One of the most classic high-rep methods of blasting your biceps is something called biceps curl 21s. The simple series has you grabbing a dumbbell or barbell, doing 7 curls from the bottom to the halfway point, 7 curls from the halfway point to the top of each rep, and 7 full reps. And yes, it burns.

But there are other ways to do 21s. And there may be a better way to burn out your biceps too, says Men's Health fitness director Ebenezer Samuel, C.S.C.S. Meet the angle-change 21, a variation from Samuel that challenges your biceps in a different way. "Angle-change 21s are great," says Samuel, "because instead of working through partial range-of-motion curls, you're doing a full range each time. Now, we're changing the move by attacking different points of challenge in the ROM."

Translation: The angle-change biceps 21 burns even more, and it can spur even more growth. You're mixing three curls, says Samuel, a drag curl, meant to challenge the very top of the biceps contraction, a standard biceps dumbbell curl, and a variation that's a bit like a preacher curl. "By attacking all these curls," says Samuel, "you get a well-rounded biceps pump."

The move isn't easy, but it creates plenty of biceps challenge. And it doesn't need much equipment -- or heavy weight. "The best part," says Samuel, "is it works in any gym, whether your local big box, your house, or an hotel gym." Add it to your workouts to maximize that biceps contraction.

• Hold two dumbbells at your sides, palms facing forward. Squeeze your shoulder blades and tighten your abs.
  
• Curl the dumbbells upward, aiming to keep them in a vertical line and letting your elbows shift behind your torso. Curl as high as you can, aiming to get your forearms parallel to the ground. Pause and squeeze your biceps. Lower. Do 7 reps this way.
• Glue your elbows to your torso, aiming to keep upper arms perpendicular to the ground the whole time. Curl all the way up, never losing elbow position. Return to the bottom. Do 7 reps this way.
• Let your elbows shift in front of your torso and squeeze your shoulder blades. Maintain this position and do 7 curls.
• That's 1 set. Rest 60 to 90 seconds and do at least one more set. (Want more? Throw in a third set for even more burn).

The All-Angles Biceps 21s rep scheme is a perfect way to finish off your biceps at the end of either an arm workout or a biceps blast. "It's perfect," says Samuel, "at the end of a session because when you can't go insanely heavy. You're pushing your biceps in a different way, one that builds pump and refines your strength from multiple angles." You can also use it as a warmup move for a biceps workout, or as the final piece of a total-body circuit. Whatever you do, leave it for the end of the workout, says Samuel, because that's when it's most beneficial.

For more tips and routines from Samuel, check out our full slate of Eb and Swole workouts. If you want to try an even more dedicated routine, consider Eb's All Out Arms program.