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VO2 Peak (vo2 + peak)
Selected AbstractsThe effects of maximal treadmill graded exercise testing on haemorheological, haemodynamic and flow cytometry platelet markers in patients with systolic or diastolic heart failureEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 3 2008I. Chung ABSTRACT Background, Acute exercise has been associated with activation of thrombosis, and this risk may be accentuated in patients with heart failure. Given the relation of platelets to atherothrombosis, we tested the hypothesis that acute exercise would adversely affect platelet indices and platelet activation markers in patients with systolic and diastolic heart failure. Materials and methods, We studied 20 patients with systolic heart failure (17 men, 3 women; mean age 64 ± 10 years, all with ejection fraction (EF) , 40%) and 20 patients with diastolic heart failure (14 men, 6 women; mean age 64 ± 8 years, mean EF = 66%) who were exercised to maximal intensity, who were compared to 13 healthy controls (6 men, 7 women; mean age 60 ± 4 years, mean EF = 73%). We measured platelet indices (platelet volume, mass and component) and platelet activation markers (platelet-bound CD62P%G, CD63%G and CD40L%G using flow cytometry, as well as plasma sCD40L and soluble P-selectin (sP-sel) levels). Results, Baseline Mean Platelet Volume (MPV), sP-sel, CD40L%G and CD63%G levels were significantly higher in patients with systolic and diastolic heart failure, when compared with controls. The mean exercise duration and VO2 peak in patients with systolic and diastolic heart failure were not significantly different, but lower than that seen in healthy controls. Following exercise, mean haematocrit, CD62P%G, and CD63%G significantly increased in all three subject groups (all P < 0·05). The proportional change in CD62P%G and CD63%G were not significantly different between healthy controls and heart failure patients (P > 0·05). Conclusion, Acute maximal graded exercise increases platelet activation markers, with no disproportionate differences between heart failure patients and healthy controls, despite the former group having a lower exercise tolerance and VO2 peak. [source] Endurance Exercise Training in Older Patients with Heart Failure: Results from a Randomized, Controlled, Single-Blind TrialJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 11 2009Peter H. Brubaker PhD OBJECTIVES: To test the hypothesis that exercise training (ET) improves exercise capacity and other clinical outcomes in older persons with heart failure with reduced ejection fraction (HfrEF). DESIGN: Randomized, controlled, single-blind trial. SETTING: Outpatient cardiac rehabilitation program. PARTICIPANTS: Fifty-nine patients aged 60 and older with HFrEF recruited from hospital records and referring physicians were randomly assigned to a 16-week supervised ET program (n=30) or an attention-control, nonexercise, usual care control group (n=29). INTERVENTION: Sixteen-week supervised ET program of endurance exercise (walking and stationary cycling) three times per week for 30 to 40 minutes at moderate intensity regulated according to heart rate and perceived exertion. MEASUREMENTS: Individuals blinded to group assignment assessed four domains pivotal to HFrEF pathophysiology: exercise performance, left ventricular (LV) function, neuroendocrine activation, and health-related quality of life (QOL). RESULTS: At follow-up, the ET group had significantly greater exercise time and workload than the control group, but there were no significant differences between the groups for the primary outcomes: peak exercise oxygen consumption (VO2 peak), ventilatory anaerobic threshold (VAT), 6-minute walk distance, QOL, LV volumes, EF, or diastolic filling. Other than serum aldosterone, there were no significant differences after ET in other neuroendocrine measurements. Despite a lack of a group "training" effect, a subset (26%) of individuals increased VO2 peak by 10% or more and improved other clinical variables as well. CONCLUSION: In older patients with HFrEF, ET failed to produce consistent benefits in any of the four pivotal domains of HF that were examined, although the heterogeneous response of older patients with HFrEF to ET requires further investigation to better determine which patients with HFrEF will respond favorably to ET. [source] Physical training and testing in patients with chronic obstructive pulmonary diseaseTHE CLINICAL RESPIRATORY JOURNAL, Issue 1 2007Ragnheišur 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] Intensity of Nordic Walking in young females with different peak O2 consumptionCLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 5 2009Toivo Jürimäe Summary The purpose of this cross - sectional study was to determine the physiological reaction to the different intensity Nordic Walking exercise in young females with different aerobic capacity values. Twenty-eight 19,24-year-old female university students participated in the study. Their peak O2 consumption (VO2 peak kg,1) and individual ventilatory threshold (IVT) were measured using a continuous incremental protocol until volitional exhaustion on treadmill. The subjects were analysed as a whole group (n = 28) and were also divided into three groups based on the measured VO2 peak kg,1 (Difference between groups is 1 SD) as follows: 1. >46 ml min,1 kg,1 (n = 8), 2. 41,46 ml min,1 kg,1 (n = 12) and 3. <41 ml min,1 kg,1 (n = 8). The second test consisted of four times 1 km Nordic Walking with increasing speed on the 200 m indoor track, performed as a continuous study (Step 1 , slow walking, Step 2 , usual speed walking, Step 3 , faster speed walking and Step 4 , maximal speed walking). During the walking test expired gas was sampled breath-by-breath and heart rate (HR) was recorded continuously. Ratings of perceived exertion (RPE) were asked using the Borg RPE scale separately for every 1 km of the walking test. No significant differences emerged between groups in HR of IVT (172·4 ± 10·3,176·4 ± 4·9 beats min,1) or maximal HR (190·1 ± 7·3,191·6 ± 7·8 beats min,1) during the treadmill test. During maximal speed walking the speed (7·4 ± 0·4,7·5 ± 0·6 km h,1) and O2 consumption (30·4 ± 3·9,34·0 ± 4·5 ml min,1 kg,1) were relatively similar between groups (P > 0·05). However, during maximal speed walking, the O2 consumption in the second and third groups was similar with the IVT (94·9 ± 17·5% and 99·4 ± 15·5%, respectively) but in the first group it was only 75·5 ± 8·0% from IVT. Mean HR during the maximal speed walking was in the first group 151·6 ± 12·5 beats min,1, in the second (169·7 ± 10·3 beats min,1) and the third (173·1 ± 15·8 beats min,1) groups it was comparable with the calculated IVT level. The Borg RPE was very low in every group (11·9 ± 2·0,14·4 ± 2·3) and the relationship with VO2and HR was not significant during maximal speed Nordic Walking. In summary, the present study indicated that walking is an acceptable exercise for young females independent of their initial VO2 peak level. However, females with low initial VO2 peak can be recommended to exercise with the subjective ,faster speed walking'. In contrast, females with high initial VO2 peak should exercise with maximal speed. [source] | ||||||||||