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Maximal Tension Increases MGF and IGF-1 more than Ballistic Exercise |
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Written by Robbie Durand
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Wednesday, 09 April 2008 |
MGF and IGF-1 are potent stimulators of
muscle hypertrophy; the goal of any weight training program would be too have
maximal changes in both. Researchers from Germany compared a 6 week resistance
training programming which performed 3 days a week with either maximal
contractions (bench press- 5 sets of a 3-RM) or a combination of maximal
contractions with plyometric movements.
The Combi group was the same as the maximal contraction group on Monday,
10 ballistic movements (concentric only bench press throws) with a workload of
30% of a 1-RM on Wednesday, and 10 ballistic plyo-pushups on Friday. In the
study, they found that the strength training with maximal contractions caused a
significant up-regulation of IGF- 1 and MGF gene expression, but the strength
training with combination strategy led to only a moderate increase in MGF gene
expression and no significant change in IGF-1 gene expression. It is likely
that MGF expression is more responsive to mechanical stimuli while IGF-1 may be
more to metabolic challenge. Maximal tension exercises results in greater gene
expression of growth factors than ballistic exercises.
Liu Y, Heinrichen M, Wirth K, Schmidtbleicher D, Steinacker JM. Response of growth and myogenic factors in human skeletal muscle to strength training.
Br J Sports Med. 2008 Mar 4.
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Research and Review 