The Pump vs. The Grind

Those people in the gym who like to "feel the burn" and get a pump tend to neglect heavy, low-rep sets. That's a mistake. But the reverse is true too. There's been renewed interest in training to get strong, which is great, but if you want to look like you lift, you need to also go light and crank out the reps.

Volumization Work

Do an endurance/volumization exercise for each body part you're wanting to build. Sure doing sets of more than 10 or 12 reps is great for increasing endurance, but you probably don't care about that. What you DO care about is the visual effect that occurs as a result of doing higher rep, burning and aching sets.

Training in this higher rep range obviously prolongs the time under tension (TUT), and it's this longer TUT that stimulates muscle growth. Since this hypertrophy resulting from high-rep sets isn't primarily coming from an increase in the size of the contractile component of the muscle (actin and myosin filaments), it's often called non-functional hypertrophy, but that's a very misleading term.

Semantics aside, when we're talking specifically about the enlargement of a muscle think of it as "volumization" – an increase in the cross-sectional area of a muscle via an increase in size and/or number of mitochondria, capillaries, enlargement of the sarcoplasmic reticulum, etc.

So How Many Reps?

Generally speaking, doing sets of 12-20 reps is perfect for stimulating muscle volumization. The cosmetic result tends to be rounder, fuller-looking muscles. Keep in mind, when your goal is larger muscles, you want to enlarge ALL components of the muscle. Failing to do so is like leaving money on the table.

Related:  11 Principles of Bodybuilding Training

Related:  The Single Best Muscle-Building Method