Search Results

You are looking at 1 - 10 of 12 items for :

  • "extracellular buffering" x
Clear All
Restricted access

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

intracellular, extracellular, and dynamic buffering systems. 13 Bicarbonate (HCO 3 − ) is an extracellular buffer that plays an important role in maintaining extracellular and intracellular pH. The blood [HCO 3 − ], and thus the extracellular buffering capacity, can be increased by ingesting sodium bicarbonate

Restricted access

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.

Restricted access

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.

Purpose:

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

Methods:

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.

Results:

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.

Conclusion:

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

Bryan Saunders, Craig Sale, Roger C. Harris and Caroline Sunderland

Purpose:

To determine whether gastrointestinal (GI) distress affects the ergogenicity of sodium bicarbonate and whether the degree of alkalemia or other metabolic responses is different between individuals who improve exercise capacity and those who do not.

Methods:

Twenty-one men completed 2 cycling-capacity tests at 110% of maximum power output. Participants were supplemented with 0.3 g/kg body mass of either placebo (maltodextrin) or sodium bicarbonate (SB). Blood pH, bicarbonate, base excess, and lactate were determined at baseline, preexercise, immediately postexercise, and 5 min postexercise.

Results:

SB supplementation did not significantly increase total work done (TWD; P = .16, 46.8 · 9.1 vs 45.6 · 8.4 kJ, d = 0.14), although magnitude-based inferences suggested a 63% likelihood of a positive effect. When data were analyzed without 4 participants who experienced GI discomfort, TWD (P = .01) was significantly improved with SB. Immediately postexercise blood lactate was higher in SB for the individuals who improved but not for those who did not. There were also differences in the preexercise-to-postexercise change in blood pH, bicarbonate, and base excess between individuals who improved and those who did not.

Conclusions:

SB improved high-intensity-cycling capacity but only with the exclusion of participants experiencing GI discomfort. Differences in blood responses suggest that SB may not be beneficial to all individuals. Magnitude-based inferences suggested that the exercise effects are unlikely to be negative; therefore, individuals should determine whether they respond well to SB supplementation before competition.

Restricted access

Nathan Philip Hilton, Nicholas Keith Leach, Melissa May Craig, S. Andy Sparks and Lars Robert McNaughton

“ergogenic window” following supplementation ( Carr et al., 2011a ), although this has yet to be confirmed. Altogether, these data suggest that ENT capsules are more effective at attenuating GI symptoms following NaHCO 3 ingestion, however DEL NaHCO 3 maximizes the extracellular buffering capacity. In this

Restricted access

Alannah K.A. McKay, Peter Peeling, Martyn J. Binnie, Paul S.R. Goods, Marc Sim, Rebecca Cross and Jason Siegler

The ingestion of sodium bicarbonate (NaHCO 3 ) is well accepted as an efficacious ergogenic aid to improve short-duration, high-intensity exercise performance. 1 The exogenous intake of NaHCO 3 acts as an extracellular buffer, raising blood pH and bicarbonate (HCO 3 − ) concentrations and

Open access

Trent Stellingwerff, Ingvill Måkestad Bovim and Jamie Whitfield

effective for them. Sodium Bicarbonate—Extracellular Buffering Sodium bicarbonate (NaHCO 3 − ) is a key extracellular buffer, which can improve performance by increasing extracellular bicarbonate (concentrations and blood pH. In doing so, the efflux of lactate and H + cations out of skeletal muscle is

Restricted access

Anne Delextrat, Sinead Mackessy, Luis Arceo-Rendon, Aaron Scanlan, Roger Ramsbottom and Julio Calleja-Gonzalez

muscle and its efflux into the blood ( Saraslanidis et al., 2009 ). This suggests that participants were able to increase their speed thanks to a less acidic intracellular environment brought about by the extracellular buffering of H + ions by HCO 3 − . However, when longer protocols are used

Restricted access

Rodrigo dos Santos Guimarães, Alcides Correa de Morais Junior, Raquel Machado Schincaglia, Bryan Saunders, Gustavo Duarte Pimentel and João Felipe Mota

, P.H.L. , Oliveira , L.F. , McNaughton , L.R. , & Saunders , B. ( 2018 ). Time to optimize supplementation: modifying factors influencing the individual responses to extracellular buffering agents . Frontiers in Nutrition, 5 ( 5 ), 35 . PubMed ID: 29868599 doi:10.3389/fnut.2018.00035 10

Open access

Peter Peeling, Martyn J. Binnie, Paul S.R. Goods, Marc Sim and Louise M. Burke

-015-0087-6 Lancha Junior , A.H. , de Painelli , V.S. , Saunders , B. , & Artioli , G.G. ( 2015 ). Nutritional strategies to modulate intracellular and extracellular buffering capacity during high-intensity exercise . Sports Medicine, 45 ( Suppl. 1 ), 71 – 81 . doi:10.1007/s40279-015-0397-5 10.1007/s