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Individual participant data meta-analysis provides no evidence of individual response variation in individuals supplementing with beta-alanine.

Esteves, Gabriel Perri; Swinton, Paul; Sale, Craig; James, Ruth; Artioli, Guilherme Giannini; Roschel, Hamilton; Gualano, Bruno; Saunders, Bryan; Dolan, Eimear

Authors

Gabriel Perri Esteves

Craig Sale

Ruth James

Guilherme Giannini Artioli

Hamilton Roschel

Bruno Gualano

Bryan Saunders

Eimear Dolan



Abstract

Currently, little is known about the extent of inter-individual variability in response to beta-alanine (BA) supplementation, nor what proportion of said variability can be attributed to external factors, or to the intervention itself (intervention response). To investigate this, individual participant data on the effect of BA supplementation on a high intensity cycling capacity test (CCT110%) were meta-analysed. Changes in time to exhaustion (TTE) and muscle carnosine (MCarn) were the primary and secondary outcomes. Multi-level distributional Bayesian models were used to estimate the mean and standard deviation of BA and placebo (PLA) group change scores. The relative sizes of group standard deviations were used to infer whether observed variation in change scores were due to intervention or non-intervention related effects. Six eligible studies were identified, and individual data were obtained from four of these. Analyses showed a group effect of BA supplementation on TTE (7.7[95%CrI:1.3 to 14.3 s]) and MCarn (18.1[95%CrI:14.5 to 21.9 mmol·kgDM-1]). A large intervention response variation was identified for MCarn (σ_IR= 5.8 [95%CrI: 4.2 to 7.4 mmol·kgDM-1]); however, equivalent change score standard deviations were shown for PLA (16.1[95%CrI:13.0 to 21.3 s]) and BA (15.9[95%CrI:13.0 to 20.0 s] conditions, with the probability that standard deviation was greater in PLA being 0.64. In conclusion, the similarity in observed change score standard deviations between groups for TTE indicates the source of variation is common and therefore unrelated to BA supplementation, likely originating instead from external factors, which may include, for example, nutritional intake, sleep patterns or training status.

Citation

ESTEVES, G.P., SWINTON, P., SALE, C., JAMES, R., ARTIOLI, G.G., ROSCHEL, H., GUALANO, B., SAUNDERS, B. and DOLAN, E. [2021]. Individual participant data meta-analysis provides no evidence of individual response variation in individuals supplementing with beta-alanine. International journal of sport nutrition and exercise metabolism, (accepted).

Journal Article Type Article
Acceptance Date Apr 6, 2021
Deposit Date Apr 6, 2021
Journal International journal of sport nutrition and exercise metabolism
Print ISSN 1526-484X
Electronic ISSN 1543-2742
Publisher Human Kinetics
Peer Reviewed Peer Reviewed
Keywords β-Alanine; Performance; Exercise capacity; Individual response; Carnosine; Supplement
Public URL https://rgu-repository.worktribe.com/output/1299512