***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: There is no consensus regarding the effects of mixed antioxidant vitamin C and /or vitamin E supplementation on oxidative stress responses to exercise and restoration of muscle function . Thirty-eight men were r and omly assigned to receive either placebo group ( n = 18 ) or mixed antioxidant ( primarily vitamin C & E ) supplements ( n = 20 ) in a double-blind manner . After 6 weeks , participants performed 90 min of intermittent shuttle-running .  Peak isometric torque of the knee flexors/extensors and range of motion at this joint were determined before and after exercise , with recovery of these variables tracked for up to 168 h post-exercise . Antioxidant supplementation elevated pre-exercise plasma vitamin C ( 93 ± 8 μmol l−1 ) and vitamin E ( 11 ± 3 μmol l−1 ) concentrations relative to baseline ( P < 0.001 ) and the placebo group ( P ≤ 0.02 ) . Exercise reduced peak isometric torque ( i.e. 9–19 % relative to baseline ; P ≤ 0.001 ) , which persisted for the first 48 h of recovery with no difference between treatment groups . In contrast , changes in the urine concentration of F2-isoprostanes responded differently to each treatment ( P = 0.04 ) , with a tendency for higher concentrations after 48 h of recovery in the supplemented group ( 6.2 ± 6.1 vs. 3.7 ± 3.4 ng ml−1 ) . Vitamin C & E supplementation also affected serum cortisol concentrations , with an attenuated increase from baseline to the peak values reached after 1 h of recovery compared with the placebo group ( P = 0.02 ) and serum interleukin-6 concentrations were higher after 1 h of recovery in the antioxidant group ( 11.3 ± 3.4 pg ml−1 ) than the placebo group ( 6.2 ± 3.8 pg ml−1 ; P = 0.05 ) . Combined vitamin C & E supplementation neither reduced markers of oxidative stress or inflammation nor did it facilitate recovery of muscle function after exercise-induced muscle damage ABSTRACT This investigation determined the efficacy of black currant nectar ( BCN ) in reducing symptoms of exercise-induced muscle damage ( EIMD ) . Sixteen college students were r and omly assigned to drink either 16 oz of BCN or a placebo ( PLA ) twice a day for eight consecutive days . A bout of eccentric knee extensions ( 3 × 10 sets @ 115 % of 1RM ) was performed on the fourth day . Outcome measures included muscle soreness ( subjective scale from 0 to 10 ) and blood markers of muscle damage ( creatine kinase , CK ) , inflammation ( interleukin-6 , IL-6 ) , and oxygen radical absorbance capacity ( ORAC ) . Although there were no differences in reported soreness between groups , consumption of BCN  reduced CK levels at both 48 ( PLA = 82.13 % vs. BCN = −6.71 % , p = .042 ) and 96 h post exercise ( PLA = 74.96 % vs. BCN = −12.11 % , p = .030 ) . The change in IL-6 was higher in the PLA group ( PLA = 8.84 % vs. BCN = −6.54 % , p = .023 ) at 24 h post exercise . The change in ORAC levels was higher in the treatment group ( BCN = 2.68 % vs. PLA = −6.02 % , p = .039 ) at 48 h post exercise . Our results demonstrate that consumption of BCN prior to and after a bout of eccentric exercise attenuates muscle damage and inflammation Intensive physical exercise may cause muscular injury and increase oxidative stress . The purpose of this study was to examine the effect of an antioxidant , coenzyme Q10 ( CoQ10 ) , on muscular injury and oxidative stress during exercise training . Eighteen male students , all elite Japanese kendo athletes , were r and omly assigned to either a CoQ10 group ( n 10 ) or a placebo group ( n 8) in a double-blind manner . Subjects in the CoQ10 group took 300 mg CoQ10 per d for 20 d , while subjects in the placebo group took the same dosage of a placebo . All subjects practised kendo 5.5 h per d for 6 d during the experimental period . Blood sample s were taken 2 weeks before , during ( 1 d , 3 d , 5 d ) and 1 week after the training . Serum creatine kinase ( CK ) activity and myoglobin ( Mb ) concentration significantly increased in both groups ( at 3 d and 5 d ) . Serum CK ( at 3 d ) , Mb ( at 3 d ) and lipid peroxide ( at 3 d and 5 d ) of the CoQ10 group were lower than those of the placebo group . The leucocyte counts in the placebo group significantly increased ( at 3 d ) and neutrophils significantly increased in both groups ( at 3 d and 5 d ) . Serum scavenging activity against superoxide anion did not change in either group . These results indicate that CoQ10 supplementation reduced exercise-induced muscular injury in athletes Purpose Polyphenolic curcumin is known to have potent anti-inflammatory effects ; thus the present study investigated the hypothesis that curcumin ingestion would attenuate muscle damage after eccentric exercise . Methods Fourteen untrained young men ( 24 ± 1 years ) performed 50 maximal isokinetic ( 120 ° /s ) eccentric contractions of the elbow flexors of one arm on an isokinetic dynamometer and the same exercise with the other arm 4 weeks later . They took 150 mg of curcumin ( theracurmin ) or placebo ( starch ) orally before and 12 h after each eccentric exercise bout in a r and omised , crossover design . Maximal voluntary contraction ( MVC ) torque of the elbow flexors , range of motion of the elbow joint , upper-arm circumference , muscle soreness , serum creatine kinase ( CK ) activity , and plasma interleukin-6 ( IL-6 ) and tumor necrosis factor-α ( TNF-α ) concentration were measured before , immediately after , and 24 , 48 , 72 and 96 h after each eccentric exercise . Changes in these variables over time were compared between curcumin and placebo conditions by two-way repeated measures ANOVA . Results MVC torque decreased smaller and recovered faster ( e.g. , 4 days post-exercise : −31 ± 13 % vs. −15 ± 15 % ) , and peak serum CK activity was smaller ( peak : 7684 ± 8959 IU/L vs. 3398 ± 3562 IU/L ) for curcumin than placebo condition ( P < 0.05 ) . However , no significant differences between conditions were evident for other variables , and no significant changes in IL-6 and TNF-α were evident after exercise . Conclusion It is concluded that theracurmin ingestion attenuates some aspects of muscle damage such as MVC loss and CK activity increase Summary This study investigated the effects of antioxidant vitamin supplementation upon muscle contractile function following eccentric exercise and was performed double blind . Twenty-four physically active young subjects ingested either placebo ( 400 mg ; n = 8) , vitamin E ( 400 mg ; n=8 ) or vitamin C ( 400 mg ; n = 8) for 21 days prior to and for 7 days after performing 60 min of box-stepping exercise .  Contractile function of the triceps surae was assessed by the measurement of maximal voluntary contraction ( MVC ) and the ratio of the force generated at 20 Hz and 50 Hz tetanic stimulation before and after eccentric exercise and for 7 days during recovery . Following eccentric exercise , MVC decreased to 75 ( 4 ) % [ mean ( SE ) ; n = 24 ; P < 0.05 ] of the preexercise values and the 20/50 Hz ratio of tetanic tension from 0.76 ( 0.01 ) to 0.49 ( 0.03 ) [ mean ( SE ) ; n = 24 ; P<0.05 ) . Compared to the placebo group no significant changes in MVC were observed immediately post-exercise , though recovery of MVC in the first 24 h post-exercise was greater in the group supplemented with vitamin C. The decrease in 20/50 Hz ratio of tetanic tension was significantly less ( P < 0.05 ) post-exercise and in the initial phase of recovery in subjects supplemented with vitamin C but not with vitamin E. These data suggest that prior vitamin C supplementation may exert a protective effect against eccentric exercise-induced muscle damage The aim of this study was to investigate whether post-exercise vitamin C supplementation influences recovery from an unaccustomed bout of exercise . Sixteen male subjects were allocated to either a placebo ( P ; n=8 ) or vitamin C ( VC ) group ( n=8 ) . Subjects performed a prolonged ( 90-min ) intermittent shuttle-running test , and supplementation began after the cessation of exercise . Immediately after exercise the VC group consumed 200 mg of VC dissolved in a 500 ml drink , whereas the subjects in the P group consumed the drink alone . Later on the same day and then in the morning and evening of the following 2 days , subjects consumed additional identical drinks . Plasma VC concentrations in the VC group increased above those in the P group 1 h after exercise and remained above P values for the 3 days after exercise . Nevertheless , post-exercise VC supplementation was not associated with improved recovery . Post-exercise serum creatine kinase activities and myoglobin concentrations were unaffected by supplementation . Muscle soreness and the recovery of muscle function in the leg flexors and extensors were not different in VC and P groups . Furthermore , although plasma concentrations of interleukin-6 and malondialdehyde increased following exercise , there was no difference between VC and P groups . These results suggest that either free radicals are not involved in delaying the recovery process following a bout of unaccustomed exercise , or that the consumption of VC wholly after exercise is unable to deliver this antioxidant to the appropriate sites with sufficient expediency to improve recovery PURPOSE Fourteen male cyclists were studied to compare the effect of carbohydrate-protein-antioxidant beverage ( CHOPA ) to an isocaloric carbohydrate-only ( CHO ) beverage on time to fatigue and muscle damage . METHODS Subjects performed two sets of rides to exhaustion on a cycle ergometer . In each set , the first ride was performed at 70 % VO2peak , and the second was performed 24 h later at 80 % . CHO or CHOPA was consumed every 15 min during exercise and immediately afterward . Plasma CK and LDH and muscle soreness were measured pre- and postexercise . RESULTS Time to fatigue was not different between CHO and CHOPA at 70 % VO2peak ( 95.8 + /- 29.7 vs 98.1 + /- 28.7 min ) , 80 % VO2peak ( 42.3 + /- 18.6 vs 42.9 + /- 21.8 min ) , or total performance time ( 138.1 + /- 39.3 vs 140.9 + /- 43.7 min ) . Postexercise CK was increased ( P < 0.05 ) from baseline in CHO ( 203 + /- 120 vs 582 + /- 475 U.L(-1 ) ) but not with CHOPA ( 188 + /- 119 vs 273 + /- 169 U.L(-1 ) ) . Similarly , LDH values increased over baseline in CHO ( 437 + /- 46 vs 495 + /- 64 U.L(-1 ) ) but not with CHOPA ( 432 + /- 40 vs 451 + /- 43 U.L(-1 ) ) . Postexercise CPK and LDH were higher after the CHO trial than after the CHOPA trial . Median postexercise muscle soreness was higher in CHO ( 3.0 + /- 5.0 ) than with CHOPA ( 1.0 + /- 3.0 ) . CONCLUSION No differences in time to fatigue were observed between the beverages , despite lower total carbohydrate content in the CHOPA beverage . The CHOPA beverage attenuated postexercise muscle damage , as evidence d by CK and LDH values , compared with an isocaloric CHO beverage PURPOSE Dietary supplementation with polyphenols , particularly ellagitannins , may attenuate the muscular damage experienced after eccentric exercise , producing delayed-onset muscle soreness . The purpose of this study was to determine whether ellagitannin supplementation from Wonderful variety pomegranate extract ( POMx ) improved recovery of skeletal muscle strength after eccentric exercise . METHODS Recreationally active males were r and omized into a crossover design with either pomegranate extract ( POMx ) or placebo ( PLA ) , each given during a period of 9 d . To produce delayed-onset muscle soreness , subjects performed two sets of 20 maximal eccentric elbow flexion exercises with one arm . Maximal isometric elbow flexion strength and muscle soreness as well as serum measures of creatine kinase , myoglobin , interleukin 
    Output:
    
AUTHORS ' CONCLUSIONS There is moderate to low- quality evidence that high dose antioxidant supplementation does not result in a clinical ly relevant reduction of muscle soreness after exercise at up to 6 hours or at 24 , 48 , 72 and 96 hours after exercise .
There is no evidence available on subjective recovery and only limited evidence on the adverse effects of taking antioxidant supplements .