THE 4-D ARM WORKOUT

New science reveals the road to muscled-up bis and tris is less about #armday and more about total-body stimulus and pushing to your limits.

- EBENEZER SAMUEL, CSCS

YES, SCULPTING YOUR arms to superheroic proportions sets you on the path to perfect summer looks and helps you fill out your T-shirts. But the truest path to arm muscle isn't just about curls and pressdowns. The best way to add biceps and triceps size also involves packing on serious full-body strength, too, because contrary to bro science, it's not all about biceps curls and triceps pressdowns.

To grow any muscle, you must make it feel a significant "threat," says Pat Davidson, PhD, a former college professor turned bodybuilder and noted muscle scientist. Placing tissue under threat means pushing it to the edge of fatigue-and that happens best under heavy loads and during multi-joint movements (think squats and deadlifts). That's why, three days a week during this eight-week program, you'll emphasize the added dimension of total-body lifts.

You'll also threaten your biceps and triceps in an intense armday session once a week. But instead of basic (boring!) sets and reps, you'll use advanced techniques designed to push you to fatigue quickly. Make sure to use challenging weights during these workouts. To earn the maximum return on every session, you'll want the final rep or two of every set to feel nearly impossible to do with good form.

Combined with precise diet tips, the entire program will deliver arm size while still building the full-body muscle you need for the long haul. Enjoy the gains.

TOTAL-BODY STRENGTH

DIRECTIONS: For all three workouts, warm up with 1 minute each of jumping jacks, bodyweight reverse lunges, and plank shoulder taps, then do the moves in order. Rest 90 seconds between each set.

1. DUMBBELL ROMANIAN DEADLIFT