Grunt = Velo - Grunting added 2.7 mph velocity for college pitchers

Grunting added 2.7 mph compared to non-grunting for D3 college pitchers!

There’s also some research on grunting for improving tennis serve speed.

If it works for throwing and serving, why not hitting?? 

Summary:

The document is a research article titled "The effect of grunting on overhead throwing velocity in collegiate baseball pitchers" published in the International Journal of Sports Science & Coaching. The purpose of the study was to determine the effect of grunting on overhead throwing velocity in collegiate baseball pitchers. Twenty-four division III collegiate baseball pitchers participated in the study and were asked to replicate the technique of grunting during their throws. Throwing velocities were measured with a radar gun. The results showed that throwing velocity was significantly higher during the grunting trials than the non-grunting trials. Age, height, weight, and handedness had no impact on the effect of grunting on throwing velocity. The authors suggest that grunting offers a simple and immediate means of enhancing throwing velocity in collegiate baseball pitchers, and more research is needed to determine the effects in populations of different skill levels.

Link to article

Tammany, J. E., O’Connell, D. G., Latham, S. E., Rogers, J. A., & Sugar, T. S. (2021). The effect of grunting on overhead throwing velocity in collegiate baseball pitchers. International Journal of Sports Science & Coaching, 16(5), 1111-1116.