human
***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: Subjects performed isoload variable resistance exercise ( REX ) 3 days per week . After 10 weeks , they received a double-blind albuterol ( n = 11 ) or placebo ( n = 11 ) capsule assignment with no crossover and continued training . During the first week of capsule administration , dosages were increased from 4 mg to 16 mg daily and then maintained for 14 days . At weeks 0 , 10 , and 13 , we measured upper arm and thigh cross-sectional area , knee and elbow extensor and flexor ( KE , KF , EE , EF ) strength at 3 angular velocities , and lean body mass . Data after 10 weeks showed insignificant between-group differences . From weeks 10–13 , as subjects continued REX training , albuterol evoked higher ( p < 0.05 ) KE-KF strength gains at multiple velocities versus placebo dosing . A higher lean body mass trend also occurred with albuterol from weeks 10–13 . Results suggest that albuterol augments REX to provide greater strength gains from hypertrophic factors than an REX-placebo assignment The present r and omized , double-blind placebo-controlled study aim ed at investigating the possible improvement in endurance performance caused by inhaled salmeterol ( long-acting beta 2-agonist ) and salbutamol ( short-acting ) compared to placebo in 18 healthy well-trained athletes , aged 17 - 30 years old .  Lung function ( flow-volume loops ) was measured before and after each inhaled study drug and after run to exhaustion . After inhalation of study drug and 10 min warm-up , anaerobic threshold was measured ; thereafter maximum oxygen uptake , peak ventilation and running time until exhaustion during a brief grade d exercise were measured . No significant differences were found for ventilation , oxygen uptake or heart rate at anaerobic threshold or at maximum performance between placebo and the beta 2-agonists . Lung function increased significantly after exercise , but without differences between the beta 2-agonists and placebo . Running time till exhaustion was significantly reduced after both the long- and the short-acting beta 2-agonist compared to the placebo Beta(2)-adrenergic agonists are important therapeutic agents for the prevention and treatment of ( exercise-induced ) asthma in athletes , but may have ergogenic effects . In this study we investigated whether inhalation of a supra-therapeutic dose of 800 microg salbutamol before exercise affects endurance performance during a cycling trial in non-asthmatic athletes . In a double-blind , r and omized cross-over study , 16 athletes performed two trials , where they had to perform a certain amount of work as fast as possible on a cycle ergometer , 30 minutes after inhalation of 800 micro g salbutamol or placebo .  Peak expiratory flow ( PEF ) , forced vital capacity ( FVC ) , and forced expiratory volume in 1 second ( FEV(1 ) ) were measured before and after exercise and blood sample s were obtained before and during exercise . Cycling performance time was 4010.2 + /- 327.7 s after placebo inhalation and 3927.6 + /- 231.3 s after inhalation salbutamol ( p < 0.05 ) . Although salbutamol inhalation increased plasma free fatty acids , glycerol and lactate concentrations and decreased plasma potassium concentrations at rest , no differences between placebo and salbutamol in these variables were found during exercise . PEF and FEV(1 ) were increased after salbutamol inhalation at rest compared with placebo , but the difference between placebo and salbutamol after exercise was no longer significant . Inhalation of a supratherapeutic dose of 800 micro g salbutamol improved endurance cycling performance by 1.9 + /- 1.8 % in non-asthmatic athletes , which indicates that this route of administration does not exclude the possibility of an ergogenic effect of beta(2)-adrenergic agents in athletes . The increase in performance was not explained by changes in plasma concentrations of free fatty acids , glycerol , lactate , and potassium during exercise or by changes in ventilatory parameters at rest and after exercise . Therefore , the mechanism of the increase in performance remains to be determined We investigated the effects of intravenously administered aminophylline ( A ; 6 mg/kg over 20 min , followed by 0.9 mg/kg/h ) , salbutamol ( S ; 4 micrograms/kg over 20 min , followed by 3 micrograms/kg/h ) and placebo ( P ; saline solution ) on the strength of the respiratory muscles , the ventilatory endurance and the exercise tolerance in 7 healthy humans . Neither A nor S caused bronchodilation , as shown by the lack of change in FEV1 . The strength of respiratory muscles , as measured by maximal inspiratory pressure ( MIP ) , and the ventilatory endurance , as measured by sustainable inspiratory pressure ( SIP ) , were not statistically different after A ( MIP : 136.5 + /- SE 11.6 cm H2O ; SIP : 104.2 + /- 8.4 cm H2O or after S ( MIP : 135.7 + /- 11.5 ; SIP : 107.1 + /- 10.4 ) compared to after P ( MIP : 127.1 + /- 10.1 ; SIP : 105.0 + /- 5.9 ) . Significant changes in 12-min walking distance , perceived exertion rate , anaerobic threshold , maximal work output , maximal O2 uptake were observed neither after A nor after S. The exchange ratio and heart rate were higher after A and S than after P at some steps of a progressive , symptom-limited , treadmill-based exercise test . This might be the result of metabolic or cardiovascular adaptations elicited by these drugs . We conclude that A or S at therapeutic concentrations have no clinical ly relevant beneficial effects on ventilatory muscle function and exercise tolerance in healthy subjects The acute effects of inhaled albuterol , a selective beta-2 adrenergic agonist , on measures of endurance cycling performance and pulmonary function were assessed in 21 competitive road cyclists . A 5 step methacholine challenge revealed all cyclists to be non-asthmatic .  Albuterol ( A ) total dose 360 micrograms or a saline placebo ( P ) was administered by inhaler , in 4 metered doses of 90 micrograms each , 15 minutes before cycle ergometry exercise . Heart rate , whole blood lactate , perceived exertion and VO2 were determined at the submaximal workloads of 150 , 200 , 225 , 250 , 275 , 300 watts and at max . Pulmonary function tests determining forced vital capacity , forced expiratory volume during the first second of expiration , forced mid-expiratory flow and maximal voluntary ventilation were performed prior to and 10 minutes after inhalation ; and 5 , 10 and 15 minutes after termination of the exercise protocol . Heart rate was significantly greater during the A compared to the P treatment at 200 ( 150.8 + /- 2.5 vs 146.7 + /- 2.8 beats per minute ) , 225 ( 159.7 + /- 2.4 vs 154.6 + /- 2.7 beats per minute ) and 250 watts ( 166.9 + /- 2.4 vs 164.4 + /- 2.6 beats per minute ) . Whole blood lactate was significantly greater during the A compared to the P treatment at 275 watts ( 4.7 + /- 0.3 vs 4.2 + /- 0.4 mmol.l-1 ) . No other significant differences were found between the 2 treatments at any time point . These data indicate that the acute effect of albuterol inhalation at twice the recommended dosage has no positive effect on endurance performance measures or pulmonary function in athletes who are not asthmatic The use of bronchodilators in athletic competition has allowed asthmatics to participate successfully in competitive events . Little information exists regarding possible bronchodilator use by non-asthmatic competitive athletes . Fifteen non-asthmatic cyclists participated in a double-blind , r and omized , cross-over protocol involving a simulated race , i.e. , one-hour heavy continuous exercise ( minute ventilation ( VE ) 81 L/min BTPS ) followed by maximal effort workload to exhaustion , with/without prior inhalation of albuterol to see if their exercise performance would be acutely altered . Each study day metabolic parameters were obtained four times . Pulmonary function tests were performed prior to and after the inhalant ( albuterol/placebo ) and following exercise . There was a significant increase in forced expiratory flow parameters following albuterol . Although not significant , oxygen uptake ( VO2 ) and VE were smaller during the one-hour submaximal test following albuterol and VO2max and VEmax were higher . There was an increased ride time ( 196 vs. 159 s ; p less than 0.05 ) . Albuterol may provide a competitive advantage for non-asthmatic athletes who might use it To investigate the impact of acute salbutamol intake on performance and selected hormonal and metabolic variables during supramaximal exercise , 13 recreational male athletes performed two 30-second Wingate tests after either placebo ( PLA , lactose ) or salbutamol ( SAL , 4 mg ) oral administration , according to a double-blind and r and omized protocol . Blood sample s collected at rest , end of the Wingate test , recovery ( 5 , 10 , 15 min ) were tested for growth hormone ( GH ) , insulin ( INS ) , blood glucose ( GLU ) , and lactate determination . We found the peak and mean power performed significantly increased after SAL vs. PLA ( PPSAL : 896 + /- 46 ; PPPLA : 819 + /- 57 W ; MPSAL : 585 + /- 27 ; MPPLA : 534 + /- 35 W , p < 0.05 ) , whereas no change was observed in the fatigue index . Blood glucose and INS were significantly increased by SAL at rest , at the end of the Wingate test , and during the 5 first minutes of recovery ( p < 0.05 ) . Plasma GH was significantly decreased by SAL ( p < 0.05 ) during the recovery whereas end-exercise and recovery blood lactate tended but were not significantly increased after SAL vs. PLA . From these data , acute salbutamol intake at therapeutical dosage did appear to improve peak power and mean power during a supramaximal exercise , but the mechanisms involved need further investigation Salbutamol is a widely used drug among elite athletes . We wanted to provide more information on the effects of salbutamol in nonasthmatic athletes . Seventeen highly conditioned male athletes ( VO2max > 70 ml.kg-1.min-1 ) participated in a r and omized , double-blind and placebo-controlled cross-over study . Nebulized salbutamol ( 0.05 mg/kg ) or placebo was inhaled prior to a high intensity ( 110 % of VO2max ) treadmill run to exhaustion . The measured variables included endurance time , oxygen uptake , ventilation , breathing rate , heart rate , and oxygen saturation . Lung function was measured as forced expiratory volume in the first second ( FEV1 ) before and after medication , and during the recovery from the run . The high intensity runs led to total exhaustion after 4 - 10 min . A close-to-significant shortening in endurance time was found when salbutamol was given . During the running ( 0 - 4 min ) the oxygen uptake was slightly lower and the heart rate was slightly higher when salbutamol was given . No differences were found in peak oxygen uptake , peak heart rate , ventilation , breathing rate or oxygen saturation . FEV1 reflected an increase in airway caliber after the inhalation of salbutamol . These changes were still present in the recovery from the test run with the exception of the measurement immediately after the exercise . Although evidence for beta-adrenergic stimulation was found , it was concluded that a therapeutic dose of nebulized salbutamol does not improve performance in highly trained athletes during a high-intensity run to exhaustion 1 . beta 2-Adrenoceptor agonists have been shown to increase rapidly lean body mass and reverse muscle wasting in several animal models of human illness . However , no published information is available for humans . In the present study , we investigated the effects of a slow-release preparation of salbutamol or a placebo on skeletal muscle functional capacity in 12 healthy men . The strength of different muscle groups was measured on two occasions before and after 14 and 21 days of treatment . 2 . No significant changes in muscle strength were observed with placebo during the trial . In contrast , the strength of both quadriceps muscles increased significantly ( 12 + /- 3 % ) after 14 days on salbutamol , and remained elevated at 21 days . Whereas the strength of the hamstring muscles of the dominant leg significantly increased after 21 days on salbutamol ( 22 + /- 6 % ) , the strength of the non-dominant hamstring muscles returned to baseline values . 3 . There was no significant change in the grip strength of either h and in these subjects during the trial . The maximal static inspiratory mouth pressure increased significantly ( 7 + /- 2 % ) after 14 days on salbutamol , and increased further after 21 days ( 15 + /- 4 % ) ; the expiratory mouth pressure remained constant . No significant changes in body weight , skinfold thickness 
    Output:
    
agent
***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: Subjects performed isoload variable resistance exercise ( REX ) 3 days per week . After 10 weeks , they received a double-blind albuterol ( n = 11 ) or placebo ( n = 11 ) capsule assignment with no crossover and continued training . During the first week of capsule administration , dosages were increased from 4 mg to 16 mg daily and then maintained for 14 days . At weeks 0 , 10 , and 13 , we measured upper arm and thigh cross-sectional area , knee and elbow extensor and flexor ( KE , KF , EE , EF ) strength at 3 angular velocities , and lean body mass . Data after 10 weeks showed insignificant between-group differences . From weeks 10–13 , as subjects continued REX training , albuterol evoked higher ( p < 0.05 ) KE-KF strength gains at multiple velocities versus placebo dosing . A higher lean body mass trend also occurred with albuterol from weeks 10–13 . Results suggest that albuterol augments REX to provide greater strength gains from hypertrophic factors than an REX-placebo assignment The present r and omized , double-blind placebo-controlled study aim ed at investigating the possible improvement in endurance performance caused by inhaled salmeterol ( long-acting beta 2-agonist ) and salbutamol ( short-acting ) compared to placebo in 18 healthy well-trained athletes , aged 17 - 30 years old .  Lung function ( flow-volume loops ) was measured before and after each inhaled study drug and after run to exhaustion . After inhalation of study drug and 10 min warm-up , anaerobic threshold was measured ; thereafter maximum oxygen uptake , peak ventilation and running time until exhaustion during a brief grade d exercise were measured . No significant differences were found for ventilation , oxygen uptake or heart rate at anaerobic threshold or at maximum performance between placebo and the beta 2-agonists . Lung function increased significantly after exercise , but without differences between the beta 2-agonists and placebo . Running time till exhaustion was significantly reduced after both the long- and the short-acting beta 2-agonist compared to the placebo Beta(2)-adrenergic agonists are important therapeutic agents for the prevention and treatment of ( exercise-induced ) asthma in athletes , but may have ergogenic effects . In this study we investigated whether inhalation of a supra-therapeutic dose of 800 microg salbutamol before exercise affects endurance performance during a cycling trial in non-asthmatic athletes . In a double-blind , r and omized cross-over study , 16 athletes performed two trials , where they had to perform a certain amount of work as fast as possible on a cycle ergometer , 30 minutes after inhalation of 800 micro g salbutamol or placebo .  Peak expiratory flow ( PEF ) , forced vital capacity ( FVC ) , and forced expiratory volume in 1 second ( FEV(1 ) ) were measured before and after exercise and blood sample s were obtained before and during exercise . Cycling performance time was 4010.2 + /- 327.7 s after placebo inhalation and 3927.6 + /- 231.3 s after inhalation salbutamol ( p < 0.05 ) . Although salbutamol inhalation increased plasma free fatty acids , glycerol and lactate concentrations and decreased plasma potassium concentrations at rest , no differences between placebo and salbutamol in these variables were found during exercise . PEF and FEV(1 ) were increased after salbutamol inhalation at rest compared with placebo , but the difference between placebo and salbutamol after exercise was no longer significant . Inhalation of a supratherapeutic dose of 800 micro g salbutamol improved endurance cycling performance by 1.9 + /- 1.8 % in non-asthmatic athletes , which indicates that this route of administration does not exclude the possibility of an ergogenic effect of beta(2)-adrenergic agents in athletes . The increase in performance was not explained by changes in plasma concentrations of free fatty acids , glycerol , lactate , and potassium during exercise or by changes in ventilatory parameters at rest and after exercise . Therefore , the mechanism of the increase in performance remains to be determined We investigated the effects of intravenously administered aminophylline ( A ; 6 mg/kg over 20 min , followed by 0.9 mg/kg/h ) , salbutamol ( S ; 4 micrograms/kg over 20 min , followed by 3 micrograms/kg/h ) and placebo ( P ; saline solution ) on the strength of the respiratory muscles , the ventilatory endurance and the exercise tolerance in 7 healthy humans . Neither A nor S caused bronchodilation , as shown by the lack of change in FEV1 . The strength of respiratory muscles , as measured by maximal inspiratory pressure ( MIP ) , and the ventilatory endurance , as measured by sustainable inspiratory pressure ( SIP ) , were not statistically different after A ( MIP : 136.5 + /- SE 11.6 cm H2O ; SIP : 104.2 + /- 8.4 cm H2O or after S ( MIP : 135.7 + /- 11.5 ; SIP : 107.1 + /- 10.4 ) compared to after P ( MIP : 127.1 + /- 10.1 ; SIP : 105.0 + /- 5.9 ) . Significant changes in 12-min walking distance , perceived exertion rate , anaerobic threshold , maximal work output , maximal O2 uptake were observed neither after A nor after S. The exchange ratio and heart rate were higher after A and S than after P at some steps of a progressive , symptom-limited , treadmill-based exercise test . This might be the result of metabolic or cardiovascular adaptations elicited by these drugs . We conclude that A or S at therapeutic concentrations have no clinical ly relevant beneficial effects on ventilatory muscle function and exercise tolerance in healthy subjects The acute effects of inhaled albuterol , a selective beta-2 adrenergic agonist , on measures of endurance cycling performance and pulmonary function were assessed in 21 competitive road cyclists . A 5 step methacholine challenge revealed all cyclists to be non-asthmatic .  Albuterol ( A ) total dose 360 micrograms or a saline placebo ( P ) was administered by inhaler , in 4 metered doses of 90 micrograms each , 15 minutes before cycle ergometry exercise . Heart rate , whole blood lactate , perceived exertion and VO2 were determined at the submaximal workloads of 150 , 200 , 225 , 250 , 275 , 300 watts and at max . Pulmonary function tests determining forced vital capacity , forced expiratory volume during the first second of expiration , forced mid-expiratory flow and maximal voluntary ventilation were performed prior to and 10 minutes after inhalation ; and 5 , 10 and 15 minutes after termination of the exercise protocol . Heart rate was significantly greater during the A compared to the P treatment at 200 ( 150.8 + /- 2.5 vs 146.7 + /- 2.8 beats per minute ) , 225 ( 159.7 + /- 2.4 vs 154.6 + /- 2.7 beats per minute ) and 250 watts ( 166.9 + /- 2.4 vs 164.4 + /- 2.6 beats per minute ) . Whole blood lactate was significantly greater during the A compared to the P treatment at 275 watts ( 4.7 + /- 0.3 vs 4.2 + /- 0.4 mmol.l-1 ) . No other significant differences were found between the 2 treatments at any time point . These data indicate that the acute effect of albuterol inhalation at twice the recommended dosage has no positive effect on endurance performance measures or pulmonary function in athletes who are not asthmatic The use of bronchodilators in athletic competition has allowed asthmatics to participate successfully in competitive events . Little information exists regarding possible bronchodilator use by non-asthmatic competitive athletes . Fifteen non-asthmatic cyclists participated in a double-blind , r and omized , cross-over protocol involving a simulated race , i.e. , one-hour heavy continuous exercise ( minute ventilation ( VE ) 81 L/min BTPS ) followed by maximal effort workload to exhaustion , with/without prior inhalation of albuterol to see if their exercise performance would be acutely altered . Each study day metabolic parameters were obtained four times . Pulmonary function tests were performed prior to and after the inhalant ( albuterol/placebo ) and following exercise . There was a significant increase in forced expiratory flow parameters following albuterol . Although not significant , oxygen uptake ( VO2 ) and VE were smaller during the one-hour submaximal test following albuterol and VO2max and VEmax were higher . There was an increased ride time ( 196 vs. 159 s ; p less than 0.05 ) . Albuterol may provide a competitive advantage for non-asthmatic athletes who might use it To investigate the impact of acute salbutamol intake on performance and selected hormonal and metabolic variables during supramaximal exercise , 13 recreational male athletes performed two 30-second Wingate tests after either placebo ( PLA , lactose ) or salbutamol ( SAL , 4 mg ) oral administration , according to a double-blind and r and omized protocol . Blood sample s collected at rest , end of the Wingate test , recovery ( 5 , 10 , 15 min ) were tested for growth hormone ( GH ) , insulin ( INS ) , blood glucose ( GLU ) , and lactate determination . We found the peak and mean power performed significantly increased after SAL vs. PLA ( PPSAL : 896 + /- 46 ; PPPLA : 819 + /- 57 W ; MPSAL : 585 + /- 27 ; MPPLA : 534 + /- 35 W , p < 0.05 ) , whereas no change was observed in the fatigue index . Blood glucose and INS were significantly increased by SAL at rest , at the end of the Wingate test , and during the 5 first minutes of recovery ( p < 0.05 ) . Plasma GH was significantly decreased by SAL ( p < 0.05 ) during the recovery whereas end-exercise and recovery blood lactate tended but were not significantly increased after SAL vs. PLA . From these data , acute salbutamol intake at therapeutical dosage did appear to improve peak power and mean power during a supramaximal exercise , but the mechanisms involved need further investigation Salbutamol is a widely used drug among elite athletes . We wanted to provide more information on the effects of salbutamol in nonasthmatic athletes . Seventeen highly conditioned male athletes ( VO2max > 70 ml.kg-1.min-1 ) participated in a r and omized , double-blind and placebo-controlled cross-over study . Nebulized salbutamol ( 0.05 mg/kg ) or placebo was inhaled prior to a high intensity ( 110 % of VO2max ) treadmill run to exhaustion . The measured variables included endurance time , oxygen uptake , ventilation , breathing rate , heart rate , and oxygen saturation . Lung function was measured as forced expiratory volume in the first second ( FEV1 ) before and after medication , and during the recovery from the run . The high intensity runs led to total exhaustion after 4 - 10 min . A close-to-significant shortening in endurance time was found when salbutamol was given . During the running ( 0 - 4 min ) the oxygen uptake was slightly lower and the heart rate was slightly higher when salbutamol was given . No differences were found in peak oxygen uptake , peak heart rate , ventilation , breathing rate or oxygen saturation . FEV1 reflected an increase in airway caliber after the inhalation of salbutamol . These changes were still present in the recovery from the test run with the exception of the measurement immediately after the exercise . Although evidence for beta-adrenergic stimulation was found , it was concluded that a therapeutic dose of nebulized salbutamol does not improve performance in highly trained athletes during a high-intensity run to exhaustion 1 . beta 2-Adrenoceptor agonists have been shown to increase rapidly lean body mass and reverse muscle wasting in several animal models of human illness . However , no published information is available for humans . In the present study , we investigated the effects of a slow-release preparation of salbutamol or a placebo on skeletal muscle functional capacity in 12 healthy men . The strength of different muscle groups was measured on two occasions before and after 14 and 21 days of treatment . 2 . No significant changes in muscle strength were observed with placebo during the trial . In contrast , the strength of both quadriceps muscles increased significantly ( 12 + /- 3 % ) after 14 days on salbutamol , and remained elevated at 21 days . Whereas the strength of the hamstring muscles of the dominant leg significantly increased after 21 days on salbutamol ( 22 + /- 6 % ) , the strength of the non-dominant hamstring muscles returned to baseline values . 3 . There was no significant change in the grip strength of either h and in these subjects during the trial . The maximal static inspiratory mouth pressure increased significantly ( 7 + /- 2 % ) after 14 days on salbutamol , and increased further after 21 days ( 15 + /- 4 % ) ; the expiratory mouth pressure remained constant . No significant changes in body weight , skinfold thickness 
    Output:
    