Building up your triceps isn't just about creating a set of 3D arms. Yes, your triceps, the three-headed muscle that runs along the back of your upper arm, will make your guns look bigger and badder and beefier than ever.

But a strong, powerful set of triceps does more than that. Strengthen your tris, and you're equipping your body to push everything from doors to people to barbells away from your body, and you're prepping your arms to brace in a straight-arm position for everything from planks to handstands. Your triceps' main job is to straighten your arm at the elbow, an action that opposes your biceps (which flex the arm at the elbow, among other things). And that straightening action is something you use daily, whenever you reach for anything, or whenever you try to get up from the ground.

There are plenty of ways to train your tris, too, although finding just the right muscle contraction isn't always easy. Remember that locking out your elbow and straightening your elbow are two different things; focus on keeping tension on your triceps and actively flexing them when you're in the straight-arm position.

Any movement that has you straightening your arm at the elbow will train your triceps, but there are plenty of ways to vary up that arm-straightening motion. Changing the angle of your arm relative to your torso can place different levels of stretch on the triceps muscle, and adding pauses, both at the top of reps and halfway through reps, can emphasize different phases of the contraction.

Not sure what you need to do to train your triceps? Consider these 17 moves.

Few bodyweight moves are as effective as the close-grip pushup. First off, this is a move you can take anywhere, a bonus triceps pump whenever you can drop and do a quick set. Secondly, you're also loading with your bodyweight—and sure, other muscles are assisting you in pressing up, but you're still getting plenty of triceps activation under load. And remember: diamonds are not your friend.

DO THIS: Set up in pushup position, with your hands just slightly narrower than shoulder-width (don't fall into the trap of thinking your hands must touch each other), hands directly below your shoulders, core tight and glutes squeezed. Lower yourself down to the floor, bending your elbows at a 45-degree angle. Make sure your elbows don't flare out to the sides; keep them locked in place. Pause, maintaining the squeeze in your core and glutes, then push back up to the original position by straightening your arms.

This bodyweight movement will look familiar to just about anyone who has tried their hand at training—after all, it appears to be as basic as finding a bench or platform and pumping yourself up and down. But if you're looking to train your triceps effectively while also protecting your shoulders, there's more that you need to know.

DO THIS: Firstly, don't even approach the bench if you have any shoulder pain or mobility issues. If your shoulders are in good shape, follow this form exactly: Sit on the bench and place your hands down with your knuckles facing outwards, to force as much external rotation as possible. Extend your legs straight out and squeeze your glutes, so you're supporting your bodyweight on your hands. Squeeze your shoulder blades together, then push your torso up high. Lower yourself down to a depth that's comfortable for you, then squeeze your triceps to extend your arms and lift yourself up.

The bench press is a great exercise to work your chest and core. But a change in grip can help expand your arms.“Placing your hands closer together makes it so your triceps have to work harder,” says Craig Ballantyne, Owner of Turbulence Training. “That can lead to new growth and more strength.” (It's also one of the 3 Secrets to a Bigger Bench Press.)

DO THIS: Grasp a barbell with an overhand grip that’s shoulder-width apart, and hold it above your sternum with arms completely straight. Lower the bar straight down, pause, and then press the bar back up to the starting position.

The skull crusher is a go-to tricep move because it gives you a chance to isolate the muscle. The lying position allows you to kill any momentum you use to cheat in other moves.

DO THIS: Put your feet flat on the floor, squeezing your glutes and keeping your core active on the bench. After you lift the bar above your chest, drive your shoulders aggressively into the bench and maintain a little bit of tension in your mid-back to prep for the exercise.

The next steps are all about isolation. Once you begin to lower the bar to your head for reps, make sure you're only moving at the elbow joint. Keep your shoulders and upper arms stable.

The JM press is a hybrid movement combining two of the best triceps builders in the game, the skull crusher and the close-grip bench press. You'll put yourself in a great position to kickstart growth using whichever implement you want, but dumbbells are a great place to start.

DO THIS: Get in a solid position on the bench. Raise the weight straight above your chest, as you would for a press—then shift your arm angle to about 92 degrees. Lower the weight so that your elbows are at your ribs, and the top heads of the weights are at your shoulders. Make sure to take your time to make sure that you stay in the proper movement path for every single rep.

This gem from MH fitness director Ebenezer Samuel, C.S.C.S., challenges you to use your triceps in unique fashion: They won't get as much stretch as some moves but they stay under constant tension from gravity and the resistance you're using for as long as you're doing reps.

Do This: Lie on a bench, holding dumbbells directly over your shoulders, abs tight. Bend your elbows so your forearms are parallel to the ground. Keeping your forearms parallel to the ground and your elbows in, slowly extend your arms overhead, never letting your forearms lose that parallel-with-the-ground position. Pause when your arms are as straight as you can get them (this may be different for different people), then slowly bring your arms back to the starting point, still keeping your forearms parallel to the ground.

One of the most basic ways to train your triceps is the pressdown, which has you keeping your elbows in line with your torso and driving your hands down while holding a band or cable. Level that move up by kneeling on the ground, engaging your abs and glutes.

Do This: Kneel on the ground, thighs in line with your torso, glutes and abs tight, shoulder blades back, grasping two ends of a resistance band. Keeping your core tight and not leaning forward, straighten your right elbow, flexing your triceps, then straighten your left elbow. Keep your left elbow straight as you do 2 reps with your right arm; reverse the movement. Maintain this pattern until you've done 10-12 total reps per arm.

What if you could train your abs and triceps at once? You get to do that on the half-bench skullcrusher, thanks to the fact that half your torso is off the bench (and thus must stay contracted to keep you level and in control).

Do This: Lie on a bench holding a dumbbell in your right hand directly above your shoulder. Shimmy over to the right side so your right glute, shoulder blade, and half your spine, and half your head are off the bench. Tighten your core. Bend at the elbow, lowering the dumbbell toward your forehead; press back up.

Here's another one that lets you smoke your abs while simultaneously giving you a vicious triceps pump.

Do This: Latch a light resistance band to a structure in front of you. Set up on plank position in front of it, core tight, and grasp the band with your right hand. You'll need to maintain a left-hand-only plank, and you'll want your hips and shoulders square, so squeeze your abs and glutes hard. Without shifting your hips, straighten your right arm, pulling the band back. Return to the start.

The triceps kickback is one of the most basic exercises for triceps development, when done correctly, forcing you to straight your arm so it's parallel with the ground.

Do This: Stand holding a dumbbell in your right arm, then hinge forward, holding something with your left arm for support. Raise your elbow so your upper arm is parallel to the ground. Keeping your upper arm parallel to the ground and without tilting your hips or shoulders, straighten your right arm, squeezing your triceps.