***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: OBJECTIVE : To examine the effects of oral creatine ( Cr ) monohydrate supplementation on muscle Cr concentration , body mass , and total body water ( TBW ) , extracellular water ( ECW ) , and intracellular water ( ICW ) volumes . DESIGN AND SETTING : After an overnight fast , urinary Cr and creatinine concentrations , muscle Cr concentration , body mass , TBW , ECW , and ICW were measured , and subjects were r and omly assigned to either a Cr or a placebo ( P ) group . The Cr group ingested 25 g/d of Cr for 7 days ( loading phase ) and 5 g/d for the remaining 21 days ( maintenance phase ) , whereas the P group ingested a sucrose P using the same protocol . All the measures were reassessed immediately after the loading and maintenance phases . SUBJECTS : Sixteen men ( age = 22.8 + /- 3.01 years , height = 179.8 + /- 7.1 cm , body mass = 84.8 + /- 11.2 kg ) and 16 women ( age = 21.8 + /- 2.51 years , height = 163.4 + /- 5.9 cm , body mass = 63.6 + /- 14.0 kg ) involved in resistance training volunteered to participate in this study . MEASUREMENTS : Muscle Cr concentration was determined from the vastus lateralis muscle using a percutaneous needle-biopsy technique . Total body water , ECW , and ICW volumes were assessed using deuterium oxide and sodium bromide dilution analyses . RESULTS : The Cr group experienced a significant increase in muscle Cr concentration , body mass , and TBW . The P group experienced a small but significant increase in TBW only . CONCLUSIONS : The Cr supplementation protocol was effective for increasing muscle Cr concentrations , body mass , and TBW ; however , fluid distribution was not changed Muscle glycogen availability can limit endurance exercise performance . We previously demonstrated 5 days of creatine ( Cr ) and carbohydrate ( CHO ) ingestion augmented post-exercise muscle glycogen storage compared to CHO feeding alone in healthy volunteers . Here , we aim ed to characterise the time-course of this Cr-induced response under more stringent and controlled experimental conditions and identify potential mechanisms underpinning this phenomenon . Fourteen healthy , male volunteers cycled to exhaustion at 70 % VO2peak . Muscle biopsies were obtained at rest immediately post-exercise and after 1 , 3 and 6 days of recovery , during which Cr or placebo supplements ( 20 g day−1 ) were ingested along with a prescribed high CHO diet ( 37.5 kcal kg body mass−1 day−1 , > 80 % calories CHO ) . Oral-glucose tolerance tests ( oral-GTT ) were performed pre-exercise and after 1 , 3 and 6 days of Cr and placebo supplementation . Exercise depleted muscle glycogen content to the same extent in both treatment groups . Creatine supplementation  increased muscle total-Cr , free-Cr and phosphocreatine ( PCr ) content  above placebo following 1 , 3 and 6 days of supplementation ( all P < 0.05 ) . Creatine supplementation also increased muscle glycogen content noticeably above placebo after 1 day of supplementation ( P < 0.05 ) , which was sustained thereafter . This study confirmed dietary Cr augments post-exercise muscle glycogen super-compensation , and demonstrates this occurred during the initial 24 h of post-exercise recovery ( when muscle total-Cr had increased by < 10 % ) . This marked response ensued without apparent treatment differences in muscle insulin sensitivity ( oral-GTT , muscle GLUT4 mRNA ) , osmotic stress ( muscle c-fos and HSP72 mRNA ) or muscle cell volume ( muscle water content ) responses , such that another mechanism must be causative This study was a r and omised , double-blind , placebo-controlled cross-over trial examining the effects of β-hydroxy β-methylbutyrate free acid ( HMB-FA ) supplementation on muscle protein breakdown , cortisol , testosterone and resting energy expenditure ( REE ) during acute fasting . Conditions consisted of supplementation with 3 g/d HMB-FA or placebo during a 3-d meat-free diet followed by a 24-h fast . Urine was collected before and during the 24-h fast for analysis of 3-methylhistidine : creatinine ratio ( 3MH : CR ) . Salivary cortisol , testosterone , their ratio ( T : C ) , and the cortisol awakening response were assessed . ANOVA was used to analyse all dependent variables , and linear mixed models were used to confirm the absence of carryover effects . Eleven participants ( six females , five males ) completed the study . Urinary HMB concentrations confirmed compliance with supplementation . 3MH : CR was unaffected by fasting and supplementation , but the cortisol awakening response differed between conditions . In both conditions , cortisol increased from awakening to 30 min post-awakening ( P=0·01 ) . Cortisol was reduced from 30 to 45 min post-awakening with HMB-FA ( -32 % , d=-1·0 , P=0·04 ) , but not placebo ( PL ) ( -6 % , d=-0·2 , P=0·14 ) . In males , T : C increased from 0 to 24 h of fasting with HMB-FA ( + 162 % , d=3·0 , P=0·001 ) , but not placebo ( + 13 % , d=0·4 , P=0·60 ) , due to reductions in cortisol . REE was higher at 24 h of fasting than 16 h of fasting independent of supplementation ( + 4·0 % , d=0·3 , P=0·04 ) . In conclusion , HMB-FA may affect cortisol responses , but not myofibrillar proteolysis , during acute 24-h fasting The aim of this study was to verify the effect of beta-hydroxy-beta-methylbutyrate ( HMB ) supplementation on physical capacity , body composition and the value of biochemical parameters in highly-trained combat sports athletes . Forty-two males highly-trained in combat sports were subjected to 12 weeks of supplementation with HMB and a placebo in a r and omized , placebo controlled , double-blind crossover manner . Over the course of the experiment , aerobic and anaerobic capacity was determined , while analyses were conducted on body composition and levels of creatine kinase , lactate dehydrogenase , testosterone , cortisol and lactate . Following HMB supplementation , fat-free mass increased ( p = 0.049 ) with a simultaneous reduction of fat mass ( p = 0.016 ) in comparison to placebo . In turn , after HMB supplementation , the following indicators increased significantly in comparison to the placebo : the time to reach ventilatory threshold ( p < 0.0001 ) , threshold load ( p = 0.017 ) and the threshold HR ( p < 0.0001 ) , as well as anaerobic peak power ( p = 0.005 ) , average power ( p = 0.029 ) , maximum speed ( p < 0.001 ) and post-exercise lactate concentrations ( p < 0.0001 ) . However , when compared to the placebo , no differences were observed in blood marker levels . The results indicate that supplying HMB promotes advantageous changes in body composition and stimulates an increase in aerobic and anaerobic capacity in combat sports athletes Background Eccentric exercise-induced damage leads to reductions in muscle force , increased soreness , and impaired muscle function . Creatine monohydrate 's ( Cr ) ergogenic potential is well established ; however few studies have directly examined the effects of Cr supplementation on recovery after damage . We examined the effects of Cr supplementation on muscle proteins and force recovery after eccentrically-induced muscle damage in healthy individuals . Methods Fourteen untrained male participants ( 22.1 ± 2.3 yrs , 173 ± 7.7 cm , 76.2 ± 9.3 kg ) were r and omly separated into 2 supplement groups : i ) Cr and carbohydrate ( Cr-CHO ; n = 7 ) ; or ii ) carbohydrate ( CHO ; n = 7 ) . Participants consumed their supplement for a period of 5 days prior to , and 14 days following a resistance exercise session . Participants performed 4 sets of 10 eccentric-only repetitions at 120 % of their maximum concentric 1-RM on the leg press , leg extension and leg flexion exercise machine . Plasma creatine kinase ( CK ) and lactate dehydrogenase ( LDH ) activity were assessed as relevant blood markers of muscle damage . Muscle strength was examined by voluntary isokinetic knee extension using a Cybex dynamometer . Data were analyzed using repeated measures ANOVA with an alpha of 0.05 . Results The Cr-supplemented group had significantly greater isokinetic ( 10 % higher ) and isometric ( 21 % higher ) knee extension strength during recovery from exercise-induced muscle damage . Furthermore , plasma CK activity was significantly lower ( by an average of 84 % ) after 48 hrs ( P < 0.01 ) , 72 hrs ( P < 0.001 ) , 96 hrs ( P < 0.0001 ) , and 7 days ( P < 0.001 ) recovery in the Cr-supplemented group . Conclusion The major finding of this investigation was a significant improvement in the rate of recovery of knee extensor muscle function  after Cr supplementation following injury Abstract Introduction Studies utilizing beta-hydroxy-beta-methylbutyrate ( HMB ) supplementation in trained population s are limited . No long-term studies utilizing HMB free acid ( HMB-FA ) have been conducted . Therefore , we investigated the effects of 12 weeks of HMB-FA supplementation on skeletal muscle hypertrophy , body composition , strength , and power in trained individuals . We also determined the effects of HMB-FA on muscle damage and performance during an overreaching cycle . Methods A three-phase double-blind , placebo- and diet-controlled r and omized intervention study was conducted . Phase 1 was an 8-week-periodized resistance-training program ; Phase 2 was a 2-week overreaching cycle ; and Phase 3 was a 2-week taper . Muscle mass , strength , and power were examined at weeks 0 , 4 , 8 , and 12 to assess the chronic effects of HMB-FA ; and assessment of these , as well as cortisol , testosterone , and creatine kinase ( CK ) was performed at weeks 9 and 10 of the overreaching cycle . Results HMB-FA result ed in increased total strength ( bench press , squat , and deadlift combined ) over the 12-week training ( 77.1 ± 18.4 vs. 25.3 ± 22.0 kg , p < 0.001 ) ; a greater increase in vertical jump power ( 991 ± 168 vs. 630 ± 167 W , p < 0.001 ) ; and increased lean body mass gain ( 7.4 ± 4.2 vs. 2.1 ± 6.1 kg , p < 0.001 ) in HMB-FA- and placebo-supplemented groups , respectively . During the overreaching cycle , HMB-FA attenuated increases in CK ( −6 ± 91 vs. 277 ± 229 IU/l , p < 0.001 ) and cortisol ( −0.2 ± 2.9 vs. 4.5 ± 1.7 μg/dl , p < 0.003 ) in the HMB-FA- and placebo-supplemented groups , respectively . Conclusions These results suggest that HMB-FA  enhances hypertrophy , strength , and power following chronic resistance training , and prevents decrements in performance following the overreaching PURPOSE To determine the effects of 28 d of creatine supplementation during training on body composition , strength , sprint performance , and hematological profiles . METHODS In a double-blind and r and omized manner , 25 NCAA division IA football players were matched-paired and assigned to supplement their diet for 28 d during resistance/agility training ( 8 h x wk[-1 ] ) with a Phosphagen HP ( Experimental and Applied Sciences , Golden , CO ) placebo ( P ) containing 99 g x d(-1 ) of glucose , 3 g x d(-1 ) of taurine , 1.1 g x d(-1 ) of disodium phosphate , and 1.2 g x d(-1 ) of potassium phosphate ( P ) or Phosphagen HP containing the P with 15.75 g x d(-1 ) of HPCE pure creatine monohydrate ( HP ) . Before and after supplementation , fasting blood sample s were obtained ; total body weight , total body water , and body composition were determined ; subjects performed a maximal repetition test on the isotonic bench press , squat , and power clean ; and subjects performed a cycle ergometer sprint test ( 12 x 6-s sprints with 30-s rest recovery ) . RESULTS Hematological parameters remained within normal clinical limits for active individuals with no side effects reported . Total body weight significantly increased ( P < 0.05 ) in the HP group ( P 0.85 + /- 2.2 ; HP 2.42 + /- 1.4 kg ) while no differences were observed in the percentage of total body water . DEXA scanned body 
    Output:
    
However , this combination seems to not show positive effects relating to markers of exercise-induced muscle damage and anabolic-catabolic hormones