As far as I can tell, there are 3 main reasons why the push press is a superior exercise. I reference things explained to me by Ian Wilson and Glenn Pendlay in this short blog.
The push press is a far similar movement to the jerk than a strict press is. Specificity is one of the key pillars of any successful program. The more distant the exercise from the one you compete in, the less transfer you will get from it. This is the reason we front squat and don’t low bar back squat. It is the reason we do snatch grip deadlifts and not sumo deadlifts. When I spoke with Ian Wilson a few months ago he explained that the exercise that will transfer over the most to a snatch is a snatch. Next is a power snatch, then a block snatch, but by the time you are performing hang power snatch deficit triples you are so far from the original exercise that you are less likely to make any significant improvement. Now whilst I am not as much of a purist as Ian Wilson, I agree with his overall point. Weightlifting training must be specific to weightlifting. Of course there are times where the strict press, and maybe possibly even the low bar (in the case of a particular injury), might have some benefit to the general development of the athlete.
The movement of the push press, at least for the majority of its movement, mimics the precise timings and geometry of the jerk. The sequencing of neural firing is the same. The push press teaches you to dip and drive better, to time the press more finely, and to move more explosively. You should be unable to tell the difference between a jerk and a push press up until after the bar has left the shoulders, at which point the push press begins to develop another necessary quality of the jerk, leading me nicely on to reason 2.
2) More specificity
This was explained to me by Glenn Pendlay, and quite frankly I felt idiotic to have not thought of it sooner myself. It seems so obvious. When jerking, other than incorrect geometry of the lower body in the split as well as poor barbel trajectory, we tend to miss jerks from a lack of strength in the final lockout portion of the jerk. When we push press, we tend to miss push presses in the same final portion of the lift also. No one is unable to get a push press to their forehead height, it is when the bar is above their head that they have troubles. The push press therefore strengthens that portion of the lift well.
On the other hand…
The strict press is never missed once the bar is near lockout. The final bit of extension in the arms is easy. That portion of the movement, the most important portion, is simply not trained with the strict press. In fact the range of motion that the strict press trains most is the point where the upper arm is parallel with the floor (i.e the portion with the greatest moment arm), usually with the bar around the top of the head. This is not a part of the jerk that needs to be trained. We fly through this portion of the jerk with our leg drive. Essentially other than the benefit of hypertrophy work, the strict press trains a quality weightlifters don’t need.
3) Strength Development, and yet more Specificity…
Two of the most important muscles in the upper body to develop are the shoulders and triceps. Though the triceps are usually only needed to maintain a lockout and are normally trained isometrically, training them through some range of motion is a good idea to develop size. This remains true with the shoulders. I understand that the strict press trains them through a full range of motion, but not with the load that can be experienced from push pressing. Strict pressing anything over 60% of your jerk is not easy, but most of us can push press 80-85%. This overloads our shoulders and triceps at the exact point in the jerk where we need them to extend quickly. We need them to be strong enough to avoid press-outs. Afew reps of a 60kg strict press may help me build some much needed size far out from a meet, but it is so light it is unlikely to help me lock out a 150kg jerk. 120kg push presses, whilst developing strength and size, are more likely to transfer to helping me PR my jerk.