I’m very proud to say that our first research project on the effect of baseball pitchers training with weighted balls has finally been published! Big thanks for my coauthors Lenny Macrina, Dr. Glenn Fleisig, Kyle Aune, and Dr. James Andrews.
By now, many people have seen the results of the study. I’ve presented the data at APTA, ASMI, PBATS, Sabermetrics Seminar, and many more as we went through the publication process. We felt this study was very important for the game of baseball as we have seen such a large growth of interest in weighted ball programs, without a complete understand of what happens to the body.
I believe we have found the mechanism behind why throwing weighted balls enhances velocity. It’s not a change in biomechanics, arm speed, or strength. It’s a gain in layback. This likely also explains why these programs are more stressful and show higher injury rates. I’ve written a summary in this article, but I urge you to read the full study for all the details.