Figure 3. Muscle contractile phenotype and function in HIT and HIT+β₂A.

Effect of 4 weeks of high intensity training with (HIT+β₂A, n = 12) and without (HIT, n = 9) daily inhalation of terbutaline (4 mg day⁻¹) on outcomes related to contractile phenotype and function in trained men. A, heat map of mean Z‐score changes of the proteome related to the cytoskeleton and contractile phenotype in HIT and HIT+β₂A, as well as between‐group interaction (HIT+β₂A – HIT). B, Gaussian fit of frequency distribution of discriminant canonical function score of within‐group changes in the proteins listed in A using a principal component‐discriminant analysis (PCA‐DA) of the eight first principal components that explained 80% of the variance. C, mean (±95% CI) change in myosin heavy chain (MHC) isoform distribution. D, PCA of intensity (log₂‐expression) of myosin isoforms determined by proteomics (open circles) and MHC isoform distribution determined immunohistochemically (purple circles). E–K, mean (±95% CI) values for muscle mass and contractile properties. CSA, cross‐sectional area. ^#Between‐group interaction (P ≤ 0.05). ^##Between‐group interaction (P ≤ 0.01). ^*Within‐group difference from pre (P ≤ 0.05). ^**Within‐group difference from pre (P ≤ 0.01).