***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: Abstract This study investigated the influence of dietary inorganic nitrate ( NO 3 − ) supplementation on pulmonary O2 uptake ( V˙O2 ) and muscle deoxyhemoglobin/myoglobin ( i.e. deoxy [ Hb + Mb ] ) kinetics during submaximal cycling exercise . In a r and omized , placebo‐controlled , cross‐over study , eight healthy and physically active male subjects completed two step cycle tests at a work rate equivalent to 50 % of the difference between the gas exchange threshold and peak V˙O2 over separate 4‐day supplementation periods with NO 3 −‐rich ( BR ; providing 8.4 mmol NO 3 −∙day−1 ) and NO 3 −‐depleted ( placebo ; PLA ) beetroot juice .  Pulmonary V˙O2 was measured breath‐by‐breath and time‐resolved near‐infrared spectroscopy was utilized to quantify absolute deoxy [ Hb + Mb ] and total [ Hb + Mb ] within the rectus femoris , vastus lateralis , and vastus medialis . There were no significant differences ( P > 0.05 ) in the primary deoxy [ Hb + Mb ] mean response time or amplitude between the PLA and BR trials at each muscle site . BR significantly increased the mean ( three‐site ) end‐exercise deoxy [ Hb + Mb ] ( PLA : 91 ± 9 vs. BR : 95 ± 12 μmol/L , P < 0.05 ) , with a tendency to increase the mean ( three‐site ) area under the curve for total [ Hb + Mb ] responses ( PLA : 3650 ± 1188 vs. BR : 4467 ± 1315 μmol/L sec−1 , P = 0.08 ) . The V˙O2 slow component reduction after BR supplementation ( PLA : 0.27 ± 0.07 vs. BR : 0.23 ± 0.08 L min−1 , P = 0.07 ) correlated inversely with the mean increases in deoxy [ Hb + Mb ] and total [ Hb + Mb ] across the three muscle regions ( r 2 = 0.62 and 0.66 , P < 0.05 ) . Dietary NO 3 − supplementation  increased O2 diffusive conductance across locomotor muscles in association with improved V˙O2 dynamics during heavy‐intensity cycling transitions BACKGROUND Dietary inorganic nitrate ( NO3- ) and its reduced forms nitrite ( NO2- ) and nitric oxide ( NO ) , respectively , are of critical importance for host defense in the oral cavity . High concentrations of salivary nitrate are linked to a lower prevalence of caries due to growth inhibition of cariogenic bacteria . OBJECTIVE In-vitro studies suggest that the formation of antimicrobial NO results in an increase of the pH preventing erosion of tooth enamel . The purpose of this study was to prove this effect in-vivo . METHODS In a r and omized clinical study with 46 subjects we investigated whether NO3- rich beetroot juice exhibits a protective effect against caries by an increase of salivary pH. RESULTS Our results show that , in comparison to a placebo group , consumption of beetroot juice that contains 4000 mg/L NO3- results in elevated levels of salivary NO2- , nitrite NO3- , and NO . Furthermore , we determined an increase of the mean pH of saliva from 7.0 to 7.5 , confirming the anti-cariogenic effect of the used NO3 - -rich beetroot juice . CONCLUSIONS Taken together , we have found that NO3 - -rich beetroot juice holds potential effects against dental caries by preventing acidification of human saliva . TRIAL REGISTRATION C-87 - 15 ( Ethics Commissions of Upper Austria ) It is possible that dietary nitrate ( NO3− ) supplementation may improve both physical and cognitive performance via its influence on blood flow and cellular energetics . Purpose To investigate the effects of dietary NO3− supplementation on exercise performance and cognitive function during a prolonged intermittent sprint test ( IST ) protocol , which was design ed to reflect typical work patterns during team sports . Methods In a double-blind r and omised crossover study , 16 male team-sport players received NO3−-rich ( BR ; 140 mL day−1 ; 12.8 mmol of NO3− ) , and NO3−-depleted ( PL ; 140 mL day−1 ; 0.08 mmol NO3− ) beetroot juice for 7 days . On day 7 of supplementation , subjects completed the IST ( two 40-min “ halves ” of repeated 2-min blocks consisting of a 6-s “ all-out ” sprint , 100-s active recovery and 20 s of rest ) , on a cycle ergometer during which cognitive tasks were simultaneously performed . Results Total work done during the sprints of the IST was greater in BR ( 123 ± 19 kJ ) compared to PL ( 119 ± 17 kJ ; P < 0.05 ) . Reaction time of response to the cognitive tasks in the second half of the IST was improved in BR compared to PL ( BR first half : 820 ± 96 vs. second half : 817 ± 86 ms ; PL first half : 824 ± 114 vs. second half : 847 ± 118 ms ; P < 0.05 ) . There was no difference in response accuracy . Conclusions These findings suggest that dietary NO3−  enhances repeated sprint performance and may attenuate the decline in cognitive function ( and specifically reaction time ) that may occur during prolonged intermittent exercise The beneficial effects of beetroot juice supplementation ( BJS ) have been tested during cycling , walking , and running . The purpose of the present study was to investigate whether BJS can also improve performance in swimmers . Fourteen moderately trained male master swimmers were recruited and underwent two incremental swimming tests r and omly assigned in a pool during which workload , oxygen uptake ( VO2 ) , carbon dioxide production ( VCO2 ) , pulmonary ventilation ( VE ) , and aerobic energy cost ( AEC ) of swimming were measured . One was a control swimming test ( CSW ) and the other a swimming test after six days of BJS ( 0.5l/day organic beetroot juice containing about 5.5 mmol of NO3− ) . Results show that workload at anaerobic threshold was significantly increased by BJS as compared to the CSW test ( 6.3 ± 1 and 6.7 ± 1.1 kg during the CSW and the BJS test respectively ) . Moreover , AEC was significantly reduced during the BJS test ( 1.9 ± 0.5 during the SW test vs. 1.7 ± 0.3 kcal·kg−1·h−1 during the BJS test ) . The other variables lacked a statistically significant effect with BJS . The present investigation provides evidence that BJS positively affects performance of swimmers as it reduces the AEC and increases the workload at anaerobic threshold Nitrate supplementation appears to be most ergogenic when oxygen availability is restricted and subsequently may be particularly beneficial for swimming performance due to the breath-hold element of this sport . This represents the first investigation of nitrate supplementation and swimming time-trial ( TT ) performance . In a r and omized double-blind repeated- measures crossover study , ten ( 5 male , 5 female ) trained swimmers ingested 140ml nitrate-rich ( ~12.5mmol nitrate ) or nitrate-depleted ( ~0.01mmol nitrate ) beetroot juice . Three hours later , subjects completed a maximal effort swim TT comprising 168 m ( 8 × 21 m lengths ) backstroke . Preexercise fractional exhaled nitric oxide concentration was significantly elevated with nitrate compared with placebo , Mean ( SD ) : 17 ( 9 ) vs. 7 (3)p.p.b . , p = .008 . Nitrate supplementation had a likely trivial effect on overall swim TT performance ( mean difference 1.22s ; 90 % CI -0.18 - 2.6s ; 0.93 % ; p = .144 ; d = 0.13 ; unlikely beneficial ( 22.6 % ) , likely trivial ( 77.2 % ) , most unlikely negative ( 0.2 % ) ) . The effects of  nitrate supplementation  during the first half of the TT were trivial ( mean difference 0.29s ; 90 % CI -0.94 - 1.5s ; 0.46 % ; p = .678 ; d = 0.05 ) , but there was a possible beneficial effect of nitrate supplementation during the second half of the TT ( mean difference 0.93s ; 90 % CI 0.13 - 1.70s ; 1.36 % ; p = .062 ; d = 0.24 ; possibly beneficial ( 63.5 % ) , possibly trivial ( 36.3 % ) , most unlikely negative ( 0.2 % ) ) . The duration and speed of underwater swimming within the performance did not differ between nitrate and placebo ( both p > .30 ) . Nitrate supplementation increased nitric oxide bioavailability but did not benefit short-distance swimming performance or the underwater phases of the TT . Further investigation into the effects of nitrate supplementation during the second half of performance tests may be warranted A system has been constructed to evaluate the design , implementation , and analysis of  r and omized control trials ( RCT ) . The degree of quadruple blinding ( the r and omization process , the physicians and patients as to therapy , and the physicians as to ongoing results ) is considered to be the most important aspect of any trial . The analytic techniques are scored with the same emphasis as is placed on the control of bias in the planning and implementation of the studies . Description of the patient and treatment material s and the measurement of various controls of quality have less weight . An index of quality of a RCT is proposed with its pros and cons . If published papers were to approximate these principles , there would be a marked improvement in the quality of r and omized control trials . Finally , a reasonable st and ard design and conduct of trials will facilitate the interpretation of those with conflicting results and help in making valid combinations of undersized trials The influence of dietary nitrate ( NO3- ) supplementation on indices of maximal sprint and intermittent exercise performance is unclear . PURPOSE To investigate the effects of NO3- supplementation on sprint running performance , and cognitive function and exercise performance during the sport-specific Yo-Yo Intermittent Recovery level 1 test ( IR1 ) . METHODS In a double-blind , r and omized , crossover study , 36 male team-sport players received NO3 - -rich ( BR ; 70 mL·day-1 ; 6.4 mmol of NO3- ) , and NO3 - -depleted ( PL ; 70 mL·day-1 ; 0.04 mmol NO3- ) beetroot juice for 5 days . On day 5 of supplementation , subjects completed a series of maximal 20-m sprints followed by the Yo-Yo IR1 . Cognitive tasks were completed prior to , during and immediately following the Yo-Yo IR1 . RESULTS BR improved sprint split times relative to PL at 20 m ( 1.2 % ; BR 3.98 ± 0.18 vs. PL 4.03 ± 0.19 s ; P < 0.05 ) , 10 m ( 1.6 % ; BR 2.53 ± 0.12 vs. PL 2.57 ± 0.19 s ; P < 0.05 ) and 5 m ( 2.3 % ; BR 1.73 ± 0.09 vs. PL 1.77 ± 0.09 s ; P < 0.05 ) . The distance covered in the Yo-Yo IR1 test improved by 3.9 % ( BR 1422 ± 502 vs. PL 1369 ± 505 m ; P < 0.05 ) . The reaction time to the cognitive tasks was shorter in BR ( 615 ± 98 ms ) than PL ( 645 ± 120 ms ; P < 0.05 ) at rest but not during the Yo-Yo IR1 . There was no difference in response accuracy . CONCLUSIONS Dietary NO3- supplementation enhances maximal sprint and high-intensity intermittent running performance in competitive team sport players . Our findings suggest that NO3- supplementation has the potential to improve performance in single-sprint or multiple-sprint ( team ) sports A number of vegetables have a high nitrate content which after ingestion can be reduced to nitrite by oral bacteria , and further to vasoprotective NO endogenously . In the present study , two separate r and omly controlled , single-blind , cross-over , postpr and ial studies were performed in normotensive volunteers . Ambulatory blood pressure ( BP ) was measured over a 24 h period following consumption of either four doses of beetroot juice ( BJ ) , 0 , 100 , 250 and 500 g ( n 18 ) , or three bread products , control bread ( 0 g beetroot ) , red beetroot- and white beetroot-enriched breads ( n 14 ) . Total urinary nitrate/nitrite ( NO(x ) ) was measured at baseline , and at 2 , 4 and 24 h post-ingestion . BJ consumption significantly , and in a near dose-dependent manner , lowered systolic BP ( SBP , P < 0·01 ) and diastolic BP ( DBP , P < 0·001 ) over a period of 
    Output:
    
Drinking BRJ may easily increase nitrate intake above the acceptable daily intake , which is known to stimulate the endogenous formation of N-nitroso compounds ( NOC 's ) , a class of compounds that is known to be carcinogenic and that may also induce several other adverse effects .