Barbell curls. Preacher curls. Extensions. Pressdowns. On arms day, these are a few of our favorite things. But why do so many guys use single-joint isolation exercises for biceps and triceps, and then bombard larger muscle groups, such as the chest, back and quads, with an array of multi-joint moves that allow for more weight? Is it possible to use that same strategy on your arms? Justin Grinnell, C.S.C.S., owner of State of Fitness, believes it is.

“When athletes think about developing ripped arms, they immediately think of isolation exercises, such as biceps curls and triceps pressdowns,” he says. “While isolation movements are great when trying to add some detail to a muscle group, for overall mass and strength gains, compound movements will always trump isolation movements.”

Grinnell says that multi-joint moves and heavier weight loads will lead to a greater release of your body’s natural growth hormone, testosterone, and IGF-1. Collectively, these hormones work to help you add size—everywhere. That includes your pipes. Just train, feed, and repeat. Here are Grinnell’s four moves to get you going.