ± 35 months posttransplantation) with a group of able-bodied control subjects (22 boys, 12 girls; age, 8.4 ± 3.8 years). The secondary aim is to compare the performance of the LT group against the Fitnessgram criterion standards. We assessed muscular endurance by means of a partial curl-up, flexibility by means of the back-saver sit and reach, and cardiorespiratory fitness by means of the progressive aerobic cardiovascular endurance run (PACER). The only significant (P < .05) difference between the 2 groups was the number of shuttles run in the PACER (control, 16.8 ± 9.8 v LT, 11.5 ± 8.4 shuttles). Other differences between the 2 groups were not significant. With regard to satisfying the Fitnessgram criterion standards, only 35% of the LT group achieved the standards for the partial curl-up, 88% of the LT group achieved the criterion standards for flexibility, and 0% achieved the standards for the PACER. These results indicate that the LT group has diminished exercise capacity. The origins of exercise limitations deserve further investigation. [source]