There are a plethora of triceps isolation exercises and each one hits all three heads with a distribution of emphasis depending on the exercises. For example, overhead tricep extensions will work the long head more than push-ups because the long head is more lengthened during each rep of the exercise. With that said, there are plenty of EMG data indicating that the long head of the triceps will have muscular activity during any triceps exercise. I’ll just share a link to the first website that I found that has a table of the EMG activity for the long and lateral head of each exercise on page 2 with the highest being triangle pushups. From experience, I remember doing these in high school and really felt the triceps. However, to incrementally load them would be tedious. A viable way to progress in that exercise is to incrementally add a plate by (1.25 or 2.5lbs) each session or two and maybe up until 5-10 lb then add a rep. I digress. For the longest time, I’ve heard mixed opinions of wether doing long head tricep exercise was necessary instead of doing just doing compound or typical lateral head triceps exercise like tricep pressdowns. For the past three months, I’ve seen how doing triceps pushdowns with its variants positively affects dumbbell lying skullcrushers twice.
Instance #1
Each day I would do dumbbell skullcrushers, it would be at least a few exercises after doing bench press(or partial bench press) or tricep pushdowns. The one day (on 5/28/24) that I chose tricep pushdowns as my first exercise instead of bench press, my skullcrushers didn’t progress and stayed the same as (5/25/24) when I did dumbbell skullcrushers (40lbs x 16 reps) on the usual bench press day. The next day I did skullcrushers with bench press ( 5/31/24), I did 18 reps with the same weight of 40lbs in the skullscrushers. This indicates to me two things: 1) the bench press didn’t fatigue the triceps enough compared to the triceps pressdown due to my weak point of the bench press being the front delts. 2) the triceps pressdown did however work the long head enough to encourage encourage it to grow due to it being an isolation exercise where I gave the muscle nearly maximum effort.
Somewhere in late June, I felt the need to replace the dumbbell skullcrushers and decided to pick single arm tricep pushdowns; one reason due to the previously mentioned experience.
Instance #2
My last day of doing dumbbell skullcrushers was on (6/21/24) with it being 45lbs x 18 reps @ 71.4 1RM. Before I started going single arm tricep extensions, there was one workout day (6/28/24) where I did Close Grip Bench Press at 165lb x 10 reps @ 220 1RM. My first day of single arm tricep extensions was on (7/1/24) with the weakest/left side being 30 lbs x 20 reps @ 50 1RM. Within these past 1-2 weeks, I’ve felt a “burnout” with single arm tricep extensions as I’ve done this exercise for at least 6 weeks. My data for (8/16/24 and 8/21/24) for SA tricep extensions was 50lbs x 11 reps @ 68.5lbs and 40lbs x about 10-15; failling at doing 22 reps. On 8/23/24, two days later, I tested the dumbbell skullcrushers at the same weight at 45 lb and I only barely manage to add in a rep. The delta (the number change) of dumbbell lying skullcrushers from (6/21/24) to (8/23/24) was 3.36% [ (73.8-71.4 = 2.4) / 71.4]. The delta of single arm tricep pushdowns from (7/1/24) to (8/16/24) was 37% [ (68.5 – 50 = 18.5) / 50].
Instance #2 Analysis
The skullcrushers might have performed better if I would gave an extra day before trying it or if I wasn’t already past an arbitrary 6 week mark of doing single arm tricep extensions. In other words, it might have been possible to add in a rep where there could have been a 7% change. Now for single arm tricep extensions, naturally there would be a rapid strength increase due to it being the first time I’ve ever done this exercise; moreso an neurological strength adaptation instead of musclar growth and strength. Perhaps, if I had already done these in the past, it could have been 15-25% increase. Regardless, this exercise didn’t seem to affect the long head of the triceps too much and my arm size seemed the same. The only other possible reason is that I naturally feel the long head more when doing regular tricep pressdown compared to single arm tricep extensions where I feel the lateral head more. Biomechanically speaking, regular tricep presswdowns has my forearm parallel to each other while with single arm work, I aim naturally aim at least slightly away from the center. Anecdotally, I felt like my lateral tricep head got bigger while my long head felt the same.
Closing
There was mixed degrees of positive results in how lateral head emphasized exercises affect the long head emphasized exercise. At this point, the think the factors that are worth considering are the shoulder rotation and wrist placement when doing each rep of tricep pushdowns as well as the neurological status of the selected exercise. For the time being, I’ll be doing dumbbell skullcrushers for a while and then go back to doing single arm tricep pressdowns for more reliable results due to less variability.
Sources
ACE Study Reveals Best Triceps Exercises, American Council of Exercise, 2012.