Fig. 5. (A) The effect of tank rest or exercise training (E₁₅ and E₃₀) on overall myostatin concentration in fast muscle tissue extracts. (B) The myostatin PC was downregulated in the E₁₅ and E₃₀ groups relative to the TR group, but this was not significant. LAP concentration was also invariant between the three experimental groups. The myostatin mature peptide concentration was significantly lower in the E₁₅ and E₃₀ groups relative to the TR group (P<0.05, one-way ANOVA; ^*P<0.05, ^aP<0.1, Tukey's test). Fast muscle tissue total cellular protein extracts were Coomassie stained to demonstrate equal sample loading. Data are mean group optical density (± S.E.M.) expressed as a percentage of the TR group. TR and E₁₅, N=9; E₃₀, N=6.