title: Sodium bicarbonate intake improves high-intensity intermittent exercise performance in trained young men.
abstract: BACKGROUND
  Sodium bicarbonate intake has been shown to improve exercise tolerance, but the effects on high-intensity intermittent exercise are less clear. Thus, the aim of the present study was to determine the effect of sodium bicarbonate intake on Yo-Yo intermittent recovery test level 2 performance in trained young men.
  
  
  METHODS
  Thirteen men aged 23 ± 1 year (height: 180 ± 2 cm, weight: 78 ± 3 kg; VO2max: 61.3 ± 3.3 mlO2 · kg(-1) · min(-1); means ± SEM) performed the Yo-Yo intermittent recovery test level 2 (Yo-Yo IR2) on two separate occasions in randomized order with (SBC) and without (CON) prior intake of sodium bicarbonate (0.4 g · kg(-1) body weight). Heart rate and rating of perceived exertion (RPE) were measured during the test and venous blood samples were taken frequently.
  
  
  RESULTS
  Yo-Yo IR2 performance was 14 % higher (P = 0.04) in SBC than in CON (735 ± 61 vs 646 ± 46 m, respectively). Blood pH and bicarbonate were similar between trials at baseline, but higher (P = 0.003) immediately prior to the Yo-Yo IR2 test in SBC than in CON (7.44 ± 0.01 vs 7.32 ± 0.01 and 33.7 ± 3.2 vs 27.3 ± 0.6 mmol · l(-1), respectively). Blood lactate was 0.9 ± 0.1 and 0.8 ± 0.1 mmol · l(-1) at baseline and increased to 11.3 ± 1.4 and 9.4 ± 0.8 mmol · l(-1) at exhaustion in SBC and CON, respectively, being higher (P = 0.03) in SBC. Additionally, peak blood lactate was higher (P = 0.02) in SBC than in CON (11.7 ± 1.2 vs 10.2 ± 0.7 mmol · l(-1)). Blood glucose, plasma K(+) and Na(+) were not different between trials. Peak heart rate reached at exhaustion was 197 ± 3 and 195 ± 3 bpm in SBC and CON, respectively, with no difference between conditions. RPE was 7% lower (P = 0.003) in SBC than in CON after 440 m, but similar at exhaustion (19.3 ± 0.2 and 19.5 ± 0.2).
  
  
  CONCLUSIONS
  In conclusion, high-intensity intermittent exercise performance is improved by prior intake of sodium bicarbonate in trained young men, with concomitant elevations in blood alkalosis and peak blood lactate levels, as well as lowered rating of perceived exertion.
authors.affiliation: Department of Nutrition, Exercise and Sports, Section of Human Physiology, Copenhagen Centre for Team Sport and Health, University of Copenhagen, Copenhagen, Denmark ; Sport and Health Sciences, College of Life and Environmental Sciences, St. Luke's Campus, University of Exeter, Exeter, UK.
authors.forename: Peter
authors.initials: P
authors.lastname: Krustrup
authors.affiliation: Democrite University of Thrace, Komotini, 69100 Greece.
authors.forename: Georgios
authors.initials: G
authors.lastname: Ermidis
authors.affiliation: Faculty of Natural and Health Sciences, University of the Faroe Islands, Jónas Broncks gøta 25. 3rd floor, Tórshavn, Faroe Islands ; Department of Food and Nutrition, and Sport Science, Center of Health and Human Performance, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Magni
authors.initials: M
authors.lastname: Mohr
mesh_terms: D000471:Alkalosis / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight; D018592:Cross-Over Studies; D005221:Fatigue / Q000097:blood / Q000188:drug therapy; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000097:blood; D008297:Male; D010807:Physical Endurance / Q000187:drug effects*; D005082:Physical Exertion / Q000187:drug effects; D011188:Potassium / Q000097:blood; D016037:Single-Blind Method; D012964:Sodium / Q000097:blood; D017693:Sodium Bicarbonate / Q000008:administration & dosage* / Q000097:blood; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D019344:Lactic Acid; D017693:Sodium Bicarbonate; D012964:Sodium; D011188:Potassium
keywords: Blood pH and lactate; Buffer capacity; Fatigue; Plasma potassium; Yo-Yo IR2 performance