***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: Background and Purpose — Despite the importance of exercise training in mitigating cardiovascular risk , the development of exercise programs for people poststroke has been limited by lack of feasibility data concerning cardiopulmonary exercise testing ( CPET ) to inform the exercise prescription . Therefore , we examined the feasibility of CPETs for developing an exercise prescription in people ≥3 months poststroke . Methods — CPET results from 98 consecutively enrolled patients poststroke with motor impairments and 98 age- and sex-matched patients with coronary artery disease were examined at baseline and after 6 months of exercise training . Results — The proportion of patients with stroke and coronary artery disease attaining an intensity sufficient for prescribing exercise at baseline was 68.4 % versus 82.7 % , respectively ( P=0.02 ) and 84.7 % versus 83.8 % ( P=0.9 ) at 6 months . Women were less likely than men poststroke to achieve a sufficient intensity at baseline ( 40 % versus 80.9 % , P<0.001 ) but not at 6 months ( 78.3 % versus 87.1 , P=0.3 ) . A clinical ly relevant abnormality occurred in 11.2 % of stroke and 12.2 % of patients with coronary artery disease on baseline CPETs ( P=0.8 ) and 10.6 % of stroke and 5.9 % of patients with coronary artery disease on the 6-month CPET ( P=0.4 ) . No serious cardiovascular events occurred during 349 CPETs . Conclusions — Most patients after stroke achieved a level of exertion during the CPET sufficient to inform an exercise prescription . At least 1 of 10 patients poststroke developed a clinical ly relevant abnormality on baseline and postprogram CPETs with no serious cardiovascular events . These data support the feasibility and safety of CPETs for prescribing exercise poststroke . Strategies to improve use of baseline CPETs for women poststroke require further investigation This study evaluated the feasibility , safety , and findings from a protocol for exercise-bicycle ergometry in subacute-stroke survivors . Of 117 eligible c and i date s , 14 could not perform the test and 3 discontinued because of cardiac safety criteria . In the 100 completed tests , peak heart rate was 116 + /- 19.1 beats/min ; peak VO(2 ) was 11.4 + /- 3.7 ml x kg x min(-1 ) , peak METs were 3.3 + /- 0.91 , exercise duration was 5.1 + /- 2.84 min , and Borg score was 14 + /- 2.6 . Among 71 tests , anaerobic threshold was achieved in 3.0 + /- 1.7 min with a VO(2 ) of 8.6 + /- 1.7 ml x kg x min(-1 ) . After screening , this protocol is feasible and safe in subacute-stroke survivors with mild to moderate deficits . These stroke survivors have severely limited functional exercise capacity . Research and clinical practice in stroke rehabilitation should incorporate more comprehensive evaluation and treatment of endurance limitations Abstract Purpose : The majority of post-stroke individuals suffer from low exercise capacity as a secondary reaction to immobility . The aim of this study was to prove the concept of feedback-controlled robotics-assisted treadmill exercise ( RATE ) to assess aerobic capacity and guide cardiovascular exercise in severely impaired individuals early after stroke . Method : Subjects underwent constant load and incremental exercise testing using a human-in-the-loop feedback system within a robotics-assisted exoskeleton ( Lokomat , Hocoma AG , CH ) . Inclusion criteria were : stroke onset ≤8 weeks , stable medical condition , non-ambulatory status , moderate motor control of the lower limbs and appropriate cognitive function . Outcome measures included oxygen uptake kinetics , peak oxygen uptake ( VO2peak ) , gas exchange threshold ( GET ) , peak heart rate ( HRpeak ) , peak work rate ( Ppeak ) and accuracy of reaching target work rate ( P-RMSE ) . Results : Three subjects ( 18–42 d post-stroke ) were included . Oxygen uptake kinetics during constant load ranged from 42.0 to 60.2 s. Incremental exercise testing showed : VO2peak range 19.7–28.8 ml/min/kg , GET range 11.6–12.7 ml/min/kg , and HRpeak range 115–161 bpm . Ppeak range was 55.2–110.9 W and P-RMSE range was 3.8–7.5 W. Conclusions : The concept of feedback-controlled RATE for assessment of aerobic capacity and guidance of cardiovascular exercise is feasible . Further research is warranted to vali date the method on a larger scale . Implication s for Rehabilitation Aerobic capacity is seriously reduced in post-stroke individuals as a secondary reaction to immobility . Robotics-assisted walking devices may have substantial clinical relevance regarding assessment and improvement of aerobic capacity early after stroke . Feedback-controlled robotics-assisted treadmill exercise represents a new concept for cardiovascular assessment and intervention protocol s for severely impaired individuals BACKGROUND AND PURPOSE Rehabilitation care after stroke is highly variable and increasingly shorter in duration . The effect of therapeutic exercise on impairments and functional limitations after stroke is not clear . The objective of this study was to determine whether a structured , progressive , physiologically based exercise program for subacute stroke produces gains greater than those attributable to spontaneous recovery and usual care . METHODS This r and omized , controlled , single-blind clinical trial was conducted in a metropolitan area and 17 participating healthcare institutions . We included persons with stroke who were living in the community . One hundred patients ( mean age , 70 years ; mean Orpington score , 3.4 ) consented and were r and omized from a screened sample of 582 . Ninety-two subjects completed the trial . Intervention was a structured , progressive , physiologically based , therapist-supervised , in-home program of thirty-six 90-minute sessions over 12 weeks targeting flexibility , strength , balance , endurance , and upper-extremity function . Main outcome measures were postintervention strength ( ankle and knee isometric peak torque , grip strength ) , upper- and lower-extremity motor control ( Fugl Meyer ) , balance ( Berg and functional reach ) , endurance ( peak aerobic capacity and exercise duration ) , upper-extremity function ( Wolf Motor Function Test ) , and mobility ( timed 10-m walk and 6-minute walk distance ) . RESULTS In the intention-to-treat multivariate analysis of variance testing the overall effect , the intervention produced greater gains than usual care ( Wilk 's lambda=0.64 , P=0.0056 ) . Both intervention and usual care groups improved in strength , balance , upper- and lower-extremity motor control , upper-extremity function , and gait velocity . Gains for the intervention group exceeded those in the usual care group in balance , endurance , peak aerobic capacity , and mobility . Upper-extremity gains exceeded those in the usual care group only in patients with higher baseline function . CONCLUSIONS This structured , progressive program of therapeutic exercise in persons who had completed acute rehabilitation services produced gains in endurance , balance , and mobility beyond those attributable to spontaneous recovery and usual care Background The test – retest reliability for multiple  cardiopulmonary exercise test ( CPX ) variables has not been compared in a single study and the influence of different diseases on test – retest reliability has not been examined . We investigated different measures of test – retest reliability for multiple variables and compared them by category of cardiac or respiratory disease . Methods Patients with chronic obstructive airways disease ( n = 24 ) , heart failure ( n = 43 ) , or severe mitral valve disease ( n = 26 ) were recruited into a prospect i ve study . Each patient underwent two bicycle ergometer tests ; the first , a familiarization test , with a 10 W/min ramp , and the second a personalized ramp based on the results of the familiarization test to elicit maximal effort within 8–10 min . Intraclass correlation coefficients ( ICC ) and coefficients of variation between the two tests were calculated . Influence of potential modifiers was assessed using repeated measures analysis of variance . Results Peak VO2 ( ICC 0.95 , 95 % CI 0.94–0.97 ) , oxygen uptake efficiency slope ( ICC 0.93 , 95 % CI 0.90–0.95 ) , O2 pulse ( ICC 0.96 , 95 % CI 0.94–0.97 ) , and the VE/VCO2 ratio at the nadir ( ICC 0.92 , 95 % CI 0.89–0.95 ) all showed excellent test – retest reliability , with within-subject coefficients of variation < 0.12 . VO2 at the anaerobic threshold ( ICC 0.84 , 95 % CI 0.78–0.89 ) and the VE/VCO2 slope ( ICC 0.88 , 95 % CI 0.79–0.93 ) showed good test – retest reliability , although inferior to peak VO2 . Age , gender , body mass index , disease aetiology , protocol change , and intertest interval did not affect the reliability of most variables . Conclusions CPX showed high test – retest reliability ; certain variables such as peak VO2 and oxygen uptake efficiency slope outperform others . These results identify which variables are most suitable for serial testing of patients with three common disease aetiologies owing to their superior reproducibility Objectives For the measurement of  patient-reported outcomes , such as ( health-related ) quality of life , often many measurement instruments exist that intend to measure the same construct . To facilitate instrument selection , our aim was to develop a highly sensitive search filter for finding studies on measurement properties of measurement instruments in PubMed and a more precise search filter that needs less abstract s to be screened , but at a higher risk of missing relevant studies . Methods A r and om sample of 10,000 PubMed records ( 01 - 01 - 1990 to 31 - 12 - 2006 ) was used as a gold st and ard . Studies on measurement properties were identified using an exclusion filter and h and search ing . Search terms were selected from the relevant records in the gold st and ard as well as from 100 systematic review s of measurement properties and combined based on sensitivity and precision . The performance of the filters was tested in the gold st and ard as well as in two validation sets , by calculating sensitivity , precision , specificity , and number needed to read . Results We identified 116 studies on measurement properties in the gold st and ard . The sensitive search filter was able to retrieve 113 of these 116 studies ( sensitivity 97.4 % , precision 4.4 % ) . The precise search filter had a sensitivity of 93.1 % and a precision of 9.4 % . Both filters performed very well in the validation sets . Conclusion The use of these search filters will contribute to evidence -based selection of measurement instruments in all medical fields The assessment of functional capacity reflects the ability to perform activities of daily living that require sustained aerobic metabolism . The integrated efforts and health of the pulmonary , cardiovascular , and skeletal muscle systems dictate an individual ’s functional capacity . Numerous investigations have demonstrated that the assessment of functional capacity provides important diagnostic and prognostic information in a wide variety of clinical and research setting s. This scientific statement , an up date of the previously published American Heart Association ( AHA ) document,1 highlights the major clinical and research applications of functional capacity assessment . For a comprehensive review of exercise testing , the reader is referred to the American College of Cardiology (ACC)/AHA Guidelines for Exercise Testing.2,3 Functional capacity is the ability of an individual to perform aerobic work as defined by the maximal oxygen uptake ( Vo2max ) , that is , the product of cardiac output and arteriovenous oxygen ( a−Vo2 ) difference at physical exhaustion , as shown in the following equation : ! [Formula][1 ] Where HR indicates heart rate and SV indicates stroke volume . Because Vo2max typically is achieved by exercise that involves only about half of the total body musculature , it is generally believed that Vo2max is limited by maximal cardiac output rather than peripheral factors.4 Although Vo2max is measured in liters of oxygen per minute , it usually is expressed in milliliters of oxygen per kilogram of body weight per minute to facilitate intersubject comparisons . In addition , functional capacity , particularly when estimated from the work rate achieved rather than directly measured Vo , is frequently expressed in metabolic equivalents ( METs ) , with 1 MET representing the resting energy expenditure ( ≈3.5 mL O2 · kg−1 · min−1 ) . In this instance , functional capacity is commonly expressed clinical ly as a multiple of the resting metabolic rate . Vo2max … [ 1 ] : Background Exercise testing devices for evaluating cardiopulmonary fitness in patients with severe disability after stroke are lacking , but we have adapted a robotics-assisted tilt table ( RATT ) for cardiopulmonary exercise testing ( CPET ) . Using the RATT in a sample of patients after stroke , this study aim ed to investigate test-retest reliability and repeatability of CPET and to prospect ively investigate changes in cardiopulmonary outcomes over a period of four weeks . Methods Stroke patients with all degrees of disability underwent 3 separate CPET sessions : 2 tests at baseline ( TB1 and TB2 ) and 1 test at follow up ( TF ) . TB1 and TB2 were at least 24 h apart . TB2 and TF were 4 weeks apart . A RATT equipped with force sensors in the thigh cuffs , a work rate estimation algorithm and a real-time visual feedback system was used to guide the patients ’ exercise work rate during CPET . Test-retest reliability and repeatability of CP 
    Output:
    
No judgement could be made on which protocol is " best " for measuring VO2max in persons after stroke due to lack of high- quality studies on the measurement properties of the cardiopulmonary exercise test