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Peak Oxygen Uptake (peak + oxygen_uptake)
Selected AbstractsLifestyle, participation, and health-related quality of life in adolescents and young adults with myelomeningoceleDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 11 2009LAURIEN M BUFFART PHD This study aimed to describe participation and health-related quality of life (HRQoL) in adolescents and young adults with myelomeningocele and to explore their relationships with lifestyle-related factors. Fifty-one individuals with a mean age of 21 years 1 month (SD 4y 6mo) years participated (26 males, 25 females; 82% hydrocephalus, 55% wheelchair-dependent). Participation was assessed using the Life Habits Questionnaire, and HRQoL was assessed using the Medical Outcomes Study 36-item Short-form Health Survey. Physical activity was measured using an accelerometry-based activity monitor, fitness (peak oxygen uptake) was measured during a maximal exercise test, and the sum of four skin-folds was assessed to indicate body fat. Relationships were studied using logistic regression analyses. Of the participants, 63% had difficulties in daily activities and 59% in social roles. Participants perceived lower physical HRQoL than a Dutch reference population. Participants with higher levels of physical activity and fitness had fewer difficulties in participating in daily activities (odds ratio [OR]=8.8, p=0.02 and OR=29.7, p=0.02 respectively) and a higher physical HRQoL (OR=4.8, p=0.02 and OR=30.2, p=0.006 respectively), but not mental HRQoL. Body fat was not related to participation or HRQoL. In conclusion, a large proportion of individuals with myelomeningocele had difficulties in participation and perceived low physical HRQoL. Higher levels of physical activity and fitness were related to fewer difficulties in participation and higher physical HRQoL. [source] Endothelial markers in chronic heart failure: training normalizes exercise-induced vWF releaseEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 9 2004L. W. E. Sabelis Abstract Background, Chronic heart failure (CHF) is characterized by endothelial dysfunction. Vascular endothelium is important for control of haemostasis and vasoregulation. The aim of the present study was to investigate plasma levels of several endothelial markers and the exercise-induced changes on these plasma levels in CHF patients. Subsequently, the effect of a 6-month training programme on these markers is described. Materials and methods, Twenty-nine male CHF patients (NYHA II/III, age 60 ± 8 year, body mass index 26·7 ± 2·3 kg m,2, left ventricular ejection fraction 26·3,7·2%; mean ± SD) participated. Patients were randomly assigned to a training or control group. Training (26 weeks; combined strength and endurance exercises) was four sessions/week: two sessions supervised and two sessions at home. Before and after intervention, anthropometry, endothelial markers (haemostasis and vasoregulation), maximal workload and peak oxygen uptake were assessed. Results, Physical training positively affected maximal workload. Plasma levels of endothelial markers were not affected by physical training and not related to exercise tolerance. After training, stimulated (maximal exercise) plasma von Willebrand Factor (vWF) release was present, whereas at baseline this release was absent. Conclusion, Physical training led to normalization of the stimulated plasma vWF release. Plasma levels of other endothelial markers were not affected by physical training either at rest or under stimulated (maximal exercise) conditions. [source] Promising outcomes of an adolescent chronic fatigue syndrome inpatient programmeJOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 5 2009Brett Gordon Introduction: Chronic fatigue syndrome (CFS) is a condition of prolonged and disabling fatigue, which is accompanied by characteristic constitutional and neuropsychiatric symptoms. In children and adolescents, this condition occurring at a developmentally vulnerable time adds to the disability affecting self-concept, autonomy, body image, socialisation, sexuality and academic problems. This case series looks at the effects of a graded exercise programme on physical outcomes, fatigue and mental state in an adolescent population. Methods: Data sets from 16 adolescents who completed combined exercise training as part of the 4-week inpatient intensive CFS programme at the Austin Hospital, Melbourne were analysed. All patients completed an exercise assessment and three questionnaires before beginning any training. A paediatrician (LL) confirmed the diagnosis according to the Fukuda criteria in all patients. Exercise was carefully supervised and prescribed daily by an exercise physiologist (BG) according to each individual's ability and response with the basic aim of increasing exercise tolerance and improving muscle strength and endurance. Results: There was an 18% improvement in volitional time to fatigue (P= 0.02) and 17% improvement in peak oxygen uptake (VO2peak) (P= 0.01). Upper body strength and function improved with a remarkable 70% increase in the number of push-ups. Fatigue severity was reported to improve by 13% (P= 0.01) and depression index improved significantly by 42% (P= 0.02). Conclusions: The significance of these improvements cannot be underestimated as an improvement in physical capacity through increased time to fatigue and less severe fatigue allows adolescents to resume school, social and family activities. [source] Does an Energy Drink Modify the Effects of Alcohol in a Maximal Effort Test?ALCOHOLISM, Issue 9 2004Sionaldo Eduardo Ferreira Background: There are popular reports on the combined use of alcohol and energy drinks (such as Red Bull® and similar beverages, which contain caffeine, taurine, carbohydrates, etc.) to reduce the depressant effects of alcohol on central nervous system, but no controlled studies have been performed. The main purpose of this study was to verify the effects of alcohol, and alcohol combined with energy drink, on the performance of volunteers in a maximal effort test (cycle ergometer) and also on physiological indicators (oxygen uptake, ventilatory threshold, respiratory exchange rate, heart rate, and blood pressure), biochemical variables (glucose, lactate, insulin, cortisol, ACTH, dopamine, noradrenaline, and adrenaline), and blood alcohol levels. Methods: Fourteen healthy subjects completed a double-blind protocol made up of four sessions: control (water), alcohol (1.0 g/kg), energy drink (3.57 ml/kg Red Bull®), and alcohol + energy drink, each 1 week apart. The effort test began 60 min after drug or control ingestion, and the dependent variables were measured until 60 min after the test. Results: Heart rate at the ventilatory threshold was higher in the alcohol and alcohol + energy drink sessions in comparison with control and energy drink sessions. Although in comparison to the control session, the peak oxygen uptake was 5.0% smaller after alcohol ingestion, 1.4% smaller after energy drink, and 2.7% smaller after the combined ingestion, no significant differences were detected. Lactate levels (30 min after drug ingestion, 30 and 60 min after the effort test) and noradrenaline levels (30 min after the effort test) were higher in the alcohol and alcohol + energy drink sessions compared with the control session. Conclusions: The performance in the maximal effort test observed after alcohol + energy drink ingestion was similar to that observed after alcohol only. No significant differences between alcohol and alcohol + energy drink were detected in the physiological and biochemical parameters analyzed. Our findings suggest that energy drinks, at least in the tested doses, did not improve performance or reduce alterations induced by acute alcohol ingestion. [source] Relationship of resting hemoglobin concentration to peak oxygen uptake in heart failure patients,AMERICAN JOURNAL OF HEMATOLOGY, Issue 6 2010Piergiuseppe Agostoni Anemia is frequent in chronic heart failure (HF). To calculate what change in peak oxygen uptake ( O2) should be expected in the event of changes in hemoglobin concentration, we studied the correlation between peak O2 and hemoglobin concentration in a large HF population. We carried out retrospective analysis of all cardiopulmonary exercise tests (CPET) performed in our HF Clinic between June 2001 and March 2009 in HF patients who had a resting hemoglobin concentration measurement taken within 7 days of the CPET. We collected 967 CPETs, 704 tests were considered maximal and analyzed. We identified 181 patients (26%) as anemic. Peak O2 was lower (P < 0.001) in anemic patients (971 ± 23 ml/min) compared with nonanemic (1243 ± 18 ml/min). The slope of the O2 vs. hemoglobin ratio was 109 ml/min/g/dl at peak exercise. This correlation remained significant also when several confounding variables were analyzed by multivariate analysis. As an average, each gram of hemoglobin accounts, at peak exercise, for 109 ml/min change in O2 which is equivalent to 0.97 ml/min/kg. Therefore, in HF patients anemia treatment should increase O2 by 109 ml/min for each g/dl of hemoglobin increase. Am. J. Hematol. 2010. © 2010 Wiley-Liss, Inc. [source] A comparison of physiological variables in aged and young women during and following submaximal exerciseAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 6 2009Michael R. Deschenes Previously, we have examined how aging affects the physiological responses of men to endurance exercise. In the present investigation, we aimed to extend our assessment of the influence of aging on exercise-induced responses by focusing on women. Ten young (20.3 ± 0.3 years; mean ± SE) and 10 aged (75.5 ± 1.2 years) women performed 30 min of cycling at 60,65% of their predetermined peak oxygen uptake. Data for respiratory exchange ratio (RER), heart rate, blood pressure, rectal temperature, and plasma metabolites were collected before exercise, at the 15th and 30th min of exercise, and at 5 and 15 min postexercise. A two-way, repeated measures ANOVA with main effects of age and time was conducted on each variable. Our findings showed that age affected exercise-induced responses of each variable quantified. Although RER, heart rate, temperature, and lactate were significantly (P < 0.05) higher among young women, blood pressure and glucose values were greater among aged women. Moreover, unlike previous results noted among men where age-related differences primarily occurred during postexercise recovery, in women the effect of aging was detected during exercise itself. The data presented here indicate that aging impacts physiological responses of women to prolonged endurance exercise even when relative intensity (% of peak oxygen uptake) is held constant. Combined with our earlier study on men, these findings suggest that gender interacts with aging to determine whether age-related differences are manifested during exercise itself, or during postexercise recovery. Am. J. Hum. Biol., 2009. © 2009 Wiley-Liss, Inc. [source] The effect of antecedent fatiguing activity on the relationship between perceived exertion and physiological activity during a constant load exercise taskPSYCHOPHYSIOLOGY, Issue 5 2007Roger Eston Abstract This study assessed the relationship between the rate of change of the rating of perceived exertion (RPE), physiological activity, and time to volitional exhaustion. After completing a graded exercise test, 10 participants cycled at a constant load equating to 75% of peak oxygen uptake (V, O2peak) to exhaustion. Participants performed two further constant load exercise tests at 75%V, O2peak in a fresh state condition within the next 7 days. The RPE was regressed against time and percentage of the time (%time) to volitional exhaustion in both conditions. Despite a lower respiratory exchange ratio (RER) and higher heart rate at the start of the exercise bout in the fatigued condition, there were no differences in RPE at the onset or completion of exercise. As expected, the rate of increase in RPE was greater in the fatigued condition, but there were no differences when expressed against %time. Results suggest that RPE is set at the start of exercise using a scalar internal timing mechanism, which regulates RPE by altering the gain of the relationship with physiological parameters such as heart rate and RER when these are altered by previous fatiguing exercise. [source] Physical training and testing in patients with chronic obstructive pulmonary diseaseTHE CLINICAL RESPIRATORY JOURNAL, Issue 1 2007Ragnheiður Harpa Arnardóttir Abstract Introduction:, The effects of different training modes need to be investigated further in patients with chronic obstructive pulmonary disease (COPD). Both advanced laboratory tests and field tests are used in patients with COPD to evaluate effects of interventions such as pulmonary rehabilitation. Aims:, The overall aims of the studies were to investigate the effects of different training modalities on exercise capacity and on health-related quality of life (HRQoL) in patients with moderate or severe COPD and, further, to explore two of the physical field tests used in pulmonary rehabilitation, the 12-min walk test and the incremental shuttle walking test (ISWT). Materials and Methods:, Patients with moderate or severe COPD were included. In study I (n = 57), the 12-min walk test was performed three times within 1 week. Exercise-induced hypoxemia (EIH) was assessed by pulse oximeter and was defined as SpO2 < 90%. In study II (n = 93), performance on ISWT was compared to performance on two different cycle tests. In study III (n = 42), the effects of two different combination training programmes were compared when training twice a week for 8 weeks. One programme was mainly based on endurance training (group A), and the other was based on resistance training and on callisthenics (group B). In study IV (n = 60), endurance training with interval resistance was compared to endurance training with continuous resistance. Results:, In study I, the 12-min walking distance (12MWD) did not increase on retesting in patients with EIH, but increased significantly on retesting in the non-EIH patients. In study II, the ISWT was as good a predictor of peak exercise capacity (W peak) as peak oxygen uptake (VO2 peak) was. In study III, W peak and 12MWD increased in group A but not in group B. HRQoL, anxiety and depression were unchanged in both groups. Ratings of perceived exertion at rest were significantly lower in group A than in group B after training and during 12 months of follow-up. Twelve months post training, 12MWD was back to baseline in group A, but was significantly shorter than at baseline in group B. Patients with moderate and severe COPD responded to training in the same way. In study IV, both interval and continuous endurance training increased W peak, VO2 peak, peak exhaled carbon dioxide (VCO2 peak) and 12MWD. Likewise, HRQoL, dyspnoea during activities of daily life, anxiety and depression improved similarly in both groups. At a fixed, sub-maximal workload (isotime), the interval training reduced oxygen cost and ventilatory demand significantly more than the continuous training did. Conclusions:, EIH affects the retest effects on 12MWD. W peak can be predicted from an ISWT similarly well as from VO2 peak. A short training programme can improve W peak and 12MWD when based mainly on endurance training. Both patients with moderate and severe COPD respond to training in the same way. A short endurance training intervention can possibly delay decline in 12MWD for 1 year. Both interval and continuous endurance training improves physical performance and HRQoL. Interval training lowers the energy cost of sub-maximal work more than continuous training does. [source] Physical performance limitations among adult survivors of childhood brain tumorsCANCER, Issue 12 2010Kirsten K. Ness PhD Abstract BACKGROUND: Young adult survivors of childhood brain tumors (BTs) may have late effects that compromise physical performance and everyday task participation. The objective of this study was to evaluate muscle strength, fitness, physical performance, and task participation among adult survivors of childhood BTs. METHODS: In-home evaluations and interviews were conducted for 156 participants (54% men). Results on measures of muscle strength, fitness, physical performance, and participation were compared between BT survivors and members of a population-based comparison group by using chi-square statistics and 2-sample t tests. Associations between late effects and physical performance and between physical performance and participation were evaluated in regression models. RESULTS: The median age of BT survivors was 22 years (range, 18-58 years) at the time of the current evaluation, and they had survived for a median of 14.7 years (range, 6.5-45.9 years) postdiagnosis. Survivors had lower estimates of grip strength (women, 24.7 ± 9.2 kg vs 31.5 ± 5.8 kg; men, 39.0 ± 12.2 kg vs 53.0 ± 10.1 kg), knee extension strength (women, 246.6 ± 95.5 Newtons [N] vs 331.5 ± 5.8 N; men, 304.7 ± 116.4 N vs 466.6 ± 92.1 N), and peak oxygen uptake (women, 25.1 ± 8.8 mL/kg per minute vs 31.3 ± 5.1 mL/kg per minute; men, 24.6 ± 9.5 mL/kg per minute vs 33.2 ± 3.4 mL/kg per minute) than members of the population-based comparison group. Physical performance was lower among survivors and was associated with not living independently (odds ratio [OR], 5.0; 95% confidence interval [CI], 2.0-12.2) and not attending college (OR, 2.3; 95% CI 1.2-4.4). CONCLUSIONS: Muscle strength and fitness values among BT survivors were similar to those among individuals aged ,60 years and were associated with physical performance limitations. Physical performance limitations were associated with poor outcomes in home and school environments. The current data indicated an opportunity for interventions targeted at improving long-term physical function in this survivor population. Cancer 2010. © 2010 American Cancer Society. [source] Antioxidant enzyme activities and DNA damage in children with type 1 diabetes mellitus after 12 weeks of exerciseACTA PAEDIATRICA, Issue 8 2010J Woo Abstract Objective:, The objectives of this study are to assess the effects of a low-intensity exercise training which is not risky for children with type 1 diabetes mellitus (T1DM) on the antioxidant enzyme activities and oxidative stresses compared with healthy controls. Patients and methods:, We studied 10 boys with T1DM (11.21 ± 0.97 age) and 10 age-matched healthy controls (11.90 ± 1.85 age) during the 12 weeks of moderate intensity aerobic exercise. Measurements included peak oxygen uptake, body composition, blood lipid profiles, glycated haemoglobin (HbA1c), oxidized low density lipoprotein (ox-LDL), 8-hydroxy-2,-deoxyguanosine, superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities. Results:, In T1DM patients, the baseline diastolic blood pressure and HbA1c were higher than that in controls (p < 0.05), while the GPx level was lower. The training-induced DNA damage peak was higher in T1DM patients than in controls (p < 0.05), and exercise improved both SOD and GPx levels. Conclusion:, Although our exercise programme increase antioxidant enzyme activities, the results of the study demonstrate that low-intensity aerobic exercise training programme performed over 12 weeks may accelerate adverse effects of antioxidant defence capacity in children with T1DM. Therefore, the future studies should be performed to clarify much more the relationship to exercise and antioxidant capacity in children with T1DM. [source] Increased plasma N-terminal pro-B-type natriuretic peptide and markers of inflammation related to atherosclerosis in patients with primary hyperparathyroidismCLINICAL ENDOCRINOLOGY, Issue 5 2005Christina Gerlach Øgard Summary Objective, Increased risk of cardiovascular disease has been reported in patients with primary hyperparathyroidism (PHPT). The aim of this study was to evaluate novel plasma risk markers of cardiovascular disease in patients with PHPT. Design, PHPT patients were evaluated with a control group. Patients who underwent parathyroidectomy were re-evaluated after 7 and 18 months. Patients, Forty-five PHPT patients and 40 matched controls participated. Seventeen patients underwent parathyroidectomy. Measurements, Plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP), high-sensitivity C-reactive protein (CRP), interleukin-6 (IL-6) and tumour necrosis factor alpha (TNF-,), lipids and blood pressure were measured. In 27 patients a bicycle exercise test and radionuclide angiography were performed, and repeated in those who underwent parathyroidectomy. Results, Plasma NT-proBNP, CRP and TNF-,, but not IL-6, were higher in patients with PHPT than in controls (P < 0·01 and P = 0·17, respectively). In patients with PHPT, NT-proBNP correlated with systolic blood pressure, left ventricular end-diastolic volume, and peak oxygen uptake (all P < 0·01). Log CRP correlated with systolic and diastolic blood pressure (both P < 0·05) and log IL-6 (P < 0·01). No significant correlations were observed between PTH or calcium and risk markers of cardiovascular disease. No decrease in NT-proBNP, markers of inflammation or blood pressure was observed after parathyroidectomy. Conclusions, Our data suggest that hypertension or other factors, rather than plasma calcium or PTH, could explain the increased levels of the inflammatory markers and NT-proBNP in PHPT. We therefore suggest that aggressive treatment of hypertension should be initiated in patients with PHPT to try to reduce the increased cardiovascular mortality described in PHPT. Further prospective studies are needed to validate the suggestion that increased levels of NT-proBNP and inflammatory markers also represent strong prognostic markers of cardiovascular disease in patients with PHPT. [source] Scaling of lactate threshold by peak oxygen uptake and by fat-free mass0·67CLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 3 2007James A. Davis Summary The lactate threshold (LT) represents the onset of metabolic acidosis during cardiopulmonary exercise testing (CPET). It is measured as a O2 in the units of ml min,1. In order to make comparisons among subjects, LT is often scaled or normalized by O2 peak resulting in the LT/O2 peak ratio. Ratio variables have underlying assumptions. One assumption is that the relationship between the numerator and denominator is linear with a zero y -intercept. If the relationship has a positive y -intercept, then the ratio will decrease with increasing values of the scaling variable thereby penalizing subjects with larger values of the scaling variable. Our purpose was to examine the validity of scaling LT by O2 peak and by fat-free mass raised to 0·67 power (FFM0·67) as dimensional analysis predicts that LT is proportional to FFM0·67. Cycle ergometer CPET was administered to 204 healthy, sedentary subjects (103 males) to the limit of tolerance. Lactate threshold was estimated noninvasively using the V-slope technique. Fat-free mass was assessed by skinfolds. The relationship of LT versus O2 peak was linear with a positive y -intercept for both sexes. Consequently, the LT/O2 peak ratio decreased as O2 peak increased for both sexes. The relationship of LT versus FFM0·67was linear with a zero y -intercept for both sexes. Consequently, the plot of the LT/FFM0·67 ratio versus FFM resulted in a straight line with a slope of zero for both sexes. The results of this study support the conclusion that FFM0·67, but not O2 peak, is a valid scaling variable for LT. [source] | ||||||||||