Here's the deal. There are 2 ways to create size. One is by the increase in size of contractile proteins (the things that actually make your muscles work) the other by increasing the volume of the sarcoplasm, which is all the other stuff (mitochondria, nuclei, etc for all who have had bio classes). To increase the contractile proteins, you lift heavy which requires lower reps. To increase the volume of the fluids, the sarcoplasm, you lift higher volume (more sets, higher reps, 8-12ish) which requires a lighter weight to do so. Most bodybuilders do a bit of both. |