***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: Little information is available about the effects of inspiratory muscle training in patients with cystic fibrosis ( CF ) . In this study the effects of inspiratory-threshold loading in patients with CF on strength and endurance of the inspiratory muscles , pulmonary function , exercise capacity , dyspnoea and fatigue were evaluated . Sixteen patients were assigned to one of two groups using the minimization method : eight patients in the training group and eight patients in the control group . The training was performed using an inspiratory-threshold loading device . Patients were instructed to use the threshold trainer 20 min a day , 5 days a week for 6 weeks . Patients in the training group trained at inspiratory threshold loads up to 40 % of maximal static inspiratory pressure ( Pimax ) and patients in the control group got ' sham ' training at a load of 10 % of Pimax . No significant differences were found among the two groups in gender , age , weight , height , pulmonary function , exercise capacity , inspiratory-muscle strength and inspiratory-muscle endurance before starting the training programme . Mean ( SD ) age in the control group was 19 ( 5.5 ) years , mean ( SD ) age in the training group was 17 ( 5.2 ) years .  Mean FEV1 in both groups was 70 % predicted , mean inspiratory-muscle strength in both groups was above 100 % predicted . All patients except one , assigned to the training group , completed the programme . After 6 weeks of training , mean inspiratory-muscle endurance ( % Pimax ) in the control group increased from 50 % to 54 % ( P = 0.197 ) ; in the training group mean inspiratory muscle endurance ( % Pimax ) increased from 49 % to 66 % ( P = 0.003 ) . Statistical analysis showed that the change in inspiratory-muscle endurance ( % Pimax ) in the training group was significantly higher than in the control group ( P = 0.012 ) . After training , in the training group there was a tendency of improvement in Pimax with an increase from 105 to 123 % predicted , which just fell short of statistical significance ( P = 0.064 ) . After training no significant differences were found in changes from baseline in pulmonary function , exercise capacity , dyspnoea and fatigue . It is concluded that low-intensity inspiratory-threshold loading at 40 % of Pimax was sufficient to elicit an increased inspiratory-muscle endurance in patients with CF STUDY OBJECTIVE Exercise has the potential to improve the ability of a patient with cystic fibrosis ( CF ) to cope with the physical dem and s of everyday life , and may improve prognosis . The purpose of this study was to compare the effects of a home-based , semi-supervised , upper-body strength-training regimen with a similarly structured aerobic training regimen . DESIGN Data were collected during a 1-year r and omized clinical trial . SETTING Counselors conducted in-home visits with the participants once per week for the first 8 weeks followed by monthly visits for the remainder of the study . PATIENTS Sixty-seven patients with CF , aged 8 to 18 years , participated in the trial . INTERVENTION Participants in both exercise conditions were encouraged to exercise at least three times per week for 1 year . Each child in the aerobic group was given a stair-stepping machine , and each child in the upper-body strength training group was given an upper-body-only weight-resistance machine . MEASURES AND RESULTS Aerobic fitness , pulmonary function , quality of life , and strength were measured at baseline , at 6 months , and at 12 months . Strength training increased the maximum weight lifted for biceps curls significantly more than aerobic training ( p < 0.02 ) . However , this differential did not remain significant after control for increase in height . Both training procedures were associated with increased strength ( p < 0.002 ) and physical work capacity ( PWC ) [ p < 0.033 ] . CONCLUSIONS We concluded that strength and aerobic training may increase upper-body strength , and that both types of training may increase PWC for children with CF . Future trials should be conducted with no-training control subjects and larger sample s to increase statistical power OBJECTIVE To assess and compare immediate effects of chest physiotherapy with positive expiratory pressure ( PEP ) versus oscillating PEP on transcutaneously measured blood-gas tensions in patients with cystic fibrosis . METHODS Fifteen patients ( mean age 12.5 y , range 6.9 - 21.5 y ) participated . The treatments were r and omized and performed on 2 separate occasions , 8 weeks apart . Spirometry was conducted before and after each treatment . We transcutaneously measured  oxygen tension ( P(tO2 ) . RESULTS There were no changes in spirometry values . During PEP , different trends in blood-gas tension were seen , and there were no consistent changes . During oscillating PEP  , P(tO2 ) increased and P(tCO2 ) decreased . During oscillating PEP  , P(tCO2 ) was lower and the intra-individual change in P(tCO2 ) was more pronounced than during PEP . The results obtained immediately after oscillating PEP showed a higher P(tO2 ) and a lower P(tCO2 ) than with PEP . CONCLUSION PEP and oscillating PEP can both cause transitory effects on blood gases in patients with cystic fibrosis . However , oscillating PEP alters blood-gas tensions more than does PEP , and hyperventilation during oscillating PEP may reduce treatment time BACKGROUND To investigate the effects of inhaled beta-agonists on sub-maximal and maximal exercise capacity , breathing pattern , dyspnoea , leg-discomfort and spirometry in patients with cystic fibrosis ( CF ) . OBJECTIVES Eight patients performed two maximal incremental cycle-ergometry tests on separate days with inhaled placebo or salbutamol ( 600 microg ) administered before each test in a r and omized , double-blind , placebo-controlled crossover trial . Primary outcomes were exercise duration ( Exdur ) in seconds ( s ) and maximal oxygen uptake ( VO2max ) in litres/minute ( L/min ) . Forced expiratory volume in 1 s ( FEV1 ) was measured immediately pre-inhaler , post-inhaler and post-exercise . Dyspnoea and leg-discomfort were assessed post-exercise . RESULTS Within-day FEV1 comparisons demonstrated that the placebo test day FEV1 improved significantly post-exercise ( 0.11 L , p<0.05 ) and the salbutamol test day FEV1 improved significantly post-inhaler ( 0.22 L , p<0.001 ) and post-exercise ( 0.07 L , p<0.01 ) . Between-day FEV1 comparisons demonstrated significant improvements in post-inhaler ( 0.17 L , p<0.05 ) and post-exercise ( 0.13 L , p<0.05 ) FEV1 following salbutamol . Sub-maximal and maximal exercise showed no significant difference as shown by Exdur ( 547+/-154 s vs. 529+/-127 s ) and VO2max ( 1.9+/-0.5 L/min vs. 1.9+/-0.6 L/min ) . No significant change in breathing pattern , dyspnoea or leg-discomfort was detected . The study had a power of 92 % to detect a 10 % improvement in Exdur . CONCLUSIONS In adults with CF , salbutamol improves post-exercise FEV1 and is safe when administered immediately before exercise but does not improve exercise capacity , exercise-induced dyspnoea or leg-discomfort Although exercise may be beneficial in cystic fibrosis ( CF ) , patients ' low tolerance to climatic heat stress means that physical exertion can increase morbidity and mortality . We postulated that the high salt content of CF patients ' sweat and the consequent absence of body-fluid hyperosmolality during a long episode of sweating might deprive such patients of a thirst stimulus . Eight children with CF ( four boys , four girls ; aged 9.5 - 14.1 years ) and eight controls , matched for age and sex , attended two r and omly ordered sessions of exercise ( cycling ) in a chamber at 31 - 33 degrees C , relative humidity 43 - 47 % . 20 min bouts of exercise ( at 45 % of predetermined maximum oxygen uptake ) were interspersed with 25 min rest periods . At one session , chilled water was given every 15 - 20 min to replace fluid lost ; at the other , drinking was guided by the child 's thirst . At the thirst-guided session , CF patients drank much less than the controls did ( 0.80 % vs 1.73 % initial body weight ) and lost twice as much fluid ( 1.57 % vs 0.78 % initial body weight ) . The recovery of heart rate after exercise was slower in CF patients , but there were no other signs of heat strain . The groups did not differ in any variable during the forced drinking session . We conclude that children with CF underestimate their fluid needs and undergo excessive dehydration during extended exposure to hot conditions Relationships among nutritional status and skeletal and respiratory muscle function were examined in 16 children with cystic fibrosis ( CF ) and mild lung disease ( FEV1 95 + /- 16 % predicted ) . Subjects were r and omly assigned to receive ( or not ) noninvasive nutritional supplementation at 25 % of normal energy recommendations for 6 mo . Skeletal muscle strength and power were similar to those of healthy children as were respiratory muscle strength and endurance . Stepwise-regression analysis indicated that changes in skeletal muscle strength and energy intake correlated significantly with growth [ weight ( kg ) = 1.90 - 0.60 ( Tanner Stage ) + 0.49 ( maximum voluntary strength ( Nm ) + 0.03 ( energy intake , % RNI ) , r = 0.76 , P < 0.05 ] , though body composition , protein biochemistry , muscle power , respiratory muscle strength , and use of dietary supplements did not . Thus , changes in skeletal muscle strength may be a functional index of changes in nutritional status in CF . Dietary supplementation per se was not associated with functional improvement The effects of supplemental O2 on recovery from  supramaximal exercise  and subsequent performance remain unknown . If recovery from exercise could be enhanced in individuals with chronic lung disease , subsequent supramaximal exercise performance could also be improved . Recovery from  supramaximal exercise  and subsequent supramaximal exercise performance  were assessed after 10 min of breathing 100 % O2 or room air ( RA ) in 17 cystic fibrosis ( CF ) patients [ 25 + /- 10 ( SD ) yr old , 53 % men , forced expired volume in 1 s = 62 + /- 21 % predicted ] and 17 normal subjects ( 25 + /- 8 yr old , 59 % men , forced expired volume in 1 s = 112 + /- 15 % predicted ) .  Supramaximal performance  was assessed as the work of  sustained bicycling at a load of 130 % of the maximum load achieved during a grade d maximal exercise .  Peak minute ventilation ( VE ) and heart rate ( HR ) were lower in CF patients at the end of each supramaximal bout than in controls . In CF patients , single-exponential time decay constants indicated faster recovery of HR ( tau HR = 86 + /- 8 and 73 + /- 6 s in RA and O2 , respectively , P < 0.01 ) . Similarly , fast and slow time constants of two-exponential equations providing the best fit for ventilatory recovery were improved in CF patients during O2 breathing ( tau 1VE = 132.1 + /- 10.5 vs. 82.5 + /- 10.4 s ; tau 2VE = 880.3 + /- 300.1 vs. 368.6 + /- 107.1 s , P < 0.01 ) . However , no such improvements occurred in controls . Supramaximal performance after O2 improved in CF patients ( 109 + /- 6 % of the 1st bout after O2 vs. 94 + /- 6 % in RA , P < 0.01 ) . O2 supplementation had no effect on subsequent performance in controls ( 97 + /- 3 % in O2 vs. 93 + /- 3 % in RA ) . We conclude that supplemental O2 after a short bout of supramaximal exercise accelerates recovery and preserves subsequent supramaximal performance in patients with CF HYPOTHESIS We hypothesized that aerosol distribution in the lungs of patients with cystic fibrosis changes with positive expiratory pressure ( PEP ) . METHODS Eight patients were r and omized to one of 2 conditions . On one study day , patients inhaled saline aerosol containing 99mtechnetium generated by a Pari LC Plus nebulizer and exhaled through a Pari PEP device . On another day , the same patients exhaled through a low-resistance Pari filter ( no PEP ) . Afterwards , they underwent gamma-camera lung imaging . Images were analyzed for lung deposition fraction , expressed as a percent of the initial nebulizer activity , and deposition pattern , expressed in terms of inner-outer and apical-basal ratios . RESULTS Lung deposition fraction was significantly lower with the Pari PEP device ; the mean + SD deposition fraction was 6.10 + 3.05 % ( median 6.20 % ) with PEP , compared to 10.76 + 4.52 % ( median 10.32 % ) ( p = 0.0078 ) without PEP . The inner-outer ratio was 2.01 + 0.69 ( median 2.23 ) with PEP , 
    Output:
    
Meta-analyses were limited to forced expiratory volume in 1 second ( FEV1 ) and forced vital capacity ( FVC ) , which showed no difference in effect between the IMT group and the sham and /or control group .
Individual study results were inconclusive for improvement in inspiratory muscle strength .
Conclusion : The benefit of IMT in adolescents and adults with cystic fibrosis for outcomes of inspiratory muscle function is supported by weak evidence .
Its impact on exercise capacity , dyspnoea and quality of life is not clear .