TABLE 2.
Muscle wet tissue weight related to body weight (mean of right and left side), type I and II cross-sectional areas (CSA), nuclei per cell, and muscle protein, DNA and RNA concentrations in the right gastrocnemius muscle, and fractional synthetic rate of muscle proteins in the left quadriceps muscle after the 6 week ladder-climbing resistance training (RES) or control (CONT) period in rats that are high (HRT) or low (LRT) responders to aerobic exercise training
| HRT-RES | LRT-RES | HRT-CONT | LRT-CONT | P value | |
|---|---|---|---|---|---|
| Muscle wet tissue weight (mg g−1) | |||||
| Gastrocnemius | 4.39 (0.45) | 4.82 (0.71) | 5.03 (0.56) | 4.96 (0.70) | 0.426 |
| Soleus | 0.34 (0.03) | 0.42 (0.04) | 0.40 (0.05) | 0.44 (0.07)* | 0.043 |
| Plantaris | 0.94 (0.11) | 1.02 (0.12) | 0.98 (0.11) | 0.97 (0.14) | 0.666 |
| FHL | 1.37 (0.19) | 1.49 (0.14) | 1.51 (0.25) | 1.46 (0.18) | 0.694 |
| MQF | 7.74 (0.78) | 8.20 (0.75) | 8.61 (0.98) | 8.78 (1.16) | 0.239 |
| EDL | 0.42 (0.02) | 0.46 (0.06) | 0.45 (0.05) | 0.45 (0.06) | 0.606 |
| Triceps | 3.53 (0.39) | 4.09 (0.25) | 4.20 (0.49) | 4.01 (0.61) | 0.117 |
| Biceps | 0.66 (0.05) | 0.68 (0.08) | 0.69 (0.11) | 0.64 (0.11) | 0.810 |
| Muscle fibre characteristics | |||||
| Type land II CSA(μm2) | 4427 (494) | 3988 (594) | 4536(519) | 4045 (982) | 0.254 |
| Nuclei per cell | 3.0 (0.9) | 3.0 (0.5) | 3.2 (0.7) | 4.2 (1.6) | 0.491 |
| Muscle protein synthesis rate (% day−1) | |||||
| Myofibrillar | 2.6 (0.4) | 2.6 (0.3) | 2.7 (0.9) | 3.2 (0.7) | 0.556 |
| Sarcoplasmic | 3.8 (0.5) | 3.5 (0.3) | 3.4 (0.8) | 3.5 (1.1) | 0.540 |
| Mitochondrial | 3.1 (0.6) | 2.8 (0.5) | 2.7 (0.8) | 2.9 (0.5) | 0.927 |
| Collagen | 1.1 (0.4) | 1.1 (0.7) | 1.1 (0.5) | 1.1 (0.7) | 0.996 |
| Muscle protein, DNA and RNA concentrations | |||||
| Protein (μg mg−1) | 217.0 (38.2) | 177.7 (38.3) | ‒ | ‒ | 0.175 |
| RNA (μg mg−1) | 1.53 (0.39) | 1.45 (0.32) | ‒ | ‒ | 0.602 |
| DNA (μg mg−1) | 2.08 (0.30) | 2.00 (0.33) | ‒ | ‒ | 0.602 |
Values are expressed as the mean (SD).
*
Statistically significant (P ≤ 0.05) difference compared with the HRT-RES group. Abbreviations: CSA, cross-sectional area; EDL, extensor digitorum longus; FHL, flexor hallucis longus; and MQF, quadriceps femoris.