The use of weighted baseballs ranks right up there with the controversy over who shot JFK. Most of the controversy is based on ignorance and opinion. These anti-weighted baseball feelings are fueled by ‘medical rationale’ and logic. What I would call a ‘rehab’ versus ‘prehab’ mentality. Many of those who oppose weighted baseball training do so based upon their common sense. Common sense which says to them throwing something heavier than a regulation baseball exposes the player to greater risk of injury because it creates greater stress on the arm and body. Which is exactly opposite as to the common sense I had 40 years ago when I believed that throwing something heavier would better prepare me to throw something lighter.
To sort out which common sense makes sense requires and understanding of training physiology i.e. how the body responds to stress. This is embodied in the first principle of training and I quote from Nueralmechanical Basis of Kinesiology, 2nd Edition, Roger M. Enoka: “Substantial effort has been focused on determining the nueral mechanical basis of muscle strength. As a result of these efforts, several rules for the prescription of exercise have been elaborated. These rules are often referred to as the principles of training. One such rule is the overload principle (DeLorme, 1946) which may be stated as follows: To increase their size or functional ability, muscle fibers must be taxed toward their present capacity to respond. This principle applies that there is a threshold point that must be exceeded before an adaptive response will occur.”
There are at least a dozen research studies on throwing/training with the use heavier and lighter of the baseballs and I quote (ASMI): Seven overweight and four underweight training studies (6 – 12 weeks in duration) were conducted to determine how throwing velocity of regulation baseballs was affected due to training with these overweight and underweight baseballs. The overweight baseballs ranged in weight between 5.25-17 oz, while the underweight baseballs were between 4-4.75 oz. Data from these training studies strongly support the practice of training with overweight and underweight baseballs to increase throwing velocity of regulation baseballs.”
It is also important to note that none of the studies report any incidence of injury. The studies involved at least 500 to 600 players primarily aged high school and older. Anecdotally there are many success stories associated with throwing objects heavier than a 5 oz. baseball. The following quote is from an article by Pat Jordan, September 14, 2003 issue of the New York Times Magazine entitled The Hardest Stuff quoting Billy Wagner: “There’s no way I should throw a baseball 100 m.p.h.,” he said. “I’m small. I see guys 6-foot-8 throwing 88. There’s nothing I did to get it. Maybe throw a football a lot. I have the short, quick arm motion of a quarterback. Some say it’s in my legs, or my wrist. But I don’t know why.”
A football weighs 15 oz., three times the weight of a regulation baseball.
“When he was little he grew his strong arm by throwing rocks at chickens.” Describing how Satchel Paige developed his arm: Satchel Paige by Lesa Cline-Ransome.
Bottom-line is that a well-designed weighted ball training program improves the ability to throw a baseball. This improved ability to throw many times translates to improving the skill of pitching.