Weighted ball training is a hot topic of debate in the baseball world.  The manufacturers, many pitching coaches, performance coaches, and players all swear by them, claiming it’s a proven way to increase velocity.  Detractors pose that there is an increase injury risk associated with throwing weighted balls.  So, what are we to think?  In this article I’m going to sum up the theory and pros & cons of throwing weighted balls as well as offer my own opinion.

Weighted Baseball Training: The Theory

Before we take even one step forward, I want everyone to understand one extremely important fact about the weight of a regulation baseball: ITS ARBITRARY.

People get so caught up on believing that throwing a regulation 5oz baseball is the safest, no matter what.  Many say that throwing a weighted ball (heavier than regulation) is going to hurt your arm.  But guess what? Doctors didn’t choose the weight of a regulation baseball back in the 1880s based on it’s impact on the human body, and I think people forget this.  Rather, our bodies just adapt to throwing the 50z ball, because it’s “normal” to our throwing arms.  Anything higher or lower than this normal ball just means stressing the arm in a different, but not necessarily injurious, way.  If baseballs were traditionally 9 ounces, our arms would consider that normal as well.  So, don’t consider a weighted ball evil just because it’s different than what is traditional.  After all, javelin throwers throw a javelin weighing several pounds and don’t suffer more injuries than baseball pitchers.  That said, lets get going…

The Basics

Weighted balls are made anywhere from 6-12 ounces in traditional baseball form, and go even heavier as sand filled mini-medicine balls.  Ron Wolforth, at his Texas Baseball Ranch, uses some of the sand filled balls for drills with his pitchers.

Yet, the protocol for building velocity that is now held as the gold standard appears to be the overweight-underweight throwing program.  This involved throwing a 6oz ball, a regulation 5oz ball, and an underweight 4oz ball in a 2:1 ratio of underweight/overweight to regulation.  This means if you threw 60 pitches in the program one day, you would throw 20 heavy, 20 regulation, and 20 underweight.

Why overweight and underweight? It builds on the theory that your muscles need both strength and speed stimuli to learn to consistently move an object faster.  Throwing the 6oz ball makes the arm move slower (after all, it weighs 20% more), but with more force.  The underweight ball allows the arm to move faster but with less force.  So, combine the two, and your arm gets a combination of strength and speed stimuli.

This overweight/underweight program has shown to be successful in sprinters using hills.  Flat ground is regulation, and uphill and downhill are the novel stimuli.  By making a sprinter go uphill at top speed, he must apply more force to the ground to get where he is going.  He can’t move as fast, but builds strength in the process.  Send that same sprinter at top speed downhill, and his legs are forced to turn over much faster than normal, thus helping increase his stride frequency. Sounds reasonable right?

It is.  A 20% change in stimulus has been said not to be overly stressful on the body, and is optimal for performance.  Who says this and where did they get their data? I’m not sure, so let’s not become convinced just yet…

Are Weighted Balls More Dangerous?

Unfortunately, I don’t have an answer to this question.  However, lets go back and think about what we have already discussed on the matter:

1. The traditional 5oz baseball is a bodily stimulus that was chosen for our arms arbitrarily.  Javelins weigh several pounds, and aren’t shown to be more injurious.
2. The body adapts to stress.  Bones become more dense from weight training, and connective tissue becomes thicker and more resilient.  There is no reason to think this phenomenon is not present in baseball throwing.
3. A weighted ball cannot be thrown as hard, so stresses on body tissue MAY not be greater than that of a regulation or underweight ball.  Stress on the arm is a product of weight and arm speed, so a heavier object moving slower MIGHT NOT produce increased force.  Do I have data on this? No, but it’s simple physics.
4. There are no studies out there proving that weighted balls are more dangerous.  It’s unfortunately incredibly hard to nail down exactly the variables at work when dealing with the human body.  If a player tears a ligament throwing a weighted ball, how can we validly infer that it was the weighted ball, and not his poor mechanics COMBINED with the weighted ball that caused it. Or maybe his ligament was already deteriorated to the point where ANY throwing was going to cause the final tear.  It’s difficult to know.

What Can They Do For Me (And What Can’t They)?

They can stimulate your throwing muscles in a new way, there is no doubt about that.  If you squat 100 pounds every day, then suddenly throw 200 pounds on the bar, your body WILL feel a new stimulus and adapt – It’s just the way we work.

Most notably, weighted balls will stimulate the concentric phase of throwing, which is the acceleration phase.  Yet, because the arm is moving slower with a weighted ball, the decelerators will not have to work as hard, and as such will be faced with LESS of a stimulus than a regular ball thrown with more velocity.

What’s the problem with this? Your body needs to have equal strength to both accelerate and decelerate the arm, or any body part for that matter.  Your body will not let you throw your arm out the socket, which is more or less what would happen if it allowed you to throw a ball 90mph without the strength to slow a 90mph down to zero.

This is, however, where the underweight ball tends to shine; because your arm is moving faster than it otherwise would, it has to learn to slow a faster moving arm down in the same amount of time. Yet, I would hypothesize that this action, throwing a lighter ball faster, would be potentially more injurious than a weighted ball, simply because your arm might not know how to deal with the increased speed.  Is there research behind this? Again, no. Strengthening the rotator cuff in a ballistic manner to accompany weighted ball training would be ideal, and maybe allow for more gains from it.

And on the subject of gains…any gains made will take time, and will vary depending on the thrower.  Untrained athletes make the biggest gains in the least time, and highly trained athletes fight for just a few percentage points of increased performance.  This is called (drumroll, please) diminishing returns.  Rest assured, that ANY type of training, weighted ball included, takes time to work.  Expect any gains to take at least 4-8 weeks, if your body makes gains from them at all.  You wouldn’t expect to squat 400 pounds overnight, so don’t expect a magic bullet with this type of training either.

To summarize what overweighted balls can and can’t do for you, based on their fundamental principles:

• CAN provide a strengthening stimulus to the arm in the concentric phase of throwing
• CANNOT provide strengthening in the eccentric (decelerating) phase of throwing
• CAN increase load and stress on soft tissues IF (a big if!) thrown with enough velocity to surpass the total load provided by a regulation baseball
• CAN potentially make your arm more powerful, but slower moving, if not coupled with higher velocity, such as underweight, training.
• CANNOT increase permanent velocity increases overnight

So, hopefully we have now have a decent understanding of what weighted balls can and cannot do for you.  Weighted balls, in theory, have some good application, but also have limitations, mostly in their lack of ability to increase decelerating strength.  Their role in arm injury is anecdotal at best, so it is best to do your homework and use them under proper supervision, if you feel they are appropriate for you.  Individual results vary according to the protocols used, but I know that some swear by them and others swear at them, making it again, a personal choice that should be based on some solid research.

To Throw or Not to Throw? Good Question. Feel free to comment with your thoughts…

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