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Luana Farias de Oliveira, Bryan Saunders, and Guilherme Giannini Artioli

Sodium bicarbonate (SB) is an ergogenic supplement shown to improve high-intensity exercise via increased blood bicarbonate buffering. Substantial amounts of the ingested bicarbonate are neutralized in the stomach. Bariatric surgery results in a small gastric pouch which dramatically reduces exposure time of any ingested food in the stomach. The aim of this study was to examine the pharmacokinetics of orally ingested SB in a postgastric bypass individual to determine the magnitude of changes in blood bicarbonate and associated side effects. We hypothesized that SB supplementation in a gastric bypass model would result in greater blood bicarbonate increases and fewer side effects than in healthy individuals due to minimal bicarbonate losses in the stomach. One postbariatric male ingested 0.3 g/kg·body mass of SB on three occasions (SB1, SB2, and SB3) and 0.3 g/kg·body mass of placebo on a further occasion. Blood bicarbonate was determined before and every 10 min following supplement ingestion for 3 hr and then every 20 min for a further 1 hr. Side effects were reported using an adapted questionnaire at identical time points. Maximal increases in blood bicarbonate with SB were +20.0, +15.2, and +12.6 mM, resulting in maximal bicarbonate concentrations of 42.8, 39.3, and 36.2 mM. Area under the curve was SB1: 8,328 mM/min; SB2: 7,747 mM/min; SB3: 7,627 mM/min, and 6,436 mM/min for placebo. Side effects with SB were scarce. Maximal bicarbonate increases were well above those shown previously, with minimal side effects, indicative of minimal neutralization of bicarbonate in the stomach. The large increases in circulating bicarbonate and minimal side effects experienced by our postgastric surgery bypass patient are indicative that minimizing neutralization of bicarbonate in the stomach, as would occur with enteric coated capsules, may optimize SB supplementation and thus warrants investigation.

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Rebecca Louise Jones, Trent Stellingwerff, Guilherme Giannini Artioli, Bryan Saunders, Simon Cooper, and Craig Sale

To defend against hydrogen cation accumulation and muscle fatigue during exercise, sodium bicarbonate (NaHCO3) ingestion is commonplace. The individualized dose-response relationship between NaHCO3 ingestion and blood biochemistry is unclear. The present study investigated the bicarbonate, pH, base excess and sodium responses to NaHCO3 ingestion. Sixteen healthy males (23 ± 2 years; 78.6 ± 15.1 kg) attended three randomized order-balanced, nonblinded sessions, ingesting a single dose of either 0.1, 0.2 or 0.3 g·kg-1BM of NaHCO3 (Intralabs, UK). Fingertip capillary blood was obtained at baseline and every 10 min for 1 hr, then every 15 min for a further 2 hr. There was a significant main effect of both time and condition for all assessed blood analytes (p ≤ .001). Blood analyte responses were significantly lower following 0.1 g·kg-1BM compared with 0.2 g·kg-1BM; bicarbonate concentrations and base excess were highest following ingestion of 0.3 g·kg-1BM (p ≤ .01). Bicarbonate concentrations and pH significantly increased from baseline following all doses; the higher the dose the greater the increase. Large interindividual variability was shown in the magnitude of the increase in bicarbonate concentrations following each dose (+2.0–5; +5.1–8.1; and +6.0–12.3 mmol·L-1 for 0.1, 0.2 and 0.3 g·kg-1BM) and in the range of time to peak concentrations (30–150; 40–165; and 75–180 min for 0.1, 0.2 and 0.3 g·kg-1BM). The variability in bicarbonate responses was not affected by normalization to body mass. These results challenge current practices relating to NaHCO3 supplementation and clearly show the need for athletes to individualize their ingestion protocol and trial varying dosages before competition.

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Rebecca L. Jones, Trent Stellingwerff, Paul Swinton, Guilherme Giannini Artioli, Bryan Saunders, and Craig Sale

This study determined the influence of a high- (HI) versus low-intensity (LI) cycling warm-up on blood acid-base responses and exercise capacity following ingestion of sodium bicarbonate (SB; 0.3 g/kg body mass) or a placebo (PLA; maltodextrin) 3 hr prior to warm-up. Twelve men (21 ± 2 years, 79.2 ± 3.6 kg body mass, and maximum power output [W max] 318 ± 36 W) completed a familiarization and four double-blind trials in a counterbalanced order: HI warm-up with SB, HI warm-up with PLA, LI warm-up with SB, and LI warm-up with PLA. LI warm-up was 15 min at 60% W max, while the HI warm-up (typical of elites) featured LI followed by 2 × 30 s (3-min break) at W max, finishing 30 min prior to a cycling capacity test at 110% W max. Blood bicarbonate and lactate were measured throughout. SB supplementation increased blood bicarbonate (+6.4 mmol/L; 95% confidence interval, CI [5.7, 7.1]) prior to greater reductions with HI warm-up (−3.8 mmol/L; 95% CI [−5.8, −1.8]). However, during the 30-min recovery, blood bicarbonate rebounded and increased in all conditions, with concentrations ∼5.3 mmol/L greater with SB supplementation (p < .001). Blood bicarbonate significantly declined during the cycling capacity test at 110%W max with greater reductions following SB supplementation (−2.4 mmol/L; 95% CI [−3.8, −0.90]). Aligned with these results, SB supplementation increased total work done during the cycling capacity test at 110% W max (+8.5 kJ; 95% CI [3.6, 13.4], ∼19% increase) with no significant main effect of warm-up intensity (+0.0 kJ; 95% CI [−5.0, 5.0]). Collectively, the results demonstrate that SB supplementation can improve HI cycling capacity irrespective of prior warm-up intensity, likely due to blood alkalosis.

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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.

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Gabriel Perri Esteves, Paul Swinton, Craig Sale, Ruth M. James, Guilherme Giannini Artioli, Hamilton Roschel, Bruno Gualano, Bryan Saunders, and Eimear Dolan

Currently, little is known about the extent of interindividual variability in response to beta-alanine (BA) supplementation, nor what proportion of said variability can be attributed to external factors or to the intervention itself (intervention response). To investigate this, individual participant data on the effect of BA supplementation on a high-intensity cycling capacity test (CCT110%) were meta-analyzed. Changes in time to exhaustion (TTE) and muscle carnosine were the primary and secondary outcomes. Multilevel distributional Bayesian models were used to estimate the mean and SD of BA and placebo group change scores. The relative sizes of group SDs were used to infer whether observed variation in change scores were due to intervention or non-intervention-related effects. Six eligible studies were identified, and individual data were obtained from four of these. Analyses showed a group effect of BA supplementation on TTE (7.7, 95% credible interval [CrI] [1.3, 14.3] s) and muscle carnosine (18.1, 95% CrI [14.5, 21.9] mmol/kg DM). A large intervention response variation was identified for muscle carnosine (σIR = 5.8, 95% CrI [4.2, 7.4] mmol/kg DM) while equivalent change score SDs were shown for TTE in both the placebo (16.1, 95% CrI [13.0, 21.3] s) and BA (15.9, 95% CrI [13.0, 20.0] s) conditions, with the probability that SD was greater in placebo being 0.64. In conclusion, the similarity in observed change score SDs between groups for TTE indicates the source of variation is common to both groups, and therefore unrelated to the supplement itself, likely originating instead from external factors such as nutritional intake, sleep patterns, or training status.

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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.