***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Alterations in circulating angiogenic cells ( CAC ) and endothelial progenitor cells ( EPC ) , known to contribute to endothelial repair , could explain the reversal of endothelial function in response to exercise training . Moreover , training-induced vascular remodeling might affect the acute response of EPC and CAC following a single exercise bout . We studied the impact of exercise training on CAC function and numbers of CD34+/KDR+ EPC in patients with chronic heart failure ( CHF ) and we assessed the effect of acute exercise on CAC and EPC in sedentary and trained patients . Twenty-one sedentary CHF patients underwent 6-month exercise training  and were compared to a non-trained control group ( n = 17 ) and 10 healthy age-matched subjects . At baseline and follow-up , flow-mediated dilation was assessed and grade d exercise testing ( GXT ) was performed . Before and immediately after GXT , CAC migratory capacity was assessed in vitro and circulating CD34+/KDR+ EPC were quantified using flow cytometry . At baseline , CAC migration was significantly impaired in sedentary CHF patients but normalized acutely after GXT . Training corrected endothelial dysfunction , which coincided with a 77 % increase in CAC migration ( P = 0.0001 ) . Moreover , the GXT-induced improvement detected at baseline was no longer observed after training . Numbers of CD34+/KDR+ EPC increased following 6-month exercise training ( P = 0.021 ) , but were not affected by GXT , either prior or post-training . In conclusion , the present findings demonstrate for the first time that exercise training in CHF reverses CAC dysfunction and increases numbers of CD34+/KDR+ EPC , which is accompanied by improvement of peripheral endothelial function . The acute exercise-induced changes in CAC function wane with exercise training , suggesting that repetitive exercise bouts progressively lead to functional endothelial repair Background — Exercise training reduces the symptoms of chronic heart failure . Which exercise intensity yields maximal beneficial adaptations is controversial . Furthermore , the incidence of chronic heart failure increases with advanced age ; it has been reported that 88 % and 49 % of patients with a first diagnosis of chronic heart failure are > 65 and > 80 years old , respectively . Despite this , most previous studies have excluded patients with an age > 70 years . Our objective was to compare training programs with moderate versus high exercise intensity with regard to variables associated with cardiovascular function and prognosis in patients with postinfa rct ion heart failure . Methods and Results — Twenty-seven patients with stable postinfa rct ion heart failure who were undergoing optimal medical treatment , including & bgr;-blockers and angiotensin-converting enzyme inhibitors ( aged 75.5±11.1 years ; left ventricular [ LV ] ejection fraction 29 % ; & OV0312;o2peak 13 mL · kg−1 · min−1 ) were r and omized to either moderate continuous training ( 70 % of highest measured heart rate , ie , peak heart rate ) or aerobic interval training ( 95 % of peak heart rate ) 3 times per week for 12 weeks or to a control group that received st and ard advice regarding physical activity . & OV0312;o2peak increased more with aerobic interval training than moderate continuous training ( 46 % versus 14 % , P<0.001 ) and was associated with reverse LV remodeling . LV end-diastolic and end-systolic volumes declined with aerobic interval training only , by 18 % and 25 % , respectively ; LV ejection fraction increased 35 % , and pro-brain natriuretic peptide decreased 40 % . Improvement in brachial artery flow-mediated dilation ( endothelial function ) was greater with aerobic interval training , and mitochondrial function in lateral vastus muscle increased with aerobic interval training only . The MacNew global score for quality of life in cardiovascular disease increased in both exercise groups . No changes occurred in the control group . Conclusions — Exercise intensity was an important factor for reversing LV remodeling and improving aerobic capacity , endothelial function , and quality of life in patients with postinfa rct ion heart failure . These findings may have important implication s for exercise training in rehabilitation programs and future studies Introduction Physical fitness is an important prognostic factor in heart failure ( HF ) . To improve fitness , different types of exercise have been explored , with recent focus on high-intensity interval training ( HIT ) . We comprehensively compared effects of HIT versus continuous training ( CT ) in HF patients NYHA II-III on physical fitness , cardiovascular function and structure , and quality of life , and hypothesize that HIT leads to superior improvements compared to CT . Methods Twenty HF patients ( male : female 19:1 , 64±8 yrs , ejection fraction 38±6 % ) were allocated to 12-weeks of HIT ( 10 * 1-minute at 90 % maximal workload — alternated by 2.5 minutes at 30 % maximal workload ) or CT ( 30 minutes at 60–75 % of maximal workload ) . Before and after intervention , we examined physical fitness ( incremental cycling test ) , cardiac function and structure ( echocardiography ) , vascular function and structure ( ultrasound ) and quality of life ( SF-36 , Minnesota living with HF question naire ( MLHFQ ) ) . Results Training improved maximal workload , peak oxygen uptake ( VO2peak ) related to the predicted VO2peak , oxygen uptake at the anaerobic threshold , and maximal oxygen pulse ( all P<0.05 ) , whilst no differences were present between HIT and CT ( N.S. ) . We found no major changes in resting cardiovascular function and structure . SF-36 physical function score improved after training ( P<0.05 ) , whilst SF-36 total score and MLHFQ did not change after training ( N.S. ) . Conclusion Training induced significant improvements in parameters of physical fitness , although no evidence for superiority of HIT over CT was demonstrated . No major effect of training was found on cardiovascular structure and function or quality of life in HF patients NYHA II-III . Trial Registration Nederl and s Trial Register Background A reduction in number and function of endothelial progenitor cells ( EPCs ) occurs in both physiologic aging and chronic heart failure ( CHF ) . We assessed whether disease and aging have additive effects on EPCs or whether beneficial effects of exercise training are diminished in old age . Methods We r and omized 60 patients with stable CHF and 60 referent controls to a training or a control group . To detect possible aging effects we included subjects below 55 ( young ) and above 65 years ( older ) . Subjects in the training group exercised four times daily at 60 % to 70 % of VO2max for four weeks under supervision . At baseline and after the intervention the number and function of EPCs were assessed . Results As compared with young referent controls , older referent controls showed at baseline a reduced EPC number ( young : 190 ± 37 CD34/KDR positive cells/ml blood ; older : 131 ± 26 CD34/KDR positive cells/ml blood ; p < 0.05 ) and function ( young : 230 ± 41 migrated cells/1000 plated cells ; older : 185 ± 28 cells/1000 plated cells ; p < 0.05 ) . In young and older CHF patients EPC-number ( young : 85 ± 21 CD34/KDR positive cells/ml blood ; older : 78 ± 20 CD34/KDR positive cells/ml blood ) and EPC-function ( young : 113 ± 26 cells/1000 plated cells ; older : 120 ± 27 cells/1000 plated cells ) were impaired . As a result of exercise training , EPC function improved by 24 % in older referent controls ( p < 0.05 ) , while it remained unchanged in young training referent controls and controls respectively . In young and older patients with CHF four weeks of exercise training result ed in a significant improvement in EPC numbers and EPC function ( young : number + 66 % function + 43 % ; p < 0.05 ; older : number + 69 % function + 36 % ; p < 0.05 ) . These results were accompanied by a significant increase in flow mediated dilatation in the training groups of young/older CHF patients and in older referent controls . Conclusions Four weeks of exercise training are effective in improving EPC number and EPC function in CHF patients . These training effects were not impaired among older patients , emphasizing the potentials of rehabilitation interventions in a patient group where CHF has a high prevalence Introduction : Several established tools are available to assess study quality and reporting of r and omized controlled trials ; however , these tools were design ed with clinical intervention trials in mind . In exercise training intervention trials some of the traditional study quality criteria , such as participant or research er blinding , are extremely difficult to implement . Methods : We developed the Tool for the assEssment of Study qualiTy and reporting in EXercise ( TESTEX ) – a study quality and reporting assessment tool , design ed specifically for use in exercise training studies . Our tool is a 15-point scale ( 5 points for study quality and 10 points for reporting ) and addresses previously unmentioned quality assessment criteria specific to exercise training studies . Results : There were no systematic differences between the summated TESTEX scores of each observer [ H(2 ) = 0.392 , P = 0.822 ] . There was a significant association between the summated TESTEX scores of the three observers , with almost perfect agreement between observers 1 and 2 [ intra-class correlation coefficient ( ICC ) = 0.93 , 95 % confidence interval ( CI ) 0.82–0.97 , P < 0.001 ] , observers 1 and 3 ( ICC = 0.96 , 95 % CI 0.89–0.98 , P < 0.001 ) and observers 2 and 3 ( ICC = 0.91 , 95 % CI 0.75–0.96 , P < 0.001 ) . Conclusions : The TESTEX scale is a new , reliable tool , specific to exercise scientists , that facilitates a comprehensive review of exercise training trials Background —In stable coronary artery disease ( CAD ) , exercise training has well-documented positive effects on arterial endothelial function . NO derived from endothelial NO synthase ( eNOS ) is regarded as a protective factor against atherosclerosis . The aim of the present study was to investigate the effects of exercise training on the endothelial function in relation to the expression of eNOS and Akt-dependent eNOS phosphorylation in the left internal mammary artery ( LIMA ) of patients with stable CAD . Methods and Results —In 17 training patients ( T ) and 18 control patients ( C ) , endothelium-dependent vasodilation and average peak flow velocity ( APV ) in response to  acetylcholine  were measured invasively at study beginning and after 4 weeks in the LIMA . In LIMA tissue sample d during bypass surgery , eNOS expression and content of pospho-eNOS-Ser1177 , Akt , and phospho-Akt were determined by Western blot and quantitative reverse transcriptase – polymerase chain reaction . After exercise training , LIMA APV in response to acetylcholine was increased by 56±8 % ( from + 48±8 % at beginning to + 104±11 % after 4 weeks , P < 0.001 ) . Patients in T had a 2-fold higher eNOS protein expression ( T 1.0±0.7 versus C 0.5±0.3 arbitrary units , P < 0.05 ) and 4-fold higher eNOS Ser1177-phosphorylation levels in LIMA-endothelium ( 1.2±0.9 versus 0.3±0.2 arbitrary units , P < 0.01 ) . A linear correlation was confirmed between Akt phosphorylation and phospho-eNOS levels ( R = 0.80 , P < 0.05 ) and between phospho-eNOS and & Dgr ; APV ( R = 0.59 , P < 0.05 ) . Conclusions —Exercise training in stable CAD leads to an improved agonist-mediated endothelium-dependent vasodilatory capacity . The change in acetylcholine-induced vasodilatation was closely related to a shear stress – induced/Akt-dependent phosphorylation of eNOS on Ser1177 BACKGROUND The purpose of this study was to determine the effects of systemic exercise training on endothelium-mediated arteriolar vasodilation of the lower limb and its relation to exercise capacity in chronic heart failure ( CHF ) . Endothelial dysfunction is a key feature of CHF , contributing to increased peripheral vasoconstriction and impaired exercise capacity . Local h and grip exercise has previously been shown to enhance endothelium-dependent vasodilation in conduit and resistance vessels in CHF . METHODS AND RESULTS Twenty patients were prospect ively r and omized to a training group ( n=10 , left ventricular ejection fraction [ LVEF ] 24+/-4 % ) or a control group ( n=10 , LVEF 23+/-3 % ) . At baseline and after 6 months , peak flow velocity was measured in the left femoral artery using a Doppler wire ; vessel diameter was determined by quantitative angiography . Peripheral blood flow was calculated from average peak velocity ( APV ) and arterial cross-sectional area . After exercise training , nitroglycerin-induced endothelium-independent vasodilation remained unaltered ( 271 % versus 281 % , P = NS ) . Peripheral blood flow improved 
    Output:
    
CONCLUSION Overall exercise training  improved endothelial function , assessed via FMD , and endothelial progenitor cells in heart failure patients