Kinetics of muscle carnosine decay after β-alanine supplementation: a 16-week washout study

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Yamaguchi, G.C., Nemezio, K., Schulz, M.L., Natali, J., Cesar, J.E., Riani, L.A., de Souza Gonçalves, L., Möller, G.B., Sale, C. ORCID: 0000-0002-5816-4169, de Medeiros, M.H.G., Gualano, B. and Artioli, G.G. ORCID: 0000-0001-8463-2213, 2020. Kinetics of muscle carnosine decay after β-alanine supplementation: a 16-week washout study. Medicine and Science in Sports and Exercise. ISSN 0195-9131

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Official URL: https://doi.org/10.1249/mss.0000000000002559

Abstract

Purpose: To describe the kinetics of carnosine washout in human skeletal muscle over 16 weeks.

Methods: Carnosine washout kinetics were studied in fifteen young, physically-active omnivorous men randomly assigned to take 6.4 g·d-1 of β-alanine (n=11) or placebo (PL, n=4) for 8 weeks. Muscle carnosine content (M-Carn) was determined before (PRE), immediately after (POST) and 4, 8, 12 and 16 weeks after supplementation. High-intensity exercise tests were performed at these same time points. Linear and exponential models were fitted to the washout data and the leave-one-out method was used to select the model with the best fit for M-Carn decay data. Repeated measures correlation analysis was used to assess the association between changes in M-Carn and changes in performance.

Results: M-Carn increased from PRE to POST in the β-alanine group only (+91.1±29.1%; PL:+0.04±10.1%; p<0.0001). M-Carn started to decrease after cessation of β-alanine supplementation and continued to decrease until week 16 (POST4:+59±40%; POST8:+35±39%; POST12:+18±32%; POST16:-3±24% of PRE M-Carn). From week 12 onwards, M-Carn was no longer statistically different from PRE. Both linear and exponential models displayed very similar fit and could be used to describe carnosine washout, although the linear model presented a slightly better fit. The decay in M-Carn was mirrored by a similar decay in high-intensity exercise tolerance; M-Carn was moderately and significantly correlated with TWD (r=0.505; p=0.032) and TTE (r=0.72; p<0.001).

Conclusion: Carnosine washout takes 12-16 weeks to complete, and it can be described either by linear or exponential curves. Changes in M-Carn appear to be mirrored by changes in high-intensity exercise tolerance. This information can be used to optimise β-alanine supplementation strategies.

Item Type:

Journal article

Alternative Title:

Sixteen weeks of muscle carnosine washout [running title]

Publication Title:

Medicine and Science in Sports and Exercise

Creators:

Yamaguchi, G.C., Nemezio, K., Schulz, M.L., Natali, J., Cesar, J.E., Riani, L.A., de Souza Gonçalves, L., Möller, G.B., Sale, C., de Medeiros, M.H.G., Gualano, B. and Artioli, G.G.

Publisher:

Ovid Technologies (Wolters Kluwer Health)

Date:

3 November 2020

ISSN:

0195-9131

Identifiers: