Post-Activation Potentiation with Weighted Baseballs – Chad Longworth Velo Shop

Post-Activation Potentiation with Weighted Baseballs

Post-Activation Potentiation (PAP) is a controversial topic in exercise science, with research pointing in favor and against it working. PAP is not easy to describe, but the simplest way to put it is to think about testing your 60-yd dash time shortly after squatting 3-5 reps of heavy weight. The idea is that by “potentiating” the central nervous system (CNS) using heavy movements, performance increases in subsequent lighter and explosive movements.

Does it Work in Baseball?

First and foremost, it’s important to note that the most popular method of PAP in baseball does NOT work – using a donut or weighted bat sleeve in the on-deck circle before going up to hit.

Baseball - Donut

Dr. Coop DeRenne, a legend in the world of baseball performance science, studied this very phenomenon years ago. Donuts used prior to swinging a real bat show a marked decrease in bat speed, yet hitters use them all the time. The reason for this isn’t because athletes are smarter or more experienced than sports scientists running controlled experiments, of course, it’s just a mix of inertia, superstition, and fear.

Or you could ask the scholarly people in the comments of major news sites, who have stunning results to share with us all:

Average Internet Commenter

Thanks, Doctor.

The reason that PAP doesn’t work in the on-deck circle is because the use of the donut in an attempt to increase the bat weight makes no effort to grasp the significantly changed biomechanics of the swing by adding 200% or more of the weight to the bat in an uneven distribution. This makes the loaded donut swing a completely different motor pattern by drastically changing not only the mass of the bat, but the moment of inertia (MOI) of the bat as well.

In short, it doesn’t work. So if you use donuts in the on-deck circle (or at all, really), you should stop.

But What About Weighted Baseballs Prior to Pitching?

Ah, this is the million dollar question, isn’t it? What about throwing weighted baseballs prior to pitching to potentiate the CNS to increase output?

I think this is a rather fascinating concept, and as it so happens, we’ve studied this effect as best we can in the Driveline Sports Science lab. There are three generally-accepted methods of how PAP works, and the primary one we focused on was the idea that increased recruitment of higher order motor units would activate other motor units to allow for greater than average neuromuscular performance.


Have athletes test run-and-gun velocities with a standard (5 oz) ball after a dynamic warm-up, then throw 6 oz and 7 oz overload balls for 3-5 reps each. After that, test run-and-gun velocities with the standard (5 oz) ball again and see if there are significant changes.

We also tested the OPPOSITE effect – we had athletes throw underload baseballs instead of overload to see if activation might work in a different manner.


We split the athletes into two even groups as randomly as possible while controlling for age and skill level.

First we’ll discuss the underload group: It was a disaster. Subjectively the athletes overwhelmingly hated it when feedback was solicited, and objectively the data was clear as day – velocities went directly into the tank by 2+ standard deviations.

Some things said:

  • “It feels like I’m throwing a brick”
  • “I feel like I’m going to blow my elbow out”
  • “I don’t want to throw 5 oz balls as hard as possible after that”

Pretty clear loser there. We moved underload balls back to where they’ve always been – at the end of the velocity run-and-gun tests.

The overload group, on the other hand, had mixed but statistically insignificant results. No athletes complained about the grouping of the weighted ball throws (5-6-7-5-4-3 oz) and while the average of the group saw higher velocities, it wasn’t statistically significant – and some lost velocity after throwing the overload baseballs. Some statistically insignificant trends that seemed worthy of future study were found, however:

  • Professional pitchers are more likely to see the benefit of PAP with overload instruments
  • Pitchers with certain types of arm action flaws were predisposed to realizing better velocities post-potentiation (and kinematics of the throw did change significantly)
  • Amateur athletes who had trained under the Driveline system for some time saw little to no effect

So, What’s it All Mean?

Overall, I think the idea of PAP is very interesting and perhaps useful when it comes to weighted baseballs, but perhaps not prior to a game. Our study was a very limited trial that did not test one of the most important variables in a game – endurance.

It’s very possible that a comprehensive dynamic warm-up using proper tools captures enough of the “PAP” benefits, and athletes who do not warm-up and potentiate the CNS correctly prior to training or competing may see phantom benefits from what they think is truly PAP.

PlyoCare Balls

In that vein, however, we recommend all athletes use PlyoCare balls to warm-up alongside their dynamic warm-up that should feature resistance bands, foam rollers, and other techniques to properly prepare the body and mind for competing on the diamond.

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