Another reason to keep those negatives slow and controlled.

  1. Another reason to keep those negatives slow and controlled.

    Mechanical load increases muscle IGF-I and androgen receptor mRNA concentrations in humans.

    Bamman MM, Shipp JR, Jiang J, Gower BA, Hunter GR, Goodman A, McLafferty CL Jr, Urban RJ.

    Department of Human Studies, University of Alabama at Birmingham, Birmingham, AL 35294, USA. [email protected]

    The mechanism(s) of load-induced muscle hypertrophy is as yet unclear, but increasing evidence suggests a role for locally expressed insulin-like growth factor I (IGF-I). We investigated the effects of concentric (CON) vs. eccentric (ECC) loading on muscle IGF-I mRNA concentration. We hypothesized a greater IGF-I response after ECC compared with CON. Ten healthy subjects (24.4 +/- 0.7 yr, 174.5 +/- 2.6 cm, 70.9 +/- 4.3 kg) completed eight sets of eight CON or ECC squats separated by 6-10 days. IGF-I, IGF binding protein-4 (IGFBP-4), and androgen receptor (AR) mRNA concentrations were determined in vastus lateralis muscle by RT-PCR before and 48 h after ECC and CON. Serum total testosterone (TT) and IGF-I were measured serially across 48 h, and serum creatine kinase activity (CK), isometric maximum voluntary contraction (MVC), and soreness were determined at 48 h. IGF-I mRNA concentration increased 62% and IGFBP-4 mRNA concentration decreased 57% after ECC (P < 0.05). Changes after CON were similar but not significant (P = 0.06-0.12). AR mRNA concentration increased (P < 0.05) after ECC (63%) and CON (102%). Serum TT and IGF-I showed little change. MVC fell 10% and CK rose 183% after ECC (P < 0.05). Perceived soreness was higher (P < 0.01) after ECC compared with CON. Results indicate that a single bout of mechanical loading in humans alters activity of the muscle IGF-I system, and the enhanced response to ECC suggests that IGF-I may somehow modulate tissue regeneration after mechanical damage.

    Pretty cool article. Since we know that the hGH-->IGF-1 axis is the main axis for muscle growth, it is nice to see a decrease in binding proteins and an increase in IGF-1. As you can also see, the concentric portions increase androgen receptor count slightly more however. So keep the concentrics explosive and the negatives pretty slow and controlled. Get big .
    Attached Images Attached Images  

  2. Good read!


  3. Don't see anything about the rep cadence in there. You mind posting that part?

  4. I gotta tell you I really believe there is truth to this. I have recently been doing some TUT training for the first time in my life (usually I really focus on explosive power because of sport specific reasons) and I have experienced more growth then I really thought possible in a short period of time.


  5. Yup. TUT will put some meat on ya.

  6. Definitely 5-7 negs. explosive pos


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