***TASK*** the task is to summarize an input biomedical literature in six sentences 
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    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: Background Of all older patients that opt for elective colorectal surgery , approximately one-third has one or more postoperative complications , particularly those patients with a low cardiorespiratory fitness ( ventilatory anaerobic threshold ( VAT ) < 11 mL/kg/min ) . A physical exercise training program prior to surgery ( prehabilitation ) can improve their cardiorespiratory fitness . It remains to be seen whether prehabilitation also reduces postoperative complications , as most of the studies so far were rather underpowered , heterogeneous , and biased toward selection of patients with a lower risk of postoperative complications . The primary objective of this study is to evaluate the effects of a three-week prehabilitation program on 30-day postoperative complications in patients with a VAT < 11 mL/kg/min planned for elective colorectal resection for colorectal cancer or dysplasia . Methods In this multicenter prospect i ve r and omized controlled trial , patients ≥ 60 years with colorectal cancer or dysplasia grade I , II , or III , planned for elective colorectal resection in two hospitals in the Netherl and s , will be recruited . Eligible patients must have a score ≤ 7 metabolic equivalents on the veterans-specific activity question naire , and should be able to perform a cardiopulmonary exercise test . A total of 86 patients will be r and omized ( block-stratified r and omization ) to prehabilitation ( intervention group ) or usual care ( control group ) . For final inclusion , VAT should be < 11 mL/kg/min . Three times a week for 3 weeks , a 60-min supervised prehabilitation session will be completed in community physical therapy practice s by the 43 patients in the prehabilitation group , consisting of moderate-to-high intensity interval training to improve cardiorespiratory fitness , and resistance training to improve peripheral muscle strength . Additionally , patients perform home exercises twice a week on a moderate intensity level . The 43 patients in the usual care group will receive usual care . Discussion Optimizing preoperative physical fitness may decrease the postoperative complication rate , may lead to fewer reoperations , less intense clinical care , a shorter length of stay , a more effective surgical planning ( process-optimization ) , fewer readmissions , less intense rehabilitation , shorter rehabilitation period , earlier resumption of work , enhance patient perceived health-related quality of life , and promote performance in daily life . Cost-effectiveness should therefore be expected and evaluated . Trial registration Medical Ethics Committee Twente , Enschede , the Netherl and s ( NL45001.044.13 , September 3 , 2013 ) ; Netherl and s Trial Register ( NTR ; NTR4032 , June 14 , 2013 ) CONTEXT Postoperative pulmonary complications ( PPCs ) after coronary artery bypass graft ( CABG ) surgery are a major source of morbidity and mortality , and increase length of hospital stay and re source utilization . The prehospitalization period before CABG surgery may be used to improve a patient 's pulmonary condition . The efficacy of preoperative inspiratory muscle training ( IMT ) in reducing the incidence of PPCs in high-risk patients undergoing CABG surgery has not yet been determined . OBJECTIVE To evaluate the prophylactic efficacy of preoperative IMT on the incidence of PPCs in high-risk patients scheduled for elective CABG surgery . DESIGN , SETTING , AND PATIENTS A single-blind , r and omized clinical trial conducted at the University Medical Center Utrecht , Utrecht , the Netherl and s , with enrollment between July 2002 and August 2005 . Of 655 patients referred for elective CABG surgery , 299 ( 45.6 % ) met criteria for high risk of developing PPCs , of whom 279 were enrolled and followed up until discharge from hospital . INTERVENTION Patients were r and omly assigned to receive either preoperative IMT ( n = 140 ) or usual care ( n = 139 ) . Both groups received the same postoperative physical therapy . MAIN OUTCOME MEASURES Incidence of PPCs , especially pneumonia , and duration of postoperative hospitalization . RESULTS Both groups were comparable at baseline . After CABG surgery , PPCs were present in 25 ( 18.0 % ) of 139 patients in the IMT group and 48 ( 35.0 % ) of 137 patients in the usual care group ( odds ratio [ OR ] , 0.52 ; 95 % confidence interval [ CI ] , 0.30 - 0.92 ) . Pneumonia occurred in 9 ( 6.5 % ) of 139 patients in the IMT group and in 22 ( 16.1 % ) of 137 patients in the usual care group ( OR , 0.40 ; 95 % CI , 0.19 - 0.84 ) . Median duration of postoperative hospitalization was 7 days ( range , 5 - 41 days ) in the IMT group vs 8 days ( range , 6 - 70 days ) in the usual care group by Mann-Whitney U statistic ( z = -2.42 ; P = .02 ) . CONCLUSION Preoperative IMT reduced the incidence of PPCs and duration of postoperative hospitalization in patients at high risk of developing a pulmonary complication undergoing CABG surgery . TRIAL REGISTRATION is rct n.org Identifier : IS RCT N17691887 Background : As global initiatives increase patient access to surgical treatments , there remains a need to underst and the adverse effects of surgery and define appropriate levels of perioperative care . Methods : We design ed a prospect i ve international 7-day cohort study of outcomes following  elective adult inpatient surgery in 27 countries . The primary outcome was in-hospital complications . Secondary outcomes were death following a complication ( failure to rescue ) and death in hospital . Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay . A single definition of critical care was used for all countries . Results : A total of 474 hospitals in 19 high- , 7 middle- and 1 low-income country were included in the primary analysis . Data included 44 814 patients with a median hospital stay of 4 ( range 2–7 ) days . A total of 7508 patients ( 16.8 % ) developed one or more postoperative complication and 207 died ( 0.5 % ) . The overall mortality among patients who developed complications was 2.8 % . Mortality following complications ranged from 2.4 % for pulmonary embolism to 43.9 % for cardiac arrest . A total of 4360 ( 9.7 % ) patients were admitted to a critical care unit as routine immediately after surgery , of whom 2198 ( 50.4 % ) developed a complication , with 105 ( 2.4 % ) deaths . A total of 1233 patients ( 16.4 % ) were admitted to a critical care unit to treat complications , with 119 ( 9.7 % ) deaths . Despite lower baseline risk , outcomes were similar in low- and middle-income compared with high-income countries . Conclusions : Poor patient outcomes are common after inpatient surgery . Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care . Study registration : IS RCT Flaws in the design , conduct , analysis , and reporting of r and omised trials can cause the effect of an intervention to be underestimated or overestimated . The Cochrane Collaboration ’s tool for assessing risk of bias aims to make the process clearer and more Surgical patients often show physiological and metabolic distress , muscle weakness , and long hospital stays . Physical conditioning might help recovery . We attempted to identify the most responsive measure of aerobic fitness from a four-week pre-surgical aerobic exercise program ( prehabilitation ) in patients undergoing major bowel resection . Twenty-one subjects r and omized two to one ( exercise : control ) scheduled for colorectal surgery . Fourteen subjects [ Body Mass Index ( BMI ) = 27 + /- 6 kg/m(2 ) ; maximal oxygen uptake ( VO(2max ) ) = 22 + /- 10 ml/kg/min ] underwent 3.8 + /- 1.2 weeks ( 27 + /- 8 sessions ) of progressive , structured pre-surgical aerobic exercise training at 40 to 65 % of heart rate reserve ( % HRR ) . Peak power output was the only maximal measure that was responsive to training [ 26 + /- 27 % , Effects Size ( ES ) = 0.24 ; St and ardized Response Mean ( SRM ) = 1.05 ; p < 0.05 ] . For the submaximal measures , heart rate and oxygen uptake during submaximal exercise was most responsive to training ( decrease by 13 % + /- 15 % , ES = -0.24 ; SRM = -0.57 ; and 7 % + /- 6 % , ES = -0.40 ; SRM -0.97 ; p < 0.05 ) at an exercise intensity of 76 + /- 47 W. There was no change to maximal or submaximal measures in the control group . The distance walked over six minutes improved in both groups ( by approximately 30 m ) , but the effect size and t-statistic were higher in the exercise group . Heart rate and oxygen uptake during submaximal exercise , and peak power output are the most responsive measures to four weeks of prehabilitation in subjects with low initial fitness Objective : The aim of this study was to assess the impact of personalized prehabilitation on postoperative complications in high-risk patients undergoing elective major abdominal surgery . Summary Background Data : Prehabilitation , including endurance exercise training and promotion of physical activity , in patients undergoing major abdominal surgery has been postulated as an effective preventive intervention to reduce postoperative complications . However , the existing studies provide controversial results and show a clear bias toward low-risk patients . Methods : This was a r and omized blinded controlled trial . Eligible c and i date s accepting to participate were blindly r and omized ( 1:1 ratio ) to  control ( st and ard care ) or intervention ( st and ard care + prehabilitation )  groups . Inclusion criteria were : i ) age > 70 years ; and /or , ii ) American Society of Anesthesiologists score III/IV .  Prehabilitation covered 3 actions : i ) motivational interview ; ii ) high-intensity endurance training ; and promotion of physical activity . The main study outcome was the proportion of patients suffering postoperative complications . Secondary outcomes included the endurance time ( ET ) during cycle-ergometer exercise . Results : We r and omized 71 patients to the control arm and 73 to intervention . After excluding 19 patients because of changes in the surgical plan , 63 controls and 62 intervention patients were included in the intention-to-treat analysis . The intervention group enhanced aerobic capacity [ & Dgr;ET 135 ( 218 ) % ; P < 0.001 ) , reduced the number of patients with postoperative complications by 51 % ( relative risk 0.5 ; 95 % confidence interval , 0.3–0.8 ; P = 0.001 ) and the rate of complications [ 1.4 ( 1.6 ) and 0.5 ( 1.0 ) ( P = 0.001 ) ] as compared with controls . Conclusion : Prehabilitation enhanced postoperative clinical outcomes in high-risk c and i date s for elective major abdominal surgery , which can be explained by the increased aerobic capacity BACKGROUND The aim of this study was to examine the outcomes of exercise therapy in patients with hepatocellular carcinoma who underwent hepatectomy . METHODS Fifty-one patients with hepatocellular carcinoma were r and omized to diet therapy alone ( n = 25 ) or to exercise in addition to diet therapy ( n = 26 ) . Exercise at the anaerobic threshold of each patient was started 1 month preoperatively , resumed from 1 week postoperatively , and continued for 6 months . RESULTS Whole body mass and fat mass in the exercise group compared with the diet group were significantly decreased at 6 months postoperatively . Fasting serum insulin and the homeostasis model assessment score were also significantly decreased . At 6 months , anaerobic threshold and peak oxygen consumption were significantly increased , while serum insulin and insulin resistance were significantly improved in a high-frequency exercise subgroup compared with a low-frequency group . CONCLUSIONS Perioperative exercise therapy for patients with hepatocellular carcinoma with liver dysfunction may improve insulin resistance associated with hepatic impairment and suggests a benefit to the early resumption of daily exercise after hepatectomy Background : The preoperative period ( prehabilitation ) may represent a more appropriate time than the postoperative period to implement an intervention . The impact of prehabilitation on recovery of function al exercise capacity was thus studied in patients undergoing colorectal resection for cancer . Methods : A parallel-arm single-blind superiority r and omized controlled trial was conducted . Seventy-seven patients were r and omized to receive either prehabilitation ( n = 38 ) or rehabilitation ( n = 39 ) . Both groups received a home-based intervention of moderate aerobic and resistance exercises , nutritional counseling with protein supplementation , and relaxation exercises initiated either 4 weeks before surgery ( prehabilitation ) or immediately after surgery ( rehabilitation ) , and continued for 8 weeks after surgery . Patients were managed with an enhanced recovery pathway . Primary outcome was functional exercise capacity measured using the vali date d 6-min walk test . Results : Median duration of pre 
    Output:
    
Most studies included low-risk surgical patients and considerable variation was observed between prehabilitation programmes in terms of supervision , training context , frequency , intensity , duration and training type .
CONCLUSION : The content of prehabilitation programmes was heterogeneous .
Studies with a high therapeutic validity found unequivocal evidence that prehabilitation had beneficial effects on postoperative outcomes .