Dataset Information

Effects of Sodium Bicarbonate on High-Intensity Endurance Performance in Cyclists: A Double-Blind, Randomized Cross-Over Trial.

ABSTRACT:

Background

While the ergogenic effect of sodium bicarbonate (BICA) on short-term, sprint-type performance has been repeatedly demonstrated, little is known about its effectiveness during prolonged high-intensity exercise in well-trained athletes. Therefore, this study aims to examine the influence of BICA on performance during exhaustive, high-intensity endurance cycling.

Methods

This was a single-center, double-blind, randomized, placebo-controlled cross-over study. Twenty-one well-trained cyclists (mean ± SD: age 24±8 y, BMI 21.3±1.7, VO2peak 67.3±9.8 ml·kg-1·min-1) were randomly allocated to sequences of following interventions: oral ingestion of 0.3 g·kg-1 BICA or 4 g of sodium chloride (placebo), respectively. One h after ingestion subjects exercised for 30 min at 95% of the individual anaerobic threshold (IAT) followed by 110% IAT until exhaustion. Prior to these constant load tests stepwise incremental exercise tests were conducted under both conditions to determine IAT and VO2peak. Analysis of blood gas parameters, blood lactate (BLa) and gas exchange measurements were conducted before, during and after the tests. The main outcome measure was the time to exhaustion in the constant load test.

Results

Cycling time to exhaustion was improved (p<0.05) under BICA (49.5±11.5 min) compared with placebo (45.0±9.5 min). No differences in maximal or sub-maximal measures of performance were observed during stepwise incremental tests. BICA ingestion resulted in an increased pH, bicarbonate concentration and BLa before, throughout and after both exercise testing modes.

Conclusion

The results suggest that ingestion of BICA may improve prolonged, high-intensity cycling performance.

Trial registration

German Clinical Trials Register (DRKS) DRKS00006198.

SUBMITTER: Egger F

PROVIDER: S-EPMC4262454 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Effects of Sodium Bicarbonate on High-Intensity Endurance Performance in Cyclists: A Double-Blind, Randomized Cross-Over Trial.

Egger Florian F Meyer Tim T Such Ulf U Hecksteden Anne A

PloS one 20141210 12

<h4>Background</h4>While the ergogenic effect of sodium bicarbonate (BICA) on short-term, sprint-type performance has been repeatedly demonstrated, little is known about its effectiveness during prolonged high-intensity exercise in well-trained athletes. Therefore, this study aims to examine the influence of BICA on performance during exhaustive, high-intensity endurance cycling.<h4>Methods</h4>This was a single-center, double-blind, randomized, placebo-controlled cross-over study. Twenty-one we ...[more]

PMID: 25494054

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Project description:BackgroundThe ability to sustain intense exercise seems to be partially limited by the body's capability to counteract decreases in both intra- and extracellular pH. While the influence of an enhanced buffering capacity via sodium bicarbonate (BICA) on short-term, high-intensity exercise performance has been repeatedly investigated, studies on prolonged endurance performances are comparatively rare, especially for running. The aim of the following study was to assess the ergogenic effects of an oral BICA substitution upon exhaustive intensive endurance running performance.MethodIn a double-blind randomized cross-over study, 18 trained runners (VO2peak: 61.2 ± 6.4 ml•min-1•kg-1) performed two exhaustive graded exercise tests and two constant load tests (30 main at 95% individual anaerobic threshold (IAT) followed by 110% IAT until exhaustion) after ingestion of either sodium bicarbonate (BICA) (0.3 g/kg) or placebo (4 g NaCl) diluted in 700 ml of water. Time to exhaustion (TTE) in the constant load test was defined as the main outcome measure. Throughout each test respiratory gas exchange measurements were conducted as well as determinations of heart rate, blood gases and blood lactate concentration.ResultsTTE in the constant load test did not differ significantly between BICA and placebo conditions (BICA: 39.6 ± 5.6 min, placebo: 39.3 ± 5.6 min; p = 0.78). While pH in the placebo test dropped to a slightly acidotic value two minutes after cessation of exercise (7.34 ± 0.05) the value in the BICA trial remained within the normal range (7.41 ± 0.06) (p < 0.001). In contrast, maximum running speed (Vmax) in the exhaustive graded exercise test was significantly higher with BICA (17.4 ± 1.0 km/h) compared to placebo (17.1 ± 1.0 km/h) (p = 0.009). The numerical difference in maximum oxygen consumption (VO2peak) failed to reach statistical significance (BICA: 61.2 ± 6.4 ml•min-1•kg-1, placebo: 59.8 ± 6.4 ml•min-1•kg-1; p = 0.31). Maximum blood lactate was significantly higher with BICA compared to the corresponding placebo test (BICA: 11.1 ± 2.3 mmol/l, placebo: 8.9 ± 3.0 mmol/l; p < 0.001). At the end of exercise, an acidotic pH value was found in both exhaustive graded exercise tests (p = 0.002). BICA caused gastrointestinal side effects in 15 patients.ConclusionMaximal performance was enhanced significantly after BICA administration. The ergogenic effect of BICA in the exhaustive graded exercise test can most likely be attributed to an increased anaerobic glycolysis that is reflected by an accumulation of lactate. However, TTE in prolonged high-intensity running was not improved. Even at the end of exercise no severe metabolic acidosis was found. Metabolic acidification as one of the dominant factors causing muscular fatigue should therefore be reconsidered.Trial registrationGerman Clinical Trials Register (DRKS) DRKS00011284.

Project description:BACKGROUND:Sodium bicarbonate (SB) has been proposed as an ergogenic aid, as it improves high-intensity and resistance exercise performance. However, no studies have yet investigated SB application in CrossFit. This study examined the effects of chronic, progressive-dose SB ingestion on CrossFit-like performance and aerobic capacity. METHODS:In a randomized, double-blind, cross-over trial, 21 CrossFit-trained participants were randomly allocated to 2 groups and underwent 2 trials separated by a 14-day washout period. Participants ingested either up to 150 mg?kg-1 of SB in a progressive-dose regimen or placebo for 10 days. Before and after each trial, Fight Gone Bad (FGB) and incremental cycling (ICT) tests were performed. In order to examine biochemical responses, blood samples were obtained prior to and 3 min after completing each exercise test. RESULTS:No gastrointestinal (GI) side effects were reported during the entire protocol. The overall FGB performance improved under SB by ~6.1% (p<0.001) and it was ~3.1% higher compared to post placebo (PLApost) (p = 0.040). The number of repetitions completed in each round also improved under SB (mean from baseline: +5.8% to +6.4%). Moreover, in ICT, the time to ventilatory threshold (VT) (~8:25 min SBpost vs. ~8:00 min PLApost, p = 0.020), workload at VT (~218 W SBpost vs. ~208 W PLApost, p = 0.037) and heart rate at VT (~165 bpm SBpost vs. ~161 bpm PLApost, p = 0.030) showed higher SBpost than PLApost. Furthermore, the maximum carbon dioxide production increased under SB by ~4.8% (from ~3604 mL?min-1 to ~3776 mL?min-1, p = 0.049). Pyruvate concentration and creatine kinase activity before ICT showed higher SBpost than PLApost (~0.32 mmol?L-1 vs. ~0.26 mmol?L-1, p = 0.001; ~275 U?L-1 vs. ~250 U?L-1, p = 0.010, respectively). However, the small sample size limits the wide-application of our results. CONCLUSIONS:Progressive-dose SB ingestion regimen eliminated GI side effects and improved CrossFit-like performance, as well as delayed ventilatory threshold occurrence.

Project description:Background:The aims of this study were to verify the effect of progressive-chronic and acute sodium bicarbonate (SB) supplementation on the anaerobic capacity, blood acid-base balance, and discipline-specific performance in team sports disciplines. Methods:Twenty-four trained male field hockey players completed a randomized, placebo-controlled, crossover trial of either progressive-chronic (increments from 0.05 up to 0.2?g/kg) or an acute one-off dose (0.2?g/kg) supplementation protocol. Before and after treatments, athletes completed an exercise protocol that comprised of a discipline-specific field performance test conducted between two separate Wingate anaerobic tests (WAnTs). Results:Progressive-chronic SB supplementation improved anaerobic capacity in the first bout of WAnTs, as observed based on an increase in mean power (MP: 575?±?71 vs. 602?±?67?W, p?=?0.005, ~?+?4.7%), peak power (PP: 749?±?94 vs. 777?±?96?W, p?=?0.002, ~?+?3.7%), power carry threshold (PCT) at 97%PP (727?±?91 vs. 753?±?93?W, p?=?0.002, ~?+?3.6%) and average power over PCT (739?±?94 vs. 765?±?95?W, p?=?0.001, ~?+?3.5%). Acute SB supplementation had no effect on anaerobic capacity. However, an improvement in time during discipline-specific field performance test was observed after progressive-chronic (919?±?42 vs. 912?±?27?s, p?=?0.05; ~?-?0.8%) and acute (939?±?26 vs. 914?±?22?s, p?=?0.006, ~?2.7%) SB supplementation. Acute SB supplementation also improved post-exercise parameters of acid-base balance (based on blood pH, bicarbonate concentration and base excess) compared to no supplementation or placebo. Conclusions:Our study indicates that both chronic and acute SB supplementation positively supports discipline-specific performance among field hockey athletes. Moreover, the chronic protocol supported anaerobic power indices before the inset of exercise-induced fatigue but had no significant impact afterwards. However, only the acute protocol significantly affected the buffering capacity, which can be used to determine athlete's performance during high-intensity sporting events. This study design therefore highlighted that future studies focusing on sodium bicarbonate supplementation in team sports should concentrate on the efficiency of chronic and acute supplementation in varying time frames.

Project description:The study of elite athletes provides a unique opportunity to define the upper limits of human physiology and performance. Across a variety of sports, these individuals have trained to optimize the physiological parameters of their bodies in order to compete on the world stage. To characterize endurance capacity, techniques such as heart rate monitoring, indirect calorimetry, and whole blood lactate measurement have provided insight into oxygen utilization, and substrate utilization and preference, as well as total metabolic capacity. However, while these techniques enable the measurement of individual, representative variables critical for sports performance, they lack the molecular resolution that is needed to understand which metabolic adaptations are necessary to influence these metrics. Recent advancements in mass spectrometry-based analytical approaches have enabled the measurement of hundreds to thousands of metabolites in a single analysis. Here we employed targeted and untargeted metabolomics approaches to investigate whole blood responses to exercise in elite World Tour (including Tour de France) professional cyclists before and after a graded maximal physiological test. As cyclists within this group demonstrated varying blood lactate accumulation as a function of power output, which is an indicator of performance, we compared metabolic profiles with respect to lactate production to identify adaptations associated with physiological performance. We report that numerous metabolic adaptations occur within this physically elite population (n = 21 males, 28.2 ± 4.7 years old) in association with the rate of lactate accumulation during cycling. Correlation of metabolite values with lactate accumulation has revealed metabolic adaptations that occur in conjunction with improved endurance capacity. In this population, cycling induced increases in tricarboxylic acid (TCA) cycle metabolites and Coenzyme A precursors. These responses occurred proportionally to lactate accumulation, suggesting a link between enhanced mitochondrial networks and the ability to sustain higher workloads. In association with lactate accumulation, altered levels of amino acids before and after exercise point to adaptations that confer unique substrate preference for energy production or to promote more rapid recovery. Cyclists with slower lactate accumulation also have higher levels of basal oxidative stress markers, suggesting long term physiological adaptations in these individuals that support their premier competitive status in worldwide competitions.

Dataset Information

Effects of Sodium Bicarbonate on High-Intensity Endurance Performance in Cyclists: A Double-Blind, Randomized Cross-Over Trial.

Background

Methods

Results

Conclusion

Trial registration

Publications

Effects of Sodium Bicarbonate on High-Intensity Endurance Performance in Cyclists: A Double-Blind, Randomized Cross-Over Trial.

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