IGF-1 is a key signaling molecule associated with growth hormone (GH), which increases protein synthesis in skeletal muscle. Mice modified for IGF-1 expression had much faster muscle recovery. The hypertrophic effects of IGF-1 administration are well documented in animals and in studies on cell lines.
IGF-1 expression is increased in rats and in people performing strength exercises. The weightlifters had more IGF-1 from the volleyball players, moreover, the weightlifters had as many as 27% more IGF-1 from non-exercisers. However, we are constantly learning more about IGF-1 and its role in muscle growth. There are many question marks here.
It turns out that
The conclusions, probably self-administration of IGF-1 is not conducive to hypertrophy, if it is not supported by strength training. Muscle electrical stimulation is not able to replace weight training in healthy people.
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