Search Results

You are looking at 1 - 10 of 50 items for :

  • "alkalosis" x
  • Refine by Access: All Content x
Clear All
Open access

A Comparison of Sodium Citrate and Sodium Bicarbonate Ingestion: Blood Alkalosis and Gastrointestinal Symptoms

Charles S. Urwin, Rodney J. Snow, Dominique Condo, Rhiannon M.J. Snipe, Glenn D. Wadley, Lilia Convit, and Amelia J. Carr

such as 4,000 m cycling, 1,500 m running, and 2,000 m rowing can aim to minimize the inhibitory effect of acidosis by inducing blood alkalosis (increased blood pH and [HCO 3 − ]) prior to their event ( Maughan et al., 2018 ). Blood alkalosis can be induced by sodium citrate (SC) or sodium bicarbonate

Restricted access

Factors Influencing Blood Alkalosis and Other Physiological Responses, Gastrointestinal Symptoms, and Exercise Performance Following Sodium Citrate Supplementation: A Review

Charles S. Urwin, Rodney J. Snow, Dominique Condo, Rhiannon Snipe, Glenn D. Wadley, and Amelia J. Carr

( Maughan et al., 2018 ) that induce blood alkalosis (increased blood pH and blood bicarbonate concentration ([HCO 3 − ]); Maughan et al., 2004 ). The ergogenic potential of these supplements is often attributed to an ability to delay the onset of intramuscular acidosis (decreased muscle pH) during

Restricted access

Induced Alkalosis and Gastrointestinal Symptoms After Sodium Citrate Ingestion: a Dose-Response Investigation

Charles S. Urwin, Dan B. Dwyer, and Amelia J. Carr

Sodium citrate induces alkalosis and can provide a performance benefit in high-intensity exercise. Previous investigations have been inconsistent in the ingestion protocols used, in particular the dose and timing of ingestion before the onset of exercise. The primary aim of the current study was to quantify blood pH, blood bicarbonate concentration and gastrointestinal symptoms after ingestion of three doses of sodium citrate (500 mg⋅kg-1, 700 mg⋅kg-1 and 900 mg⋅kg-1). Thirteen participants completed four experimental sessions, each consisting of a different dose of sodium citrate or a taste-matched placebo solution. Blood pH and blood bicarbonate concentration were measured at 30-min intervals via analysis of capillary blood samples. Gastrointestinal symptoms were also monitored at 30-min intervals. Statistical significance was accepted at a level of p < .05. Both measures of alkalosis were significantly greater after ingestion of sodium citrate compared with placebo (p < .001). No significant differences in alkalosis were found between the three sodium citrate doses (p > .05). Peak alkalosis following sodium citrate ingestion ranged from 180 to 212 min after ingestion. Gastrointestinal symptoms were significantly higher after sodium citrate ingestion compared with placebo (p < .001), while the 900 dose elicited significantly greater gastrointestinal distress than 500 mg⋅kg-1 (p = .004). It is recommended that a dose of 500 mg⋅kg-1 of sodium citrate should be ingested at least 3 hr before exercise, to achieve peak alkalosis and to minimize gastrointestinal symptoms before and during exercise.

Restricted access

Effect of Warm-Up and Sodium Bicarbonate Ingestion on 4-km Cycling Time-Trial Performance

William H. Gurton, Steve H. Faulkner, and Ruth M. James

agents exist that elicit a metabolic alkalosis which improves the capacity to buffer H + during high-intensity exercise. Perhaps the most well-established and extensively researched is sodium bicarbonate (NaHCO 3 ). 4 This nutritional supplement enhances the extracellular buffering response by

Restricted access

The Effect of Sodium Bicarbonate Supplementation on the Decline in Gross Efficiency During a 2000-m Cycling Time Trial

Anna E. Voskamp, Senna van den Bos, Carl Foster, Jos J. de Koning, and Dionne A. Noordhof

were co-ingested with a meal containing 1.5-g carbohydrate/kg BM and 7-mL/kg BM of fluid, which optimizes blood alkalosis and diminishes the incidence of gastrointestinal (GI) symptoms. 22 Before ingestion of the meal and the supplements, subjects completed a validated GI-distress questionnaire. 26

Restricted access

Induced Alkalosis and Caffeine Supplementation: Effects on 2,000-m Rowing Performance

Amelia J. Carr, Christopher J. Gore, and Brian Dawson


The purpose of this investigation was to determine the effect of ingested caffeine, sodium bicarbonate, and their combination on 2,000-m rowing performance, as well as on induced alkalosis (blood and urine pH and blood bicarbonate concentration [HCO3−]), blood lactate concentration ([La]), gastrointestinal symptoms, and rating of perceived exertion (RPE).


In a double-blind, crossover study, 8 well-trained rowers performed 2 baseline tests and 4 × 2,000-m rowing-ergometer tests after ingesting 6 mg/kg caffeine, 0.3 g/kg body mass (BM) sodium bicarbonate, both supplements combined, or a placebo. Capillary blood samples were collected at preingestion, pretest, and posttest time points. Pairwise comparisons were made between protocols, and differences were interpreted in relation to the likelihood of exceeding the smallestworthwhile- change thresholds for each variable. A likelihood of >75% was considered a substantial change.


Caffeine supplementation elicited a substantial improvement in 2,000-m mean power, with mean (± SD) values of 354 ± 67 W vs. placebo with 346 ± 61 W. Pretest [HCO3−] reached 29.2 ± 2.9 mmol/L with caffeine + bicarbonate and 29.1 ± 1.9 mmol/L with bicarbonate. There were substantial increases in pretest [HCO3−] and pH and posttest urine pH after bicarbonate and caffeine + bicarbonate supplementation compared with placebo, but unclear performance effects.


Rowers’ performance in 2,000-m efforts can improve by ~2% with 6 mg/kg BM caffeine supplementation. When caffeine is combined with sodium bicarbonate, gastrointestinal symptoms may prevent performance enhancement, so further investigation of ingestion protocols that minimize side effects is required.

Restricted access

Influence of Pre-Exercise Acidosis and Alkalosis on the Kinetics of Acid-Base Recovery Following Intense Exercise

Robert Robergs, Keith Hutchinson, Shonn Hendee, Sean Madden, and Jason Siegler

The purpose of this study was to measure the recovery kinetics of pH and lactate for the conditions of pre-exercise acidosis, alkalosis, and placebo states. Twelve trained male cyclists completed 3 exercise trials (110% workload at VO2max), ingesting either 0.3 g/kg of NH4Cl (ACD), 0.2 g/kg of Na+HCO3 - and 0.2 g/kg of sodium citrate (ALK), or a placebo (calcium carbonate) (PLAC). Blood samples (heated dorsal hand vein) were drawn before, during, and after exercise. Exercise-induced acidosis was more severe in the ACD and PLAC trials (7.15 ± 0.06, 7.21 ± 0.07, 7.16 ± 0.06, P < 0.05, for ACD, ALK, PLAC, respectively). Recovery kinetics for blood pH and lactate, as assessed by the monoexponential slope constant, were not different between trials (0.057 ± 0.01, 0.050 ± 0.01, 0.080 ± 0.02, for ACD, ALK, PLAC, respectively). Complete recovery of blood pH from metabolic acidosis can take longer than 45 min. Such a recovery profile is nonlinear, with 50% recovery occurring in approximately 12 min. Complete recovery of blood lactate can take longer than 60 min, with 50% recovery occurring in approximately 30 min. Induced alkalosis decreases metabolic acidosis and improves pH recovery compared to acidodic and placebo conditions. Although blood pH and lactate are highly correlated during recovery from acidosis, they recover at significantly different rates.

Restricted access

Does Sodium-Bicarbonate Ingestion Improve Simulated Judo Performance?

Guilherme Giannini Artioli, Bruno Gualano, Desiré Ferreira Coelho, Fabiana Braga Benatti, Alessandra Whyte Gailey, and Antonio Herbert Lancha Jr.

The aim of the present study was to investigate whether pre exercise sodium-bicarbonate ingestion improves judo-related performance. The study used 2 different protocols to evaluate performance: 3 bouts of a specific judo test (n = 9) and 4 bouts of the Wingate test for upper limbs (n = 14). In both protocols athletes ingested 0.3 g/kg of sodium bicarbonate or placebo 2 h before the tests. Blood samples were collected to determine lactate level, and levels of perceived exertion were measured throughout the trials. The study used a double-blind, counterbalanced, crossover design. Ingestion of sodium bicarbonate improved performance in Bouts 2 and 3 of Protocol 1 (P < 0.05), mean power in Bouts 3 and 4 of Protocol 2 (P < 0.05), and peak power in Bout 4 of Protocol 2 (P < 0.05). Ingestion of bicarbonate increased lactate concentration in Protocol 1 (P < 0.05) but not in Protocol 2. Ratings of perceived exertion did not differ between treatments. In conclusion, sodium bicarbonate improves judo-related performance and increases blood lactate concentration but has no effect on perceived exertion.

Restricted access

Effect of Sodium Bicarbonate Supplementation on 2000-m Rowing Performance

Ruth M. Hobson, Roger C. Harris, Dan Martin, Perry Smith, Ben Macklin, Kirsty J. Elliott-Sale, and Craig Sale

The ability to buffer H+ could be vital to exercise performance, as high concentrations of H+ contribute to the development of fatigue.


The authors examined the effect of sodium bicarbonate (SB) supplementation on 2000-m rowing-ergometer performance.


Twenty male rowers (age 23 ± 4 y, height 1.85 ± 0.08 m, mass 82.5 ± 8.9 kg, 2000-m personal-best time 409 ± 16 s) completed two 2000-m rowing-ergometer time trials, separated by 48 h. Participants were supplemented before exercise with 0.3 g/kg body mass of SB or a placebo (maltodextrin; PLA). The trials were conducted using a double-blinded, randomized, counterbalanced crossover study design. Time to complete the 2000-m and time taken for each 500-m split were recorded. Blood lactate, bicarbonate, pH, and base excess were determined preexercise, immediately postexercise, and 5 min postexercise. Performance data were analyzed using paired t tests, as well as magnitude-based inferences; hematological data were analyzed using a repeated-measures ANOVA.


Using paired t tests, there was no benefit of SB over PLA (P = .095). However, using magnitude-based inferences there was a likely beneficial effect of SB compared with PLA (PLA 412.0 ± 15.1 s, SB 410.7 ± 14.9 s). Furthermore, SB was 0.5 ± 1.2 s faster than PLA in the third 500 m (P = .035; possibly beneficial) and 1.1 ± 1.7 s faster in the fourth 500 m (P = .004; very likely beneficial). All hematological data were different between SB and PLA and were different from preexercise to postexercise.


SB supplementation is likely to be beneficial to the performance of those competing in 2000-m rowing events, particularly in the second half of the event.

Restricted access

The Effects of Two Different Doses of Calcium Lactate on Blood pH, Bicarbonate, and Repeated High-Intensity Exercise Performance

Vitor de Salles Painelli, Rafael Pires da Silva, Odilon Marques de Oliveira Junior, Luana Farias de Oliveira, Fabiana Braga Benatti, Tobias Rabelo, João Paulo Limongi França Guilherme, Antonio Herbert Lancha Junior, and Guilherme Giannini Artioli

We investigated the effects of low- and high-dose calcium lactate supplementation on blood pH and bicarbonate (Study A) and on repeated high-intensity performance (Study B). In Study A, 10 young, physically active men (age: 24 ± 2.5 years; weight: 79.2 ± 9.45 kg; height: 1.79 ± 0.06 m) were assigned to acutely receive three different treatments, in a crossover fashion: high-dose calcium lactate (HD: 300 mg·kg−1 body mass), low-dose calcium lactate (LD: 150 mg·kg−1 body mass) and placebo (PL). During each visit, participants received one of these treatments and were assessed for blood pH and bicarbonate 0, 60, 90, 120, 150, 180, and 240 min following ingestion. In Study B, 12 young male participants (age: 26 ± 4.5 years; weight: 82.0 ± 11.0 kg; height: 1.81 ± 0.07 m) received the same treatments of Study A. Ninety minutes after ingestion, participants underwent 3 bouts of the upper-body Wingate test and were assessed for blood pH and bicarbonate 0 and 90 min following ingestion and immediately after exercise. In Study A, both HD and LD promoted slight but significant increases in blood bicarbonate (31.47 ± 1.57 and 31.69 ± 1.04 mmol·L−1, respectively) and pH levels (7.36 ± 0.02 and 7.36 ± 0.01, respectively), with no effect of PL. In Study B, total work done, peak power, mean power output were not affected by treatments. In conclusion, low- and high-dose calcium lactate supplementation induced similar, yet very discrete, increases in blood pH and bicarbonate, which were not sufficiently large to improve repeated high-intensity performance.