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

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

The influence of n-3PUFA supplementation on muscle mass and strength in adults: A systematic review.

In recent years, studies have shown that supplementation of omega 3 fatty acids (n-3 PUFA) could be associated with increased rates of muscle protein synthesis, and may contribute to the greater gain in muscle mass and strength chronically. However, unlike studies with older adults, studies in young adults are contradictory, and while some observe greater gains in muscle mass and strength in response to n-3PUFA supplementation in healthy adults, others do not demonstrate these effects. The aim of this systematic review is to evaluate the current evidence of the efects of n-3pUFA supplementation on muscle mass and strenght in adults