So far, research suggests that there are a few exercises that access the brachii muscle activity on your triceps. The results from this research can be summarized in these six points:
#1. Multi-Joint and Single-Joint Exercises Have About the Same Effect.
This may come as a surprise but when researchers Bohler and Soares compared the EMG (muscle electrical activity) on your triceps between single-joint and multi-joint exercises, they found that it’s quite similar. This is only the case when you’re doing the traditional bench press, close-grip press, dips, triceps extensions (lying, overhead and pushdowns), but only at a weight around your 10-rep max.
#2. The Exercise Ball Is Useless
Saeterbakken did some research in 2013 on the usefulness of exercise balls, and the results were unexpected. They said that when you do pressing exercises on a Swiss/exercise ball, you get worse results than if you were to do them on a stable, rigid surface. If you want to use the triceps as much as possible, get a stable position and a stable load, meaning a barbell and a bench.
#3. Barbells Are Better Than Dumbbells
The barbell and dumbbell exercises usually produce very similar results, but not when it comes to the triceps. Doing your overhead press on a Smith machine or just a normal bench will produce better results than doing any dumbbell bench or overhead press. Saeterbakken did two studies on this in 2011 and 2013 and discovered than when using dumbbells, you limit yourself in the amount of load lifted.
#4. Go Heavy
Your triceps knows when you’re lifting light weights, so trying to fool it is useless. Muscle activity increases as you increase your weight, but when you do a bench press with the strongest intent and acceleration, all the heavier loads, such as those close to your one-rep max, will involve your triceps better than any lighter loads. This was discovered by Newton et al. in 1997.
#5. A Slight Decline or a Flat Bench Works Best
If you want to do multi-joint exercises, you want to do the barbell bench press. Find a flat bench or one with a slight decline and pump away. Barnett discovered this in 1995, adding that your triceps was activated better at a decline or on a flat bench as opposed to an inclined bench.
#6. Keep Your Grip Narrow
Lehman discovered in 2005 that using a narrow grip doubled the EMG amplitude of your triceps as opposed to using a wider grip. So, keep your grip narrow when doing that bench press!
So, with all that in mind, how do you train your triceps? Well, it appears that when you do heavy bench presses, you get the best EMG amplitudes necessary for improvement, but you should also note to take care of your anatomy and individual moment arms at the head of the triceps, which is the length between your joint axis and the vector of force acting on it. The bench press can be improved further to produce even better triceps results if you use a narrow grip as opposed to a wide one. So, close-grip bench press it is! You might even want to do this exercise in a way that will bring most of the intensity on the top part of the lift. For example, you may want to do some partials, such as board presses or floor presses, but you can also use other tools, such as training bands or chains to switch up the resistance in the exercise as you see fit. Remember, variations will do the impossible in the long run!