***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: OBJECTIVES Peak oxygen uptake ( VO2 peak ) increases more after high intensity interval training compared to isocaloric moderate exercise in patients with coronary heart disease ( CHD ) . We assessed the impact of exercise intensity during high intensity intervals on the increase in VO2 peak . DESIGN / METHODS We included 112 patients with coronary heart disease who had participated in r and omized trials of interval training  consisting of four times four minutes intervals at 85 - 95 % of heart rate maximum ( HRmax ) for 12 weeks . Exercise intensity was calculated for each patient using HR during the two last minutes of each interval , expressed as percentage of HRmax . We used a univariate general linear model with VO2 peak increase as the dependent variable and percentage of HRmax , age , number of exercise sessions , and baseline VO2 peak as covariates . Exercise intensity was also divided into three categories ; < 88 % , 88 - 92 % , and > 92 % of HRmax , and these categories were used as a fixed factor in the model . RESULTS VO2 peak increased by 3.9 ( SD 3.1 ) mL kg(-1)min(-1 ) , equal to 11.9 % after 23.4 exercise sessions . Percentage of HRmax had a significant effect on increase in VO2 peak , both as a continuous ( p=0.019 ) and categorical variable ( p=0.020 ) . The estimated marginal means and 95 % confidence intervals of the increase in VO2 peak for the three intensity categories were 3.1 ( 2.0 , 4.2 ) , 3.6 ( 2.8 , 4.4 ) , and 5.2 ( 4.1 , 6.3 ) for the < 88 % , the 88 - 92 % , and the > 92 % category , respectively . CONCLUSIONS Even within the high intensity training zone , exercise intensity was an important determinant for improving VO2 peak in patients with coronary heart disease The oxygen uptake efficiency slope ( OUES ) is a submaximal index incorporating cardiovascular , peripheral , and pulmonary factors that determine the ventilatory response to exercise . The purpose of this study was to evaluate the effects of continuous exercise training and interval exercise training on the OUES in patients with coronary artery disease . Thirty-five patients ( 59.3±1.8 years old ; 28 men , 7 women ) with coronary artery disease were r and omly divided into two groups : continuous exercise training ( n=18 ) and interval exercise training ( n=17 ) . All patients performed grade d exercise tests with respiratory gas analysis before and 3 months after the exercise-training program to determine ventilatory anaerobic threshold ( VAT ) , respiratory compensation point , and peak oxygen consumption ( peak VO2 ) . The OUES was assessed based on data from the second minute of exercise until exhaustion by calculating the slope of the linear relation between oxygen uptake and the logarithm of total ventilation . After the interventions , both groups showed increased aerobic fitness ( P<0.05 ) . In addition , both the continuous exercise and interval exercise training groups demonstrated an increase in OUES ( P<0.05 ) . Significant associations were observed in both groups : 1 ) continuous exercise training  ( OUES and peak VO2 r=0.57 ; OUES and VO2 VAT r=0.57 ) ; 2 ) interval exercise training ( OUES and peak VO2 r=0.80 ; OUES and VO2 VAT r=0.67 ) . Continuous and interval exercise training result ed in a similar increase in OUES among patients with coronary artery disease . These findings suggest that improvements in OUES among CAD patients after aerobic exercise training may be dependent on peripheral and central mechanisms 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 Background Heart rate recovery ( HRR1 ) immediately after exercise reflects parasympathetic activity , which is markedly attenuated in chronic heart failure ( CHF ) patients . The aim of our study was to examine both continuous and interval exercise training effects on HRR1 in these patients . Design The population study consisted of 29 stable CHF patients that participated at a rehabilitation program of 36 sessions , three times per week . Of the 29 patients , 24 completed the program . Patients were r and omly assigned to interval { n = 10 [ 100 % peak work rate ( WRp ) for 30 s , alternating with rest for 30 s ] } and to continuous training [ n = 14 ( 50%WRp ) ] . Methods All patients performed a symptom-limited cardiopulmonary exercise test on a cycle ergometer before and after the completion of the program . Measurements included peak oxygen uptake ( VO2p ) , anaerobic threshold ( AT ) , WRp , first degree slope of VO2 during the first minute of recovery ( VO2/t-slope ) , chronotropic response [ % chronotropic reserve ( CR ) = ( peak HR - resting HR ) × 100/(220 - age - resting HR ) ] , HRR1 ( HR difference from peak exercise to one minute after ) . Results After the completion of the rehabilitation program there was a significant increase of WRp , VO2p , AT and VO2/t-slope ( by 30 % , P=0.01 ; 6 % , P=0.01 ; 10 % , P=0.02 ; and 27 % , P=0.03 respectively for continuous training and by 21 % , P≤0.05 ; 8 % , P=0.01 ; 6 % , P = NS ; and 48 % , P=0.02 respectively for interval training ) . However , only patients exercised under the continuous training regime had a significant increase in HRR1 ( 15.0±9.0 to 24.0±12bpm ; P=0.02 ) and CR ( 57±19 to 72±21 % , P=0.02 ) , in contrast with those assigned to interval training ( HRR1 : 21 ± 11 to 21 ± 8 bpm ; P = NS and CR : 57 ± 18 to 59 ± 21 % , P = NS ) . Conclusions Both continuous and interval exercise training program improves exercise capacity  in CHF patients . However , continuous rather than interval exercise training improves early HRR1 , a marker of parasympathetic activity , suggesting a greater contribution to the autonomic nervous system Objective . To study the effect of aerobic treadmill exercise training with different intensity on left ventricular ( LV ) function in patients with stable coronary artery disease , using Strain Rate- and Tissue Doppler Imaging . Design . Seventeen patients were r and omly assigned to either moderate ( 50–60 % of peak oxygen uptake ( VO2peak ) ) or high intensity exercise ( 80–90 % of VO2peak ) for 10 weeks . Results . The increase of VO2peak was significantly higher ( p=0.01 ) in the high intensity group ( 17 vs. 8 % ) . Mean LV early diastolic strain rate increased in the high , but not in the moderate , intensity group . For systolic strain rate or mitral annular velocities there were no change after training in either group . Conclusions . Aerobic treadmill exercise improves early diastolic relaxation in patients with stable coronary artery disease , measured by the mean LV early diastolic strain rate BACKGROUND Peak oxygen uptake ( Vo(2peak ) ) strongly predicts mortality in cardiac patients . We compared the effects of aerobic interval training ( AIT ) versus moderate continuous training ( MCT ) on Vo(2peak ) and quality of life after  coronary artery bypass grafting ( CABG ) . METHODS Fifty-nine CABG patients were r and omized to either AIT at 90 % of maximum heart rate or MCT at 70 % of maximum heart rate , 5 d/wk , for 4 weeks at a rehabilitation center . Primary outcome was Vo(2peak ) , at baseline , after rehabilitation ( 4 weeks ) , and after 6 months of home-based exercise ( 6 months ) . RESULTS Vo(2peak ) increased between baseline and 4 weeks in AIT ( 27.1 + /- 4.5 vs 30.4 + /- 5.5 mL.kg(-1).min(-1 ) , P < .001 ) and MCT ( 26.2 + /- 5.2 vs 28.5 + /- 5.6 mL.kg(-1).min(-1 ) , P < .001 ; group difference , not significant ) . Aerobic interval training increased Vo(2peak ) between 4 weeks and 6 months ( 30.4 + /- 5.5 vs 32.2 + /- 7.0 mL.kg(-1).min(-1 ) , P < .001 ) , with no significant change in MCT ( 28.5 + /- 5.6 vs 29.5 + /- 5.7 mL.kg(-1).min(-1 ) ) . Quality of life improved in both groups from baseline to 4 weeks , remaining improved at 6 months . There were no changes in echocardiographic systolic and diastolic left ventricular function . Adiponectin increased between 4 weeks and 6 months in both groups ( group differences , not significant ) . CONCLUSIONS Four weeks of intense training increased Vo(2peak ) significantly after both AIT and MCT . Six months later , the AIT group had a significantly higher Vo(2peak ) than MCT . The results indicate that AIT and MCT increase Vo(2peak ) similarly in the short term , but with better long-term effect of AIT after CABG We found that interval training provides an effective means to improve the cardiovascular fitness and health status of highly functional patients with coronary artery disease . We also revealed that interval training improves anaerobic tolerance to a greater extent than the traditional exercise training model without increasing the risk to the patient . This research supports the implementation of interval training for highly functional patients with coronary artery disease 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 : Small studies have suggested that high- 
    Output:
    
Conclusion This meta- analysis adds further evidence to the clinical ly significant larger increase in peak oxygen uptake  following aerobic interval training vs. aerobic continuous training in patients with coronary artery disease and chronic heart failure .