Pushups with your hands set directly under your shoulders work all of the triceps.
Although the triceps brachii muscle at the back of your upper arms features three heads, they work together when extending your elbows. However, because of the angle your shoulders are in when you're performing dips, close-grip bench presses and triceps pushdowns, each of the three heads is in a position where it can contribute to the extension of your elbows.
Although the triceps has three heads, this muscle contracts as a whole. Include dips, bench press and pushdowns to strengthen your triceps.
Perform Dips Correctly
Dips are a challenging exercise that require you to lift up your own body weight, but they can be modified for those who find the traditional version too difficult. Dips are most commonly performed using parallel bars. Stand in between the bars and grip each one with your hands. Lift your body off the floor so that your arms are straight, placing all your body weight on your hands, to get to the starting position. Bend your elbows to lower your body toward the floor. Your elbows should move directly behind you instead of out to your sides. Once your elbows are bent to 90 degrees, extend them fully to complete one rep.
Modify Your Dips
To modify dips, perform them on a bench instead of parallel bars. Sit perpendicular on the bench and place your hands on the edge on either side of your hips. Extend your legs out in front of you and either place your heels onto a second bench or rest your heels on the floor. Lift your hips off the bench, placing all your weight onto your hands. Bend your elbows to lower your hips toward the floor, continuing until your elbows are bent to 90 degrees. Straighten your elbows to complete one rep.
Try Close-Grip Bench Presses
Close-grip bench presses require the use of a flat bench and a weighted barbell. Lie on your back on the bench and grip the bar so that your hands are shoulder-width apart. Bend your elbows and keep them close to your torso to lower the barbell toward your chest. Extend your arms to lift the barbell back to the starting position. Close-grip pushups, which require the same movement at the shoulders and elbows as close-grip bench presses, also work all three heads of the triceps.
Include Triceps Pushdowns
The triceps pushdown exercise requires the use of a cable pulley unit. First set the pulley so that it's at a high position so that the end of the pulley is at least at shoulder height. Attach a straight bar attachment to the end of the cable pulley. Stand facing the unit and grip the straight bar using an overhand grip. Hold your elbows into the sides of your torso as you extend your arms and lower the bar toward the front of your thighs. Bend your elbows to control the bar back up and then repeat.