Kinetics of Muscle Carnosine Decay after β-Alanine Supplementation: A 16-wk Washout Study

source extracted confidence: high 2026-04-09
#adult #carnosine #dietary-supplements #exercise #exercise-test

Kinetics of Muscle Carnosine Decay after β-Alanine Supplementation: A 16-wk Washout Study

Yamaguchi et al., 2021 | Med Sci Sports Exerc | Rct

Citation

Yamaguchi Guilherme Carvalho, Nemezio Kleiner, ... Artioli Guilherme Giannini. Kinetics of Muscle Carnosine Decay after β-Alanine Supplementation: A 16-wk Washout Study. Med Sci Sports Exerc. 2021-May-01;53(5):1079-1088. doi:10.1249/MSS.0000000000002559

Abstract

PURPOSE: This study aimed to describe the kinetics of carnosine washout in human skeletal muscle over 16 wk. METHODS: Carnosine washout kinetics were studied in 15 young, physically active omnivorous men randomly assigned to take 6.4 g·d-1 of β-alanine (n = 11) or placebo (n = 4) for 8 wk. Muscle carnosine content (M-Carn) was determined before (PRE), immediately after (POST), and 4, 8, 12, and 16 wk 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%; placebo, +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 onward, 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 total mechanical work done (r = 0.505; P = 0.032) and time to exhaustion (r = 0.72; P < 0.001). CONCLUSIONS: Carnosine washout takes 12-16 wk to complete, and it can be described either by linear or exponential curves. Changes in M-Carn seem to be mirrored by changes in high-intensity exercise tolerance. This information can be used to optimize β-alanine supplementation strategies.

Key Findings

M-Carn increased from PRE to POST in the β-alanine group only (+91.1% ± 29.1%; placebo, +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 onward, 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

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population See abstract
Sample Size 11
Age Range See abstract
Condition See abstract

MeSH Terms

  • Adult
  • Carnosine
  • Dietary Supplements
  • Exercise
  • Exercise Test
  • Exercise Tolerance
  • Humans
  • Linear Models
  • Male
  • Muscle, Skeletal
  • Time Factors
  • Young Adult
  • beta-Alanine

Evidence Classification

  • Level: Rct
  • Publication Types: Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't
  • Vertical: beta-alanine-performance

Provenance

Source extracted via PubMed E-utilities API on 2026-04-09