Learn what a tricep extension is and how to perform it with different variations. Find out how to target your tricep muscles, get bigger arms, and stretch your triceps with this exercise. Discover the top 17 tricep extension exercises and variations to strengthen and tone your upper arm muscles. The TRX tricep extension is one of the most effective non-free-weight exercises for strengthening and toning the backs of your arms because the resistance is always relative, which is to say, based on your body weight. Best of all, like body weight triceps extensions , the TRX triceps extension is completely scalable to your ability level. Learn the proper form, techniques, and common mistakes of the tricep extension , an isolation exercise that works the back of the upper arm. Find out how to do it standing, seated, or lying down, and what equipment you need.