god forbid that climbing ever become a regulated olympic sport, but if it were...
http://www.nytimes.com/2009/05/21/sports/21swim.html
..would we be considered "cheaters"?
Buffering Lactic Acid
-
the lurkist
- Posts: 2240
- Joined: Wed Nov 13, 2002 2:07 pm
Pub Med Search- Read if you are bored- Take home- It seems to work.
Items 1 - 16 of 16
One page.
1: Int J Sports Med. 2008 Jul;29(7):545-51. Epub 2007 Nov 14.
Related Articles, Links
Click here to read
Pre-exercise alkalosis and acid-base recovery.
Siegler JC, Keatley S, Midgley AW, Nevill AM, McNaughton LR.
Department of Sport, Health and Exercise Science, University of Hull, Hull, United Kingdom. J.Siegler@hull.ac.uk
The aim of this study was to observe the influence of pre-exercise sodium bicarbonate (NaHCO3) ingestion and varying recovery modes on acid-base recovery from a single bout of supramaximal exercise. Nine male subjects completed four separate, randomized cycle ergometer exercise trials to volitional fatigue at 120% maximum power output, under the following conditions: 0.3 g.kg(-1) BW NaHCO3 ingestion with passive recovery (BICARB P), 0.3 g.kg (-1) BW NaHCO3 ingestion with active recovery (BICARB A), placebo ingestion with passive recovery (PLAC P) and placebo ingestion with active recovery (PLAC A). Capillary blood samples were obtained every minute for 15 min during recovery. Significant main effects for pH were observed for time (F = 42.1, p < 0.001), intervention (BICARB and PLAC) (F = 1117.3, p < 0.001) and recovery condition (F = 150.0, p < 0.001), as the BICARB condition reduced acid-base perturbation. Significant interaction effects were observed between conditions (BICARB and PLAC) for active and passive recovery modes (F = 29.1, p < 0.001) as the active recovery facilitated H+ removal better than the passive condition. Pre-exercise alkalosis attenuates blood acid-base perturbations from supramaximal exercise to exhaustion, regardless of whether the recovery mode is active or passive. These findings suggest that individuals may benefit from introducing a pre-exercise alkalotic condition while including passive recovery during high-intensity training protocols.
Publication Types:
* Randomized Controlled Trial
PMID: 18004683 [PubMed - indexed for MEDLINE]
2: Eur J Appl Physiol. 2007 Nov;101(4):409-17. Epub 2007 Jul 13.
Related Articles, Links
Click here to read
Effect of oral administration of sodium bicarbonate on surface EMG activity during repeated cycling sprints.
Matsuura R, Arimitsu T, Kimura T, Yunoki T, Yano T.
Laboratory of Exercise Physiology, Graduate School of Education, Hokkaido University, Kita-11, Nishi-7, Kita-ku, Sapporo, 060-0811, Japan. dj-ryota@edu.hokudai.ac.jp
The purpose of this study was to determine the effect of oral administration of sodium bicarbonate (NaHCO3) on surface electromyogram (SEMG) activity from the vastus lateralis (VL) during repeated cycling sprints (RCS). Subjects performed two RCS tests (ten 10-s sprints) interspersed with both 30-s and 360-s recovery periods 1 h after oral administration of either NaHCO3 (RCSAlk) or CaCO3 (RCSPla) in a random counterbalanced order. Recovery periods of 360 s were set before the 5th and 9th sprints. The rate of decrease in plasma HCO3- concentration during RCS was significantly greater in RCSAlk than in RCSPla, but the rates of decline in blood pH during the two RCS tests were similar. There was no difference between change in plasma lactate concentration in RCSAlk and that in RCSPla. Performance during RCSAlk was similar to that during RCSPla. There were no differences in oxygen uptake immediately before each cycling sprint (preVO2) and in SEMG activity between RCSAlk and RCSPla. In conclusion, oral administration of NaHCO3 did not affect SEMG activity from the VL. This suggests that the muscle recruitment strategy during RCS is not determined by only intramuscular pH.
Publication Types:
* Randomized Controlled Trial
PMID: 17628824 [PubMed - indexed for MEDLINE]
3: Med Sci Sports Exerc. 2006 Nov;38(11):1909-17.
Related Articles, Links
Click here to read
Sodium bicarbonate ingestion alters the slow but not the fast phase of VO2 kinetics.
Berger NJ, McNaughton LR, Keatley S, Wilkerson DP, Jones AM.
Department of Exercise and Sport Science, Manchester Metropolitan University, Hassall Road, Alsager, UK.
PURPOSE: The influence of metabolic alkalosis (ALK) on pulmonary O2 uptake (pVO2) kinetics during high-intensity cycle exercise is controversial. The purpose of this study was to examine the influence of ALK induced by sodium bicarbonate (NaHCO3) ingestion on pVO2 kinetics, using a sufficient number of repeat-step transitions to provide high confidence in the results obtained. METHODS: Seven healthy males completed step tests to a work rate requiring 80% pVO2max on six separate occasions: three times after ingestion of 0.3 g x kg(-1) body mass NaHCO3 in 1 L of fluid, and three times after ingestion of a placebo (CON). Blood samples were taken to assess changes in acid-base balance, and pVO2 was measured breath-by-breath. RESULTS: NaHCO3 ingestion significantly increased blood pH and [bicarbonate] both before and during exercise relative to the control condition (P < 0.001). The time constant of the phase II pVO2 response was not different between conditions (CON: 29 +/- 6 vs ALK: 32 +/- 7 s; P = 0.21). However, the onset of the pVO2 slow component was delayed by NaHCO3 ingestion (CON: 120 +/- 19 vs ALK: 147 +/- 34 s; P < 0.01), resulting in a significantly reduced end-exercise pVO2 (CON: 2.88 +/- 0.19 vs ALK: 2.79 +/- 0.23 L x min(-1); P < 0.05). CONCLUSIONS: Metabolic alkalosis has no effect on phase II pVO2 kinetics but alters the pVO2 slow-component response, possibly as a result of the effects of NaHCO3 ingestion on muscle pH.
Publication Types:
* Randomized Controlled Trial
PMID: 17095923 [PubMed - indexed for MEDLINE]
4: Eur J Appl Physiol. 2007 Jan;99(2):173-81. Epub 2006 Nov 7.
Related Articles, Links
Click here to read
Potassium kinetics and its relationship with ventilation during repeated bouts of exercise in women.
Zavorsky GS, Gow J, Murias JM.
Department of Anesthesia, McGill University Health Center, Montreal General Hospital, 1650 Cedar Avenue, Room D10-144, H3G 1A4, Montreal, QC, Canada. gerald.zavorsky@mcgill.ca
The purpose of this study was to determine the electrolyte concentration changes in arterial plasma from high-intensity repeated bouts of cycling exercise in well-trained females and to determine the relationships between arterial plasma lactate, potassium (K+), bicarbonate (HCO3(-)), and pH with minute ventilation. Fourteen female subjects (mean age = 27 +/- 4 years; mean height = 170 +/- 7 cm; mean weight = 62 +/- 7 kg; maximal oxygen uptake = 50 +/- 6 ml/kg/min) were recruited to perform 3 x 5 min bouts of exercise at 236 +/- 27 W with 10 min recovery between each set. Minute ventilation, arterial plasma lactate, potassium, calcium, chloride, and sodium ion concentrations were measured a minute 0, 1, 2, 3, 4, 5 of each set and midway through recovery (21 sampling points total per subject). The results showed that the strongest relationship was between arterial plasma K+ concentration and minute ventilation (r2 = 0.91), and, that arterial plasma lactate mirrored both arterial plasma HCO3(-) and pH. In conclusion, this study demonstrates that women exhibit similar electrolyte responses as reported elsewhere in men, and support the idea that K+ may partly contribute to controlling ventilation during high-intensity exercise and recovery.
PMID: 17089156 [PubMed - indexed for MEDLINE]
5: Med Sci Sports Exerc. 2006 Oct;38(10):1746-53.
Related Articles, Links
Click here to read
Dose-related effects of prolonged NaHCO3 ingestion during high-intensity exercise.
Douroudos II, Fatouros IG, Gourgoulis V, Jamurtas AZ, Tsitsios T, Hatzinikolaou A, Margonis K, Mavromatidis K, Taxildaris K.
Democritus University of Thrace, Department of Physical Education & Sport Science, Komotini, Greece.
PURPOSE: Sodium bicarbonate (NaHCO3) ingestion may prevent exercise-induced perturbations in acid-base balance, thus resulting in performance enhancement. This study aimed to determine whether different levels of NaHCO3 intake influences acid-base balance and performance during high-intensity exercise after 5 d of supplementation. METHODS: Twenty-four men (22 +/- 1.7 yr) were randomly assigned to one of three groups (eight subjects per group): control (C, placebo), moderate NaHCO3 intake (MI, 0.3 g x kg(-1) x d(-1)), and high NaHCO3 intake (HI, 0.5 g x kg(-1) x d(-1)). Arterial pH, HCO3(-), PO2, PCO2, K+, Na, base excess (BE), lactate, and mean power (MP) were measured before and after a Wingate test pre- and postsupplementation. RESULTS: HCO3(-) increased proportionately to the dosage level. No differences were detected in C. Supplementation increased MP (W x kg(-)) in MI (7.36 +/- 0.7 vs 6.73 +/- 1.0) and HI (7.72 +/- 0.9 vs 6.69 +/- 0.6), with HI being more effective than MI. NaHCO3 ingestion resulted postexercise in increased lactate (mmol x L(-1)) (12.3 +/- 1.8 vs 10.3 +/- 1.9 and 12.4 +/- 1.2 vs 10.4 +/- 1.5 in MI and HI, respectively), reduced exercise-induced drop of pH (7.305 +/- 0.04 vs 7.198 +/- 0.02 and 7.343 +/- 0.05 vs 7.2 +/- 0.01 in MI and HI, respectively) and HCO3(-) (mmol x L(-1)) (13.1 +/- 2.4 vs 17.5 +/- 2.8 and 13.2 +/- 2.7 vs 19.8 +/- 3.2 for HCO3 in MI and HI, respectively), and reduced K (3.875 +/- 0.2 vs 3.625 +/- 0.3 mmol x L(-1) in MI and HI, respectively). CONCLUSION: NaHCO3 administration for 5 d may prevent acid-base balance disturbances and improve performance during anaerobic exercise in a dose-dependent manner.
Publication Types:
* Clinical Trial
* Randomized Controlled Trial
PMID: 17019296 [PubMed - indexed for MEDLINE]
6: QJM. 2006 Jul;99(7):475-85.
Related Articles, Links
Click here to read
Comment in:
* QJM. 2006 Dec;99(12):881; author reply 881-2.
The patient with a severe degree of metabolic acidosis: a deductive analysis.
Maccari C, Kamel KS, Davids MR, Halperin ML.
Division of Nephrology, St. Michael's Hospital, University of Toronto, Toronto, Ontario, M5B 1A6, Canada.
This teaching exercise demonstrates how principles of physiology might help in identifying the cause of a particularly severe case of metabolic acidosis and making appropriate decisions about therapy. The patient's plasma pH was 7.00 and their plasma bicarbonate concentration was 2 mmol/l. Because the time course of the patient's illness was believed to be <24 h, this suggested that a large quantity of acid had been added to the body in this short time period, but the medical team managing the case could not identify any acid that could have been produced rapidly by endogenous processes, or was ingested by the patient. Moreover, there was a question about how such a very low arterial PCO(2) (8 mmHg) could be sustained. Even once the diagnosis was made, there were issues to resolve concerning therapy. These included questions about how much sodium bicarbonate to administer, and what dangers might arise during this therapy. The missing links in this interesting story emerge during a discussion between the medical team and their imaginary mentor, Professor McCance.
Publication Types:
* Case Reports
PMID: 16835252 [PubMed - indexed for MEDLINE]
7: J Appl Physiol. 2005 Nov;99(5):1668-75. Epub 2005 Jul 7.
Related Articles, Links
Click here to read
NaHCO3-induced alkalosis reduces the phosphocreatine slow component during heavy-intensity forearm exercise.
Forbes SC, Raymer GH, Kowalchuk JM, Marsh GD.
School of Kinesiology, The University of Western Ontario, London, Ontario, Canada N6A-3K7.
During heavy-intensity exercise, the mechanisms responsible for the continued slow decline in phosphocreatine concentration ([PCr]) (PCr slow component) have not been established. In this study, we tested the hypothesis that a reduced intracellular acidosis would result in a greater oxidative flux and, consequently, a reduced magnitude of the PCr slow component. Subjects (n = 10) performed isotonic wrist flexion in a control trial and in an induced alkalosis (Alk) trial (0.3g/kg oral dose of NaHCO3, 90 min before testing). Wrist flexion, at a contraction rate of 0.5 Hz, was performed for 9 min at moderate- (75% of onset of acidosis; intracellular pH threshold) and heavy-intensity (125% intracellular pH threshold) exercise. 31P-magnetic resonance spectroscopy was used to measure intracellular [H+], [PCr], [Pi], and [ATP]. The initial recovery data were used to estimate the rate of ATP synthesis and oxidative flux at the end of heavy-intensity exercise. In repeated trials, venous blood sampling was used to measure plasma [H+], [HCO3-], and [Lac-]. Throughout rest and exercise, plasma [H+] was lower (P < 0.05) and [HCO3-] was elevated (P < 0.05) in Alk compared with control. During the final 3 min of heavy-intensity exercise, Alk caused a lower (P < 0.05) intracellular [H+] [246 (SD 117) vs. 291 nmol/l (SD 129)], a greater (P <0> 0.05) in the conditions at the end of heavy-intensity exercise. In conclusion, our results are consistent with a reduced intracellular acidosis, causing a decrease in the magnitude of the PCr slow component. The decreased PCr slow component in Alk did not appear to be due to an elevated oxidative flux.
Publication Types:
* Clinical Trial
PMID: 16002768 [PubMed - indexed for MEDLINE]
8: Med Sci Sports Exerc. 2005 May;37(5):759-67.
Related Articles, Links
Click here to read
Effects of induced metabolic alkalosis on prolonged intermittent-sprint performance.
Bishop D, Claudius B.
Team Sport Research Group, School of Human Movement and Exercise Science, The University of Western Australia, Crawley, WA, Australia. dbishop@cyllene.uwa.edu.au
PURPOSE: Previous studies have shown that induced metabolic alkalosis, via sodium bicarbonate (NaHCO3) ingestion, can improve short-term, repeated-sprint ability. The purpose of this study was to assess the effects of NaHCO3 ingestion on a prolonged, intermittent-sprint test (IST). METHODS: Seven female team-sport athletes (mean +/- SD: age = 19 +/- 1 yr, VO2peak = 45.3 +/- 3.1 mL x kg(-1) x min(-1)) volunteered for the study, which had received ethics clearance. The athletes ingested two doses of either 0.2 g x kg(-1) of NaHCO3 or 0.138 g x kg(-1) of NaCl (placebo), in a double-blind, random, counterbalanced order, 90 and 20 min before performing the IST on a cycle ergometer (two 36-min "halves" of repeated approximately 2-min blocks: all-out 4-s sprint, 100 s of active recovery at 35% VO2peak, and 20 s of rest). Capillary blood samples were drawn from the ear lobe before ingestion, and before, during, and after each half of the IST. VO2 was also recorded at regular intervals throughout the IST. RESULTS: Resting plasma bicarbonate concentration ([HCO3-]) averaged 22.6 +/- 0.9 mmol x L(-1), and at 90 min post-ingestion was 21.4 +/- 1.5 and 28.9 +/- 2.8 mmol x L-1 for the placebo and NaHCO3 conditions, respectively (P < 0.05). Plasma [HCO3-] during the NaHCO3 condition remained significantly higher throughout the IST compared with both placebo and pre-ingestion. There was a trend toward improved total work in the second (P = 0.08), but not first, half of the IST after the ingestion of NaHCO3. Furthermore, subjects completed significantly more work in 7 of 18 second-half, 4-s sprints after NaHCO3 ingestion. CONCLUSIONS: The results of this study suggest that NaHCO3 ingestion can improve intermittent-sprint performance and may be a useful supplement for team-sport athletes.
Publication Types:
* Clinical Trial
* Randomized Controlled Trial
PMID: 15870629 [PubMed - indexed for MEDLINE]
9: J Strength Cond Res. 2005 Feb;19(1):213-24.
Related Articles, Links
Sodium bicarbonate and sodium citrate: ergogenic aids?
Requena B, Zabala M, Padial P, Feriche B.
Department of Physical Education and Sport, University of Granada, Spain. brequena@ugr.es
Numerous studies have used exogenous administration of sodium bicarbonate (NaHCO(3)) and sodium citrate (Na-citrate) in an attempt to enhance human performance. After ingestion of NaHCO(3) and Na-citrate, two observations have been made: (a) There was great individual variability in the ergogenic benefit reached, which can be attributed to the level of physical conditioning of the subjects and to their tolerance of the buffer substance; and (b) the subjects who had ingested NaHCO(3) and Na-citrate show higher levels of pH, bicarbonate, and lactate ions concentrations in their exercising blood than do the subjects who had ingested the placebo. A majority of the studies have suggested that the ingestion of both substances provides an ergogenic effect due to the establishment and maintenance of an elevated pH level during exercise. However, the exact mechanism by which the ergogenic effects occur has not been demonstrated conclusively. Sodium bicarbonate and Na-citrate seem to be effective in activities with a sufficient duration to generate a difference in the hydrogen ion gradient, characterized by a very high intensity and involving large muscular groups. However, in activities of equally high intensity, but with longer duration, the results obtained have been conflicting and inconclusive.
Publication Types:
* Review
PMID: 15705037 [PubMed - indexed for MEDLINE]
10: J Sports Sci. 2003 Jan;21(1):39-47.
Related Articles, Links
Sodium bicarbonate ingestion does not alter the slow component of oxygen uptake kinetics in professional cyclists.
Santalla A, Pérez M, Montilla M, Vicente L, Davison R, Earnest C, LucÃa A.
Universidad Alfonso X El Sabio, Villanueva de la Cañada, Madrid, Spain.
We examined the effects of pre-exercise sodium bicarbonate (NaHCO3) ingestion on the slow component of oxygen uptake (VO2) kinetics in seven professional road cyclists during intense exercise. One hour after ingesting either a placebo or NaHCO3 (0.3 g x kg body mass(-1)), each cyclist (age, 25 +/- 2 years; VO2max, 74.7 +/- 5.9 ml x kg(-1) x min(-1); mean +/- s) performed two bouts of 6 min duration at an intensity of 90% VO2max interspersed by 8 min of active recovery. Gas exchange and blood data (pH, blood lactate concentration and [HCO3-]) were collected during the tests. In both bouts, the slow component of VO2 was defined as the difference between end-exercise VO2 and the VO2 at the end of the third minute. No significant difference was found in the slow component of VO2 between conditions in the first (NaHCO3, 210 +/- 69 ml; placebo, 239 +/- 105 ml) or second trial (NaHCO3, 123 +/- 88 ml; placebo, 197 +/- 101 ml). In conclusion, pre-exercise NaHCO3 ingestion did not significantly attenuate the VO2 slow component of professional road cyclists during high-intensity exercise.
Publication Types:
* Clinical Trial
* Randomized Controlled Trial
PMID: 12587890 [PubMed - indexed for MEDLINE]
11: J Appl Physiol. 2002 Aug;93(2):724-31.
Related Articles, Links
Click here to read
Bicarbonate attenuates arterial desaturation during maximal exercise in humans.
Nielsen HB, Bredmose PP, Strømstad M, Volianitis S, Quistorff B, Secher NH.
The Copenhagen Muscle Research Center, Department of Anesthesia, Rigshospitalet, DK-2100 Copenhagen, Denmark. h.bay@dadlnet.dk
The contribution of pH to exercise-induced arterial O2 desaturation was evaluated by intravenous infusion of sodium bicarbonate (Bic, 1 M; 200-350 ml) or an equal volume of saline (Sal; 1 M) at a constant infusion rate during a "2,000-m" maximal ergometer row in five male oarsmen. Blood-gas variables were corrected to the increase in blood temperature from 36.5 +/- 0.3 to 38.9 +/- 0.1 degrees C (P < 0.05; means +/- SE), which was established in a pilot study. During Sal exercise, pH decreased from 7.42 +/- 0.01 at rest to 7.07 +/- 0.02 but only to 7.34 +/- 0.02 (P < 0.05) during the Bic trial. Arterial PO2 was reduced from 103.1 +/- 0.7 to 88.2 +/- 1.3 Torr during exercise with Sal, and this reduction was not significantly affected by Bic. Arterial O2 saturation was 97.5 +/- 0.2% at rest and decreased to 89.0 +/- 0.7% during Sal exercise but only to 94.1 +/- 1% with Bic (P < 0.05). Arterial PCO2 was not significantly changed from resting values in the last minute of Sal exercise, but in the Bic trial it increased from 40.5 +/- 0.5 to 45.9 +/- 2.0 Torr (P < 0.05). Pulmonary ventilation was lowered during exercise with Bic (155 +/- 14 vs. 142 +/- 13 l/min; P < 0.05), but the exercise-induced increase in the difference between the end-tidal O2 pressure and arterial PO2 was similar in the two trials. Also, pulmonary O2 uptake and changes in muscle oxygenation as determined by near-infrared spectrophotometry during exercise were similar. The enlarged blood-buffering capacity after infusion of Bic attenuated acidosis and in turn arterial desaturation during maximal exercise.
Publication Types:
* Clinical Trial
* Research Support, Non-U.S. Gov't
PMID: 12133884 [PubMed - indexed for MEDLINE]
12: Eur J Appl Physiol. 2002 May;87(1):72-7. Epub 2002 Mar 27.
Related Articles, Links
Click here to read
Effect of alkalosis on plasma epinephrine responses to high intensity cycle exercise in humans.
Marx JO, Gordon SE, Vos NH, Nindl BC, Gómez AL, Volek JS, Pedro J, Ratamess N, Newton RU, French DN, Rubin MR, Häkkinen K, Kraemer WJ.
Laboratory for Sports Medicine, The Pennsylvania State University, University Park, PA 16802, USA.
The purpose of this study was to determine the effects of alkalosis on epinephrine concentrations in response to a 90 s maximal exercise test. A group of ten healthy men ingested either a bicarbonate (BS) supplement (0.3 g x kg(-1) of body mass of sodium bicarbonate) or placebo mixture (P) prior to performing a 90 s maximal cycle ergometer test. An indwelling Teflon cannula was placed in the antecubital vein and blood samples were drawn at three times at rest separated by 10 min, immediately following the protocol, and at 2.5, 5, and 10 min post exercise to determine plasma epinephrine concentrations. Sodium bicarbonate ingestion significantly ( P<0.05) induced alkalosis both at rest [mean (SD) pH=7.42 (0.02) BS, 7.38 (0.02) P] and after the exercise protocol [pH=7.16 (0.02) BS, 7.12 (0.02) P]. Plasma epinephrine concentrations were not significantly different immediately post exercise between the two conditions [4.2 (0.6) compared to 4.2 (0.7) pmol x ml(-1) in BS and P, respectively]. Work performed and power output attained were not significantly different between the two treatment conditions [mean power=258.7 (35.1) W BS, 260.3 (35.4) W P; peak power=534.7 (61.6) W BS, 535.7 (54.4) W P]. The primary finding of this investigation was that orally-induced alkalosis does not significantly affect plasma epinephrine concentrations or performance following 90 s of maximal cycle exercise in untrained men.
Publication Types:
* Clinical Trial
* Controlled Clinical Trial
PMID: 12012079 [PubMed - indexed for MEDLINE]
13: Med Sci Sports Exerc. 2002 Apr;34(4):614-21.
Related Articles, Links
Click here to read
Effect of sodium bicarbonate on muscle metabolism during intense endurance cycling.
Stephens TJ, McKenna MJ, Canny BJ, Snow RJ, McConell GK.
Department of Physiology, Monash University, Clayton, 3800 Victoria, Australia.
INTRODUCTION: Sodium bicarbonate (NaHCO3) ingestion has been shown to increase both muscle glycogenolysis and glycolysis during brief submaximal exercise. These changes may be detrimental to performance during more prolonged, exhaustive exercise. This study examined the effect of NaHCO3 ingestion on muscle metabolism and performance during intense endurance exercise of approximately 60 min in seven endurance-trained men. METHODS: Subjects ingested 0.3 g.kg-1 body mass of either NaHCO3 or CaCO3 (CON) 2 h before performing 30 min of cycling exercise at 77 +/- 1% .VO(2peak) followed by completion of 469 +/- 21 kJ as quickly as possible (approximately 30 min, approximately 80% .VO(2peak)). RESULTS: Immediately before, and throughout exercise, arterialized-venous plasma HCO3- concentrations were higher (P < 0.05) whereas plasma and muscle H+ concentrations were lower (P < 0.05) in NaHCO3 compared with CON. Blood lactate concentrations were higher (P < 0.05) during exercise in NaHCO3, but there was no difference between trials in muscle glycogen utilization or muscle lactate content during exercise. Reductions in PCr and ATP and increases in muscle Cr during exercise were also unaffected by NaHCO3 ingestion. Accordingly, exercise performance time was not different between treatments. CONCLUSION: NaHCO3 ingestion resulted in a small muscle alkalosis but had no effect on muscle metabolism or intense endurance exercise performance in well-trained men.
PMID: 11932569 [PubMed - indexed for MEDLINE]
14: J Sports Med Phys Fitness. 2001 Dec;41(4):456-62.
Related Articles, Links
Acute versus chronic sodium bicarbonate ingestion and anaerobic work and power output.
Mc Naughton L, Thompson D.
Department of Sport and Exercise Science, University of Bath, Bath, England, UK. l.mcnaughton@bath.ac.uk
BACKGROUND: The aim of this study was to compare and contrast the effects of acute versus chronic sodium bicarbonate ingestion. METHODS: PARTICIPANTS: Eight male, (mean+/-SE): age, 20.8+/-0.4 yrs; height, 179.6+/-0.6 cm; body mass, 79.4+/-0.85 kg, Sigma7skf, 48.6+/-4.8 mm, VO2max=55.9+/-0.8 ml x kg(-1) x min(-1)) volunteer subjects, ingested NaHCO3 in either a dose of 0.5 g x kg(-1) body mass acutely or the same dose daily over a period of six days in order to determine whether there were any differences in performance of 90 sec maximal cycling ergometry. INTERVENTION: After subjects undertook an initial control (C) test session, all were then randomly assigned to one of two groups, acute or chronic NaHCO3 ingestion. Subjects in the acute ingestion (AI) group completed their supplemented test on day one, and then on the following day. Chronic ingestion (CI) subjects completed the test after one day of chronic ingestion as well as following six days of bicarbonate ingestion. Following ten days rest, subjects repeated the protocol in the opposite group. MEASURES: Blood samples were taken pre- and postingestion, daily, and pre- and postexercise and were analysed for, pH, Base excess (BE), HCO3-, PO2, PCO2, Na+, K+, Cl-, and lactate. RESULTS: Both the chronic (CI) and acute ingestion (AI) groups were significantly different to the control (C) value (p<0.001 and p<0.05, respectively). CONCLUSIONS: We would suggest using chronic ingestion as a means to improve high intensity work rather than the acute ingestion of sodium bicarbonate. The ingestion of sodium bicarbonate, over a period of six days, significantly improved work output two days after bicarbonate ingestion ceased.
Publication Types:
* Clinical Trial
* Randomized Controlled Trial
* Research Support, Non-U.S. Gov't
PMID: 11687764 [PubMed - indexed for MEDLINE]
15: Eur J Appl Physiol Occup Physiol. 1996;72(4):365-71.
Related Articles, Links
The effects of buffer ingestion on metabolic factors related to distance running performance.
Potteiger JA, Webster MJ, Nickel GL, Haub MD, Palmer RJ.
Exercise Physiology Laboratory, University of Kansas 66045, USA.
We examined the effects of sodium bicarbonate (BIC) and sodium citrate (CIT) ingestion on distance running performance. Seven male runners [mean VO2max = 61.7 (SEM 1.7) ml.kg-1.min-1] performed three 30-min treadmill runs at the lactate threshold (LT) each followed by a run to exhaustion at 110% of LT. The runs were double-blind and randomly assigned from BIC (0.3 g.kg body mass-1), CIT (0.5 g.kg body mass-1) and placebo (PLC, wheat flour, 0.5 g.kg body mass-1). Venous blood samples were collected at 5, 15 and 25 min during the run and immediately post-exhaustion (POST-EX) and analysed for pH, and the concentrations of lactate ([la-]b) and bicarbonate ([HCO3-]). Performance was measured as running time to exhaustion at 110% of LT (TIME-EX). The pH was significantly higher (P < or = 0.05) for the BIC and CIT trials during exercise, but not POST-EX compared to PLC. The [la-]b was significantly higher (P < or = 0.05) for the CIT trial compared to PLC during exercise, and for both CIT and BIC compared to PLC at POST-EX. Blood [HCO3-] was significantly higher (P < or = 0.05) during exercise for BIC compared to PLC. TIME-EX was not significantly different among treatments: BIC 287 (SEM 47.4)s; CIT 172.8 (SEM 29.7)s; and PLC 222.3 (SEM 39.7)s. Despite the fact that buffer ingestion produced favourable metabolic conditions during 30 min of high intensity steady-state exercise, a significant improvement in the subsequent maximal exercise run to exhaustion did not occur.
Publication Types:
* Clinical Trial
* Randomized Controlled Trial
* Research Support, Non-U.S. Gov't
PMID: 8851907 [PubMed - indexed for MEDLINE]
16: Eur J Appl Physiol Occup Physiol. 1999 Sep;80(4):333-6.
Related Articles, Links
Effects of chronic bicarbonate ingestion on the performance of high-intensity work.
McNaughton L, Backx K, Palmer G, Strange N.
Sports Science, Kingston University, Kingston upon Thames, Surrey, UK.
We have evaluated whether sodium bicarbonate, taken chronically (0.5 g x kg(-1) body mass) for a period of 5 days would improve the performance of eight subjects during 60 s of high-intensity exercise on an electrically braked cycle ergometer. The first test was performed prior to chronic supplementation (pre-ingestion) while the post-ingestion test took place 6 days later. A control test took place approximately 1 month after the cessation of all testing. Acid-base and metabolite data (n = 7) were measured from arterialised blood both pre- and post-exercise, as well as daily throughout the exercise period. The work completed by the subjects in the control and pre-ingestion test [21.1 (0.9) and 21.1 (0.9) MJ, respectively] was less than (P<0.05) that completed in the post-ingestion test [24.1 (0.9) MJ; F(2,21) = 3.4, P<0.05, power = 0.57]. Peak power was higher after the 5-day supplementation period (P<0.05). Ingestion of the sodium bicarbonate for a period of 5 days resulted in an increase in pH (F(5,36) = 12.5, P<0.0001, power = 1.0) over the 5-day period. The blood bicarbonate levels also rose during the trial (P<0.05) from a resting level of 22.8 (0.4) to 28.4 (1.1) mmol x l(-1) after 24 h of ingestion. In conclusion, the addition of sodium bicarbonate to a normal diet proved to be of ergogenic benefit in the performance of short-term, high-intensity work.
Publication Types:
* Clinical Trial
* Research Support, Non-U.S. Gov't
PMID: 10483803 [PubMed - indexed for MEDLINE]
Items 1 - 16 of 16
One page.
Display Show
* About Entrez
* Text Version
*
Entrez PubMed
* Overview
* Help | FAQ
* Tutorials
* New/NoteworthyNew/Noteworthy Web (RSS) Feed
* E-Utilities
*
PubMed Services
* Journals Database
* MeSH Database
* Single Citation Matcher
* Batch Citation Matcher
* Clinical Queries
* Special Queries
* LinkOut
* My NCBI
*
Related Resources
* Order Documents
* NLM Mobile
* NLM Catalog
* NLM Gateway
* TOXNET
* Consumer Health
* Clinical Alerts
* ClinicalTrials.gov
* PubMed Central
* Write to the Help Desk
* NCBI | NLM | NIH
* Department of Health & Human Services
* Privacy Statement | Freedom of Information Act | Disclaimer
Items 1 - 16 of 16
One page.
1: Int J Sports Med. 2008 Jul;29(7):545-51. Epub 2007 Nov 14.
Related Articles, Links
Click here to read
Pre-exercise alkalosis and acid-base recovery.
Siegler JC, Keatley S, Midgley AW, Nevill AM, McNaughton LR.
Department of Sport, Health and Exercise Science, University of Hull, Hull, United Kingdom. J.Siegler@hull.ac.uk
The aim of this study was to observe the influence of pre-exercise sodium bicarbonate (NaHCO3) ingestion and varying recovery modes on acid-base recovery from a single bout of supramaximal exercise. Nine male subjects completed four separate, randomized cycle ergometer exercise trials to volitional fatigue at 120% maximum power output, under the following conditions: 0.3 g.kg(-1) BW NaHCO3 ingestion with passive recovery (BICARB P), 0.3 g.kg (-1) BW NaHCO3 ingestion with active recovery (BICARB A), placebo ingestion with passive recovery (PLAC P) and placebo ingestion with active recovery (PLAC A). Capillary blood samples were obtained every minute for 15 min during recovery. Significant main effects for pH were observed for time (F = 42.1, p < 0.001), intervention (BICARB and PLAC) (F = 1117.3, p < 0.001) and recovery condition (F = 150.0, p < 0.001), as the BICARB condition reduced acid-base perturbation. Significant interaction effects were observed between conditions (BICARB and PLAC) for active and passive recovery modes (F = 29.1, p < 0.001) as the active recovery facilitated H+ removal better than the passive condition. Pre-exercise alkalosis attenuates blood acid-base perturbations from supramaximal exercise to exhaustion, regardless of whether the recovery mode is active or passive. These findings suggest that individuals may benefit from introducing a pre-exercise alkalotic condition while including passive recovery during high-intensity training protocols.
Publication Types:
* Randomized Controlled Trial
PMID: 18004683 [PubMed - indexed for MEDLINE]
2: Eur J Appl Physiol. 2007 Nov;101(4):409-17. Epub 2007 Jul 13.
Related Articles, Links
Click here to read
Effect of oral administration of sodium bicarbonate on surface EMG activity during repeated cycling sprints.
Matsuura R, Arimitsu T, Kimura T, Yunoki T, Yano T.
Laboratory of Exercise Physiology, Graduate School of Education, Hokkaido University, Kita-11, Nishi-7, Kita-ku, Sapporo, 060-0811, Japan. dj-ryota@edu.hokudai.ac.jp
The purpose of this study was to determine the effect of oral administration of sodium bicarbonate (NaHCO3) on surface electromyogram (SEMG) activity from the vastus lateralis (VL) during repeated cycling sprints (RCS). Subjects performed two RCS tests (ten 10-s sprints) interspersed with both 30-s and 360-s recovery periods 1 h after oral administration of either NaHCO3 (RCSAlk) or CaCO3 (RCSPla) in a random counterbalanced order. Recovery periods of 360 s were set before the 5th and 9th sprints. The rate of decrease in plasma HCO3- concentration during RCS was significantly greater in RCSAlk than in RCSPla, but the rates of decline in blood pH during the two RCS tests were similar. There was no difference between change in plasma lactate concentration in RCSAlk and that in RCSPla. Performance during RCSAlk was similar to that during RCSPla. There were no differences in oxygen uptake immediately before each cycling sprint (preVO2) and in SEMG activity between RCSAlk and RCSPla. In conclusion, oral administration of NaHCO3 did not affect SEMG activity from the VL. This suggests that the muscle recruitment strategy during RCS is not determined by only intramuscular pH.
Publication Types:
* Randomized Controlled Trial
PMID: 17628824 [PubMed - indexed for MEDLINE]
3: Med Sci Sports Exerc. 2006 Nov;38(11):1909-17.
Related Articles, Links
Click here to read
Sodium bicarbonate ingestion alters the slow but not the fast phase of VO2 kinetics.
Berger NJ, McNaughton LR, Keatley S, Wilkerson DP, Jones AM.
Department of Exercise and Sport Science, Manchester Metropolitan University, Hassall Road, Alsager, UK.
PURPOSE: The influence of metabolic alkalosis (ALK) on pulmonary O2 uptake (pVO2) kinetics during high-intensity cycle exercise is controversial. The purpose of this study was to examine the influence of ALK induced by sodium bicarbonate (NaHCO3) ingestion on pVO2 kinetics, using a sufficient number of repeat-step transitions to provide high confidence in the results obtained. METHODS: Seven healthy males completed step tests to a work rate requiring 80% pVO2max on six separate occasions: three times after ingestion of 0.3 g x kg(-1) body mass NaHCO3 in 1 L of fluid, and three times after ingestion of a placebo (CON). Blood samples were taken to assess changes in acid-base balance, and pVO2 was measured breath-by-breath. RESULTS: NaHCO3 ingestion significantly increased blood pH and [bicarbonate] both before and during exercise relative to the control condition (P < 0.001). The time constant of the phase II pVO2 response was not different between conditions (CON: 29 +/- 6 vs ALK: 32 +/- 7 s; P = 0.21). However, the onset of the pVO2 slow component was delayed by NaHCO3 ingestion (CON: 120 +/- 19 vs ALK: 147 +/- 34 s; P < 0.01), resulting in a significantly reduced end-exercise pVO2 (CON: 2.88 +/- 0.19 vs ALK: 2.79 +/- 0.23 L x min(-1); P < 0.05). CONCLUSIONS: Metabolic alkalosis has no effect on phase II pVO2 kinetics but alters the pVO2 slow-component response, possibly as a result of the effects of NaHCO3 ingestion on muscle pH.
Publication Types:
* Randomized Controlled Trial
PMID: 17095923 [PubMed - indexed for MEDLINE]
4: Eur J Appl Physiol. 2007 Jan;99(2):173-81. Epub 2006 Nov 7.
Related Articles, Links
Click here to read
Potassium kinetics and its relationship with ventilation during repeated bouts of exercise in women.
Zavorsky GS, Gow J, Murias JM.
Department of Anesthesia, McGill University Health Center, Montreal General Hospital, 1650 Cedar Avenue, Room D10-144, H3G 1A4, Montreal, QC, Canada. gerald.zavorsky@mcgill.ca
The purpose of this study was to determine the electrolyte concentration changes in arterial plasma from high-intensity repeated bouts of cycling exercise in well-trained females and to determine the relationships between arterial plasma lactate, potassium (K+), bicarbonate (HCO3(-)), and pH with minute ventilation. Fourteen female subjects (mean age = 27 +/- 4 years; mean height = 170 +/- 7 cm; mean weight = 62 +/- 7 kg; maximal oxygen uptake = 50 +/- 6 ml/kg/min) were recruited to perform 3 x 5 min bouts of exercise at 236 +/- 27 W with 10 min recovery between each set. Minute ventilation, arterial plasma lactate, potassium, calcium, chloride, and sodium ion concentrations were measured a minute 0, 1, 2, 3, 4, 5 of each set and midway through recovery (21 sampling points total per subject). The results showed that the strongest relationship was between arterial plasma K+ concentration and minute ventilation (r2 = 0.91), and, that arterial plasma lactate mirrored both arterial plasma HCO3(-) and pH. In conclusion, this study demonstrates that women exhibit similar electrolyte responses as reported elsewhere in men, and support the idea that K+ may partly contribute to controlling ventilation during high-intensity exercise and recovery.
PMID: 17089156 [PubMed - indexed for MEDLINE]
5: Med Sci Sports Exerc. 2006 Oct;38(10):1746-53.
Related Articles, Links
Click here to read
Dose-related effects of prolonged NaHCO3 ingestion during high-intensity exercise.
Douroudos II, Fatouros IG, Gourgoulis V, Jamurtas AZ, Tsitsios T, Hatzinikolaou A, Margonis K, Mavromatidis K, Taxildaris K.
Democritus University of Thrace, Department of Physical Education & Sport Science, Komotini, Greece.
PURPOSE: Sodium bicarbonate (NaHCO3) ingestion may prevent exercise-induced perturbations in acid-base balance, thus resulting in performance enhancement. This study aimed to determine whether different levels of NaHCO3 intake influences acid-base balance and performance during high-intensity exercise after 5 d of supplementation. METHODS: Twenty-four men (22 +/- 1.7 yr) were randomly assigned to one of three groups (eight subjects per group): control (C, placebo), moderate NaHCO3 intake (MI, 0.3 g x kg(-1) x d(-1)), and high NaHCO3 intake (HI, 0.5 g x kg(-1) x d(-1)). Arterial pH, HCO3(-), PO2, PCO2, K+, Na, base excess (BE), lactate, and mean power (MP) were measured before and after a Wingate test pre- and postsupplementation. RESULTS: HCO3(-) increased proportionately to the dosage level. No differences were detected in C. Supplementation increased MP (W x kg(-)) in MI (7.36 +/- 0.7 vs 6.73 +/- 1.0) and HI (7.72 +/- 0.9 vs 6.69 +/- 0.6), with HI being more effective than MI. NaHCO3 ingestion resulted postexercise in increased lactate (mmol x L(-1)) (12.3 +/- 1.8 vs 10.3 +/- 1.9 and 12.4 +/- 1.2 vs 10.4 +/- 1.5 in MI and HI, respectively), reduced exercise-induced drop of pH (7.305 +/- 0.04 vs 7.198 +/- 0.02 and 7.343 +/- 0.05 vs 7.2 +/- 0.01 in MI and HI, respectively) and HCO3(-) (mmol x L(-1)) (13.1 +/- 2.4 vs 17.5 +/- 2.8 and 13.2 +/- 2.7 vs 19.8 +/- 3.2 for HCO3 in MI and HI, respectively), and reduced K (3.875 +/- 0.2 vs 3.625 +/- 0.3 mmol x L(-1) in MI and HI, respectively). CONCLUSION: NaHCO3 administration for 5 d may prevent acid-base balance disturbances and improve performance during anaerobic exercise in a dose-dependent manner.
Publication Types:
* Clinical Trial
* Randomized Controlled Trial
PMID: 17019296 [PubMed - indexed for MEDLINE]
6: QJM. 2006 Jul;99(7):475-85.
Related Articles, Links
Click here to read
Comment in:
* QJM. 2006 Dec;99(12):881; author reply 881-2.
The patient with a severe degree of metabolic acidosis: a deductive analysis.
Maccari C, Kamel KS, Davids MR, Halperin ML.
Division of Nephrology, St. Michael's Hospital, University of Toronto, Toronto, Ontario, M5B 1A6, Canada.
This teaching exercise demonstrates how principles of physiology might help in identifying the cause of a particularly severe case of metabolic acidosis and making appropriate decisions about therapy. The patient's plasma pH was 7.00 and their plasma bicarbonate concentration was 2 mmol/l. Because the time course of the patient's illness was believed to be <24 h, this suggested that a large quantity of acid had been added to the body in this short time period, but the medical team managing the case could not identify any acid that could have been produced rapidly by endogenous processes, or was ingested by the patient. Moreover, there was a question about how such a very low arterial PCO(2) (8 mmHg) could be sustained. Even once the diagnosis was made, there were issues to resolve concerning therapy. These included questions about how much sodium bicarbonate to administer, and what dangers might arise during this therapy. The missing links in this interesting story emerge during a discussion between the medical team and their imaginary mentor, Professor McCance.
Publication Types:
* Case Reports
PMID: 16835252 [PubMed - indexed for MEDLINE]
7: J Appl Physiol. 2005 Nov;99(5):1668-75. Epub 2005 Jul 7.
Related Articles, Links
Click here to read
NaHCO3-induced alkalosis reduces the phosphocreatine slow component during heavy-intensity forearm exercise.
Forbes SC, Raymer GH, Kowalchuk JM, Marsh GD.
School of Kinesiology, The University of Western Ontario, London, Ontario, Canada N6A-3K7.
During heavy-intensity exercise, the mechanisms responsible for the continued slow decline in phosphocreatine concentration ([PCr]) (PCr slow component) have not been established. In this study, we tested the hypothesis that a reduced intracellular acidosis would result in a greater oxidative flux and, consequently, a reduced magnitude of the PCr slow component. Subjects (n = 10) performed isotonic wrist flexion in a control trial and in an induced alkalosis (Alk) trial (0.3g/kg oral dose of NaHCO3, 90 min before testing). Wrist flexion, at a contraction rate of 0.5 Hz, was performed for 9 min at moderate- (75% of onset of acidosis; intracellular pH threshold) and heavy-intensity (125% intracellular pH threshold) exercise. 31P-magnetic resonance spectroscopy was used to measure intracellular [H+], [PCr], [Pi], and [ATP]. The initial recovery data were used to estimate the rate of ATP synthesis and oxidative flux at the end of heavy-intensity exercise. In repeated trials, venous blood sampling was used to measure plasma [H+], [HCO3-], and [Lac-]. Throughout rest and exercise, plasma [H+] was lower (P < 0.05) and [HCO3-] was elevated (P < 0.05) in Alk compared with control. During the final 3 min of heavy-intensity exercise, Alk caused a lower (P < 0.05) intracellular [H+] [246 (SD 117) vs. 291 nmol/l (SD 129)], a greater (P <0> 0.05) in the conditions at the end of heavy-intensity exercise. In conclusion, our results are consistent with a reduced intracellular acidosis, causing a decrease in the magnitude of the PCr slow component. The decreased PCr slow component in Alk did not appear to be due to an elevated oxidative flux.
Publication Types:
* Clinical Trial
PMID: 16002768 [PubMed - indexed for MEDLINE]
8: Med Sci Sports Exerc. 2005 May;37(5):759-67.
Related Articles, Links
Click here to read
Effects of induced metabolic alkalosis on prolonged intermittent-sprint performance.
Bishop D, Claudius B.
Team Sport Research Group, School of Human Movement and Exercise Science, The University of Western Australia, Crawley, WA, Australia. dbishop@cyllene.uwa.edu.au
PURPOSE: Previous studies have shown that induced metabolic alkalosis, via sodium bicarbonate (NaHCO3) ingestion, can improve short-term, repeated-sprint ability. The purpose of this study was to assess the effects of NaHCO3 ingestion on a prolonged, intermittent-sprint test (IST). METHODS: Seven female team-sport athletes (mean +/- SD: age = 19 +/- 1 yr, VO2peak = 45.3 +/- 3.1 mL x kg(-1) x min(-1)) volunteered for the study, which had received ethics clearance. The athletes ingested two doses of either 0.2 g x kg(-1) of NaHCO3 or 0.138 g x kg(-1) of NaCl (placebo), in a double-blind, random, counterbalanced order, 90 and 20 min before performing the IST on a cycle ergometer (two 36-min "halves" of repeated approximately 2-min blocks: all-out 4-s sprint, 100 s of active recovery at 35% VO2peak, and 20 s of rest). Capillary blood samples were drawn from the ear lobe before ingestion, and before, during, and after each half of the IST. VO2 was also recorded at regular intervals throughout the IST. RESULTS: Resting plasma bicarbonate concentration ([HCO3-]) averaged 22.6 +/- 0.9 mmol x L(-1), and at 90 min post-ingestion was 21.4 +/- 1.5 and 28.9 +/- 2.8 mmol x L-1 for the placebo and NaHCO3 conditions, respectively (P < 0.05). Plasma [HCO3-] during the NaHCO3 condition remained significantly higher throughout the IST compared with both placebo and pre-ingestion. There was a trend toward improved total work in the second (P = 0.08), but not first, half of the IST after the ingestion of NaHCO3. Furthermore, subjects completed significantly more work in 7 of 18 second-half, 4-s sprints after NaHCO3 ingestion. CONCLUSIONS: The results of this study suggest that NaHCO3 ingestion can improve intermittent-sprint performance and may be a useful supplement for team-sport athletes.
Publication Types:
* Clinical Trial
* Randomized Controlled Trial
PMID: 15870629 [PubMed - indexed for MEDLINE]
9: J Strength Cond Res. 2005 Feb;19(1):213-24.
Related Articles, Links
Sodium bicarbonate and sodium citrate: ergogenic aids?
Requena B, Zabala M, Padial P, Feriche B.
Department of Physical Education and Sport, University of Granada, Spain. brequena@ugr.es
Numerous studies have used exogenous administration of sodium bicarbonate (NaHCO(3)) and sodium citrate (Na-citrate) in an attempt to enhance human performance. After ingestion of NaHCO(3) and Na-citrate, two observations have been made: (a) There was great individual variability in the ergogenic benefit reached, which can be attributed to the level of physical conditioning of the subjects and to their tolerance of the buffer substance; and (b) the subjects who had ingested NaHCO(3) and Na-citrate show higher levels of pH, bicarbonate, and lactate ions concentrations in their exercising blood than do the subjects who had ingested the placebo. A majority of the studies have suggested that the ingestion of both substances provides an ergogenic effect due to the establishment and maintenance of an elevated pH level during exercise. However, the exact mechanism by which the ergogenic effects occur has not been demonstrated conclusively. Sodium bicarbonate and Na-citrate seem to be effective in activities with a sufficient duration to generate a difference in the hydrogen ion gradient, characterized by a very high intensity and involving large muscular groups. However, in activities of equally high intensity, but with longer duration, the results obtained have been conflicting and inconclusive.
Publication Types:
* Review
PMID: 15705037 [PubMed - indexed for MEDLINE]
10: J Sports Sci. 2003 Jan;21(1):39-47.
Related Articles, Links
Sodium bicarbonate ingestion does not alter the slow component of oxygen uptake kinetics in professional cyclists.
Santalla A, Pérez M, Montilla M, Vicente L, Davison R, Earnest C, LucÃa A.
Universidad Alfonso X El Sabio, Villanueva de la Cañada, Madrid, Spain.
We examined the effects of pre-exercise sodium bicarbonate (NaHCO3) ingestion on the slow component of oxygen uptake (VO2) kinetics in seven professional road cyclists during intense exercise. One hour after ingesting either a placebo or NaHCO3 (0.3 g x kg body mass(-1)), each cyclist (age, 25 +/- 2 years; VO2max, 74.7 +/- 5.9 ml x kg(-1) x min(-1); mean +/- s) performed two bouts of 6 min duration at an intensity of 90% VO2max interspersed by 8 min of active recovery. Gas exchange and blood data (pH, blood lactate concentration and [HCO3-]) were collected during the tests. In both bouts, the slow component of VO2 was defined as the difference between end-exercise VO2 and the VO2 at the end of the third minute. No significant difference was found in the slow component of VO2 between conditions in the first (NaHCO3, 210 +/- 69 ml; placebo, 239 +/- 105 ml) or second trial (NaHCO3, 123 +/- 88 ml; placebo, 197 +/- 101 ml). In conclusion, pre-exercise NaHCO3 ingestion did not significantly attenuate the VO2 slow component of professional road cyclists during high-intensity exercise.
Publication Types:
* Clinical Trial
* Randomized Controlled Trial
PMID: 12587890 [PubMed - indexed for MEDLINE]
11: J Appl Physiol. 2002 Aug;93(2):724-31.
Related Articles, Links
Click here to read
Bicarbonate attenuates arterial desaturation during maximal exercise in humans.
Nielsen HB, Bredmose PP, Strømstad M, Volianitis S, Quistorff B, Secher NH.
The Copenhagen Muscle Research Center, Department of Anesthesia, Rigshospitalet, DK-2100 Copenhagen, Denmark. h.bay@dadlnet.dk
The contribution of pH to exercise-induced arterial O2 desaturation was evaluated by intravenous infusion of sodium bicarbonate (Bic, 1 M; 200-350 ml) or an equal volume of saline (Sal; 1 M) at a constant infusion rate during a "2,000-m" maximal ergometer row in five male oarsmen. Blood-gas variables were corrected to the increase in blood temperature from 36.5 +/- 0.3 to 38.9 +/- 0.1 degrees C (P < 0.05; means +/- SE), which was established in a pilot study. During Sal exercise, pH decreased from 7.42 +/- 0.01 at rest to 7.07 +/- 0.02 but only to 7.34 +/- 0.02 (P < 0.05) during the Bic trial. Arterial PO2 was reduced from 103.1 +/- 0.7 to 88.2 +/- 1.3 Torr during exercise with Sal, and this reduction was not significantly affected by Bic. Arterial O2 saturation was 97.5 +/- 0.2% at rest and decreased to 89.0 +/- 0.7% during Sal exercise but only to 94.1 +/- 1% with Bic (P < 0.05). Arterial PCO2 was not significantly changed from resting values in the last minute of Sal exercise, but in the Bic trial it increased from 40.5 +/- 0.5 to 45.9 +/- 2.0 Torr (P < 0.05). Pulmonary ventilation was lowered during exercise with Bic (155 +/- 14 vs. 142 +/- 13 l/min; P < 0.05), but the exercise-induced increase in the difference between the end-tidal O2 pressure and arterial PO2 was similar in the two trials. Also, pulmonary O2 uptake and changes in muscle oxygenation as determined by near-infrared spectrophotometry during exercise were similar. The enlarged blood-buffering capacity after infusion of Bic attenuated acidosis and in turn arterial desaturation during maximal exercise.
Publication Types:
* Clinical Trial
* Research Support, Non-U.S. Gov't
PMID: 12133884 [PubMed - indexed for MEDLINE]
12: Eur J Appl Physiol. 2002 May;87(1):72-7. Epub 2002 Mar 27.
Related Articles, Links
Click here to read
Effect of alkalosis on plasma epinephrine responses to high intensity cycle exercise in humans.
Marx JO, Gordon SE, Vos NH, Nindl BC, Gómez AL, Volek JS, Pedro J, Ratamess N, Newton RU, French DN, Rubin MR, Häkkinen K, Kraemer WJ.
Laboratory for Sports Medicine, The Pennsylvania State University, University Park, PA 16802, USA.
The purpose of this study was to determine the effects of alkalosis on epinephrine concentrations in response to a 90 s maximal exercise test. A group of ten healthy men ingested either a bicarbonate (BS) supplement (0.3 g x kg(-1) of body mass of sodium bicarbonate) or placebo mixture (P) prior to performing a 90 s maximal cycle ergometer test. An indwelling Teflon cannula was placed in the antecubital vein and blood samples were drawn at three times at rest separated by 10 min, immediately following the protocol, and at 2.5, 5, and 10 min post exercise to determine plasma epinephrine concentrations. Sodium bicarbonate ingestion significantly ( P<0.05) induced alkalosis both at rest [mean (SD) pH=7.42 (0.02) BS, 7.38 (0.02) P] and after the exercise protocol [pH=7.16 (0.02) BS, 7.12 (0.02) P]. Plasma epinephrine concentrations were not significantly different immediately post exercise between the two conditions [4.2 (0.6) compared to 4.2 (0.7) pmol x ml(-1) in BS and P, respectively]. Work performed and power output attained were not significantly different between the two treatment conditions [mean power=258.7 (35.1) W BS, 260.3 (35.4) W P; peak power=534.7 (61.6) W BS, 535.7 (54.4) W P]. The primary finding of this investigation was that orally-induced alkalosis does not significantly affect plasma epinephrine concentrations or performance following 90 s of maximal cycle exercise in untrained men.
Publication Types:
* Clinical Trial
* Controlled Clinical Trial
PMID: 12012079 [PubMed - indexed for MEDLINE]
13: Med Sci Sports Exerc. 2002 Apr;34(4):614-21.
Related Articles, Links
Click here to read
Effect of sodium bicarbonate on muscle metabolism during intense endurance cycling.
Stephens TJ, McKenna MJ, Canny BJ, Snow RJ, McConell GK.
Department of Physiology, Monash University, Clayton, 3800 Victoria, Australia.
INTRODUCTION: Sodium bicarbonate (NaHCO3) ingestion has been shown to increase both muscle glycogenolysis and glycolysis during brief submaximal exercise. These changes may be detrimental to performance during more prolonged, exhaustive exercise. This study examined the effect of NaHCO3 ingestion on muscle metabolism and performance during intense endurance exercise of approximately 60 min in seven endurance-trained men. METHODS: Subjects ingested 0.3 g.kg-1 body mass of either NaHCO3 or CaCO3 (CON) 2 h before performing 30 min of cycling exercise at 77 +/- 1% .VO(2peak) followed by completion of 469 +/- 21 kJ as quickly as possible (approximately 30 min, approximately 80% .VO(2peak)). RESULTS: Immediately before, and throughout exercise, arterialized-venous plasma HCO3- concentrations were higher (P < 0.05) whereas plasma and muscle H+ concentrations were lower (P < 0.05) in NaHCO3 compared with CON. Blood lactate concentrations were higher (P < 0.05) during exercise in NaHCO3, but there was no difference between trials in muscle glycogen utilization or muscle lactate content during exercise. Reductions in PCr and ATP and increases in muscle Cr during exercise were also unaffected by NaHCO3 ingestion. Accordingly, exercise performance time was not different between treatments. CONCLUSION: NaHCO3 ingestion resulted in a small muscle alkalosis but had no effect on muscle metabolism or intense endurance exercise performance in well-trained men.
PMID: 11932569 [PubMed - indexed for MEDLINE]
14: J Sports Med Phys Fitness. 2001 Dec;41(4):456-62.
Related Articles, Links
Acute versus chronic sodium bicarbonate ingestion and anaerobic work and power output.
Mc Naughton L, Thompson D.
Department of Sport and Exercise Science, University of Bath, Bath, England, UK. l.mcnaughton@bath.ac.uk
BACKGROUND: The aim of this study was to compare and contrast the effects of acute versus chronic sodium bicarbonate ingestion. METHODS: PARTICIPANTS: Eight male, (mean+/-SE): age, 20.8+/-0.4 yrs; height, 179.6+/-0.6 cm; body mass, 79.4+/-0.85 kg, Sigma7skf, 48.6+/-4.8 mm, VO2max=55.9+/-0.8 ml x kg(-1) x min(-1)) volunteer subjects, ingested NaHCO3 in either a dose of 0.5 g x kg(-1) body mass acutely or the same dose daily over a period of six days in order to determine whether there were any differences in performance of 90 sec maximal cycling ergometry. INTERVENTION: After subjects undertook an initial control (C) test session, all were then randomly assigned to one of two groups, acute or chronic NaHCO3 ingestion. Subjects in the acute ingestion (AI) group completed their supplemented test on day one, and then on the following day. Chronic ingestion (CI) subjects completed the test after one day of chronic ingestion as well as following six days of bicarbonate ingestion. Following ten days rest, subjects repeated the protocol in the opposite group. MEASURES: Blood samples were taken pre- and postingestion, daily, and pre- and postexercise and were analysed for, pH, Base excess (BE), HCO3-, PO2, PCO2, Na+, K+, Cl-, and lactate. RESULTS: Both the chronic (CI) and acute ingestion (AI) groups were significantly different to the control (C) value (p<0.001 and p<0.05, respectively). CONCLUSIONS: We would suggest using chronic ingestion as a means to improve high intensity work rather than the acute ingestion of sodium bicarbonate. The ingestion of sodium bicarbonate, over a period of six days, significantly improved work output two days after bicarbonate ingestion ceased.
Publication Types:
* Clinical Trial
* Randomized Controlled Trial
* Research Support, Non-U.S. Gov't
PMID: 11687764 [PubMed - indexed for MEDLINE]
15: Eur J Appl Physiol Occup Physiol. 1996;72(4):365-71.
Related Articles, Links
The effects of buffer ingestion on metabolic factors related to distance running performance.
Potteiger JA, Webster MJ, Nickel GL, Haub MD, Palmer RJ.
Exercise Physiology Laboratory, University of Kansas 66045, USA.
We examined the effects of sodium bicarbonate (BIC) and sodium citrate (CIT) ingestion on distance running performance. Seven male runners [mean VO2max = 61.7 (SEM 1.7) ml.kg-1.min-1] performed three 30-min treadmill runs at the lactate threshold (LT) each followed by a run to exhaustion at 110% of LT. The runs were double-blind and randomly assigned from BIC (0.3 g.kg body mass-1), CIT (0.5 g.kg body mass-1) and placebo (PLC, wheat flour, 0.5 g.kg body mass-1). Venous blood samples were collected at 5, 15 and 25 min during the run and immediately post-exhaustion (POST-EX) and analysed for pH, and the concentrations of lactate ([la-]b) and bicarbonate ([HCO3-]). Performance was measured as running time to exhaustion at 110% of LT (TIME-EX). The pH was significantly higher (P < or = 0.05) for the BIC and CIT trials during exercise, but not POST-EX compared to PLC. The [la-]b was significantly higher (P < or = 0.05) for the CIT trial compared to PLC during exercise, and for both CIT and BIC compared to PLC at POST-EX. Blood [HCO3-] was significantly higher (P < or = 0.05) during exercise for BIC compared to PLC. TIME-EX was not significantly different among treatments: BIC 287 (SEM 47.4)s; CIT 172.8 (SEM 29.7)s; and PLC 222.3 (SEM 39.7)s. Despite the fact that buffer ingestion produced favourable metabolic conditions during 30 min of high intensity steady-state exercise, a significant improvement in the subsequent maximal exercise run to exhaustion did not occur.
Publication Types:
* Clinical Trial
* Randomized Controlled Trial
* Research Support, Non-U.S. Gov't
PMID: 8851907 [PubMed - indexed for MEDLINE]
16: Eur J Appl Physiol Occup Physiol. 1999 Sep;80(4):333-6.
Related Articles, Links
Effects of chronic bicarbonate ingestion on the performance of high-intensity work.
McNaughton L, Backx K, Palmer G, Strange N.
Sports Science, Kingston University, Kingston upon Thames, Surrey, UK.
We have evaluated whether sodium bicarbonate, taken chronically (0.5 g x kg(-1) body mass) for a period of 5 days would improve the performance of eight subjects during 60 s of high-intensity exercise on an electrically braked cycle ergometer. The first test was performed prior to chronic supplementation (pre-ingestion) while the post-ingestion test took place 6 days later. A control test took place approximately 1 month after the cessation of all testing. Acid-base and metabolite data (n = 7) were measured from arterialised blood both pre- and post-exercise, as well as daily throughout the exercise period. The work completed by the subjects in the control and pre-ingestion test [21.1 (0.9) and 21.1 (0.9) MJ, respectively] was less than (P<0.05) that completed in the post-ingestion test [24.1 (0.9) MJ; F(2,21) = 3.4, P<0.05, power = 0.57]. Peak power was higher after the 5-day supplementation period (P<0.05). Ingestion of the sodium bicarbonate for a period of 5 days resulted in an increase in pH (F(5,36) = 12.5, P<0.0001, power = 1.0) over the 5-day period. The blood bicarbonate levels also rose during the trial (P<0.05) from a resting level of 22.8 (0.4) to 28.4 (1.1) mmol x l(-1) after 24 h of ingestion. In conclusion, the addition of sodium bicarbonate to a normal diet proved to be of ergogenic benefit in the performance of short-term, high-intensity work.
Publication Types:
* Clinical Trial
* Research Support, Non-U.S. Gov't
PMID: 10483803 [PubMed - indexed for MEDLINE]
Items 1 - 16 of 16
One page.
Display Show
* About Entrez
* Text Version
*
Entrez PubMed
* Overview
* Help | FAQ
* Tutorials
* New/NoteworthyNew/Noteworthy Web (RSS) Feed
* E-Utilities
*
PubMed Services
* Journals Database
* MeSH Database
* Single Citation Matcher
* Batch Citation Matcher
* Clinical Queries
* Special Queries
* LinkOut
* My NCBI
*
Related Resources
* Order Documents
* NLM Mobile
* NLM Catalog
* NLM Gateway
* TOXNET
* Consumer Health
* Clinical Alerts
* ClinicalTrials.gov
* PubMed Central
* Write to the Help Desk
* NCBI | NLM | NIH
* Department of Health & Human Services
* Privacy Statement | Freedom of Information Act | Disclaimer
"It really is all good ! My thinking only occasionally calls it differently..."
Normie
Normie
-
the lurkist
- Posts: 2240
- Joined: Wed Nov 13, 2002 2:07 pm
yeah, cus I know what lug soled shoes arepigsteak wrote:yeah, go back to your lug soled shoes kramp, and train harder
or swami...or hemp rope..or pitons...or passive only pro...or no chalk....
yup, all cheating for sure.
I am not saying that supplements are cheating, I mean, do you really know any fat people who laxatived there way to a bikini weight.How you compare may not be as important as to whom you are compared
-
anticlmber
- Posts: 3393
- Joined: Wed Jun 18, 2003 12:34 am