Individual Responses to Creatine Supplementation on Muscular Power is Modulated by Gene Polymorphisms in Military Recruits

The aim was to explore five established SNPs (rs1815739, rs1805086, rs2700352, rs28497577, and rs28357094) that are known to modulate skeletal muscle protein kinetics in response to creatine supplementation.

A randomized, placebo-controlled, repeated measures design was used. Participants (n = 152) were randomized divided into one of two groups: CREA (20 g/day creatine monohydrate) or PLAC: (dextrose) for 7 days. SNP were assessed, and participants were classified accordingly. Before and after supplementation, anthropometrics (height and body mass) and performance measures (vertical jump, countermovement vertical jump, squat jump, abdominal crunches, and maximum push-ups) were assessed.

CREA gained more body mass than PLAC (CREA: ∆0.864 ± 0.06 kg; PLAC: ∆0.154 ± 0.07 kg, P < 0.001). In the CREA group, the presence of an A allele for the MYLK1 polymorphism was related to changes in countermovement jump height (P = 0.027; effect size [d] = 0.41) and leg power (P = 0.040, effect size [d] = 0.18). The total number of abdominal crunches after supplementation was influenced by treatments and SPP1 gene (P = 0.041). A higher number of abdominal crunches was associated with the G allele in the CREA group and the TT genotype in the PLAC group (effect size [d] = 0.04).

Collectively, short-term creatine supplementation increased body mass but was unable to alter muscle performance. However, following creatine supplementation, participants expressing A alleles in the MYLK1 polymorphism had a greater increase in jump height and leg power and participants expressing G alleles in the SPP1 gene had greater improvements in abdominal crunch performance.