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Is individualization of sodium bicarbonate ingestion based on time to peak necessary?

Farias de Oliveira, Luana; Saunders, Bryan; Yamaguchi, Guilherme; Swinton, Paul; Giannini Artioli, Guilherme


Luana Farias de Oliveira

Bryan Saunders

Guilherme Yamaguchi

Guilherme Giannini Artioli


Purpose: To describe the reliability of blood bicarbonate pharmacokinetics in response to sodium bicarbonate (SB) supplementation across multiple occasions and assess, using putative thresholds, whether individual variation indicated a need for individualised ingestion timings. Methods: Thirteen men (age 27±5 y; body mass (BM) 77.4±10.5 kg; height 1.75±0.06 m) ingested 0.3 g·kg-1BM SB in gelatine capsules on 3 occasions. One hour after a standardised meal, venous blood was obtained before and every 10 min following ingestion for 3 h, then every 20 min for a further hour. Time-to-peak (Tmax), absolute-peak (Cmax), absolute-peak-change (ΔCmax) and area under the curve (AUC) were analysed using mixed models, intraclass correlation coefficient (ICC), coefficient of variation (CV) and typical error. Individual variation in pharmacokinetic responses was assessed using Bayesian simulation with multilevel models with random intercepts. Results: No significant differences between sessions were shown for blood bicarbonate regarding Cmax, ΔCmax or AUC (p>0.05), although Tmax occurred earlier in SB2 (127±36 min) than in SB1 (169±54 min, p=0.0088) and SB3 (159±42 min, p=0.05). ICC, CV and typical error showed moderate to poor reliability. Bayesian modelling estimated that >80% of individuals from the population experience elevated blood bicarbonate levels above + 5 mmol∙L-1 between 75-240 min after ingestion, and between 90-225 min above +6 mmol∙L-1. Conclusion: Assessing SB supplementation using discrete values showed only moderate reliability at the group level, and poor reliability at the individual level, while Tmax was not reproducible. However, when analysed as modelled curves, a 0.3 g·kg-1BM dose was shown to create a long-lasting window of ergogenic potential, challenging the notion that SB ingestion individualised to time-to-peak is a necessary strategy, at least when SB is ingested in capsules.


FARIAS DE OLIVEIRA, L., SAUNDERS, B., YAMAGUCHI, G., SWINTON, P. and GIANNINI ARTIOLI, G. 2020. Is individualization of sodium bicarbonate ingestion based on time to peak necessary? Medicine and science in sports and exercise [online], 52(8), pages 1801-1808. Available from:

Journal Article Type Article
Acceptance Date Feb 12, 2020
Online Publication Date Feb 25, 2020
Publication Date Aug 31, 2020
Deposit Date Feb 13, 2020
Publicly Available Date Feb 26, 2021
Journal Medicine and science in sports and exercise
Print ISSN 0195-9131
Electronic ISSN 1530-0315
Publisher Lippincott, Williams & Wilkins
Peer Reviewed Peer Reviewed
Volume 52
Issue 8
Pages 1801-1808
Keywords Time-course; Ergogenic supplement; Bioavailability; Blood bicarbonate; Reproducibility
Public URL


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