If you pushed most people on their answer, many would opt for the often used rope pushdown as the true king. It's ability to zone in and create an extreme burn in the arms is truly uncanny.

But according to the latest science, there is one clear winner in this category and it is none of the above!

But if you follow bodybuilding, you will know that there is one move which was conveniently left off the list above. Triceps kickbacks. That's right, the one you usually leave until the end of your workout or, even worse, dismiss as an exercise intended for the girls. Surely there is some error.

In fact, no mistake was made.

Not only did they prove themselves to be the true kings of the jungle when it came to arm exercises, they were confirmed to be streets ahead of their more popular main rivals.

In 2012, researchers from the University of South Carolina Upstate set out to discover the facts behind which exercise isolated the muscle more than any other. They compared several of the best known moves, putting subjects through an intense arm training routine and taking the key factors taking place inside the muscle.

When compared to the much more popular rope pushdown, kickbacks catapulted muscle activity in the long head of the triceps by 20%. But that was not all. In the lateral head, the one that gives your arms that much thought-after width most guys try to achieve in the gym, muscle activity soared up by an extra 50%.

All of this occurred despite the fact that subjects were lifting a significantly lighter load.

Sometimes, using a lighter resistance can pay dividends and that was the case in this particular study. With subjects training with light dumbbells on this exercise, they were able to focus on hitting the muscle without the distractions of a heavy load to control. All this made for fresh results.

So despite the fact that this exercise has long been relegated to the “if I have time” category on arm day, it is actually a hidden gem when it comes to packing on lean size and toning your arms in double quick time. You may have to dust off some old muscle magazines to see it performed, but the latest studies confirm it'll be worth your while.

Dumbbell kickbacks are now proven to be the best triceps exercise .