Table 1.
Physical characteristics of the two groups of subjects.
Table 2.
The resistance training program.
Table 3.
The endurance training program for the ER group.
Table 4.
Fiber composition, fiber area, and capillary density in biopsies from the vastus lateralis taken before (Pre) and after (Post) 7 weeks of training.
Fig 1.
Levels of proteins in the Akt signaling pathway before and after 7 weeks of training.
(A) Akt, (B) mTOR and (C) S6K1 in skeletal muscle before (Pre) and after (Post) 7 weeks of strength training only (R) or combined endurance and resistance exercise (ER). The values presented are arbitrary units normalized to the corresponding level of GAPDH and represent means ± SD for 7 subjects in the R group and 9 subjects in the ER group. For all three proteins, the ANOVA revealed a main effect of time, in addition a significant interaction (time and group) was detected for levels of Akt. Representative immunoblots from two subjects (one from each group) are shown above of each graph. *P < 0.05 for Post vs. Pre training.
Fig 2.
Expression of MAFbx and MuRF-1 before and after 7 weeks of training.
(A) mRNA and (B) protein levels of MAFbx, (C) mRNA and (D) protein levels of MuRF-1 in skeletal muscle before (Pre) and after (Post) 7 weeks of strength training only (R) or combined endurance and resistance exercise (ER). The values presented are arbitrary units normalized to the corresponding level for GAPDH and represent means ± SD for 7 subjects in the R group and 9 subjects in the ER group. The ANOVA revealed a main effect of time for total protein levels of MAFbx as well as an interaction (time and group) for mRNA expression of MuRF-1. Representative immunoblots from two subjects (one from each group) are shown above graphs C and D. *P < 0.05 for Post vs. Pre training.
Fig 3.
Relationship between changes in Akt protein and changes in fiber area.
(A) correlation between changes in the level of Akt protein and changes in type I fiber area (r = 0.61; P<0.05), (B) correlation between changes in the level of Akt protein and changes in mean fiber area (r = 0.61; P<0.05).
Fig 4.
Relationship between changes in mTOR protein and changes in fiber area.
(A) correlation between changes in the level of mTOR protein and changes in type I fiber area (r = 0.55; P<0.05), (B) correlation between changes in the level of mTOR protein and changes in mean fiber area (r = 0.55; P<0.05). One value differed considerably from the rest and was therefore regarded as an outlier and excluded from the calculations (1830; -0.16 and 1438; -0.16 in A and B, respectively).