Arm CareLatest ArticlesMobility/FlexibilityStrengthVelocity Improvement

IN-DEPTH: How & Why Weighted Balls Increase Velocity

IN-DEPTH: How & Why Weighted Balls Increase Velocity

Weighted Balls Increase Velocity, BUT NOT How/Why You Think

Most assume velocity gained from weighted ball training is a result of increased strength.  Simply anticipating the evidence is in the name itself.  However obvious this assumption my seem, it’s incorrect!

The name alone, “weighted balls”, causes us to immediately associate these objects with the word “strength”.  Because when we think of weighted implements we think strength.  Which makes sense because throughout our lives we recognize the two commonly go hand in hand.  Lift weights, get stronger!

Even when coupling either “weight” or “strength” with the word “training” we commonly do so interchangeable.  Unless your occupation is the physical training of human beings, “strength training” and “weight training” mean the same thing.  A trainer on the other hand may distinguish the two by reserving the term “weight training” for training which involves weighted implements.

Regardless, to physically train requires us to place force on our body.  Whether that force comes from a weighted implement or our own body weight.  There is always going to be some aspect of force from weight and time.  Followed by our bodies adaption to the combination of those demands to produce a result.  These physical results come in the form of strength, speed, flexibility, endurance and coordination.   Coordination being the general “skill” to complete a task, whether requiring hand-eye coordination, agility, accuracy, balance, timing, etc.

The Objective vs The Result

The same goes for weighted balls and utilizing them to train an overhand athlete.  Of course the “objective” for most is an increase in throwing velocity.  Conventional wisdom sways us to believe this “objective” is as a “result” of added strength.  After all it is a weighted implement we are using, so shouldn’t the old adage “lift weights, get stronger” apply?

Well yes and no! Yes, in some aspects you are getting stronger.  But NO, strength is NOT the primary reason you are throwing the ball FASTER now!  Knowing and understanding the reason why may not seem important, but it is. It is very important.

Which is why it is important for us to understand the difference between an “objective” and a “result”.  With any combination/recipe of actions or ingredients we almost always have an “objective” in mind.  However, we all understand if we don’t use the proper combination/recipe of actions or ingredients our “result” is not going to meet our “objective”.  For example, if your objective is chocolate ship cookies, but the recipe you followed was for brownies.  No matter how bad you wanted those chocolate ship cookies, your result is going to be brownies.  The EXACT same is true for training.  A bodybuilder and long distance runner have completely different “objectives” they are trying to achieve.  So to be successful in achieving their “objective” their training recipe, or combination of actions, MUST be specific to their desired “result”.

Why Is Why Important?

I’m sure you are thinking “you’re not telling me anything I didn’t already know, this is all common sense stuff”.  So now let me tell you WHY this is SO IMPORTANT.

The best and most successful people in any field, activity or industry are the “best” because they UNDERSTAND the HOW AND WHY BETTER!  It’s the reason two cooks can follow the same recipe and use the same ingredients.  Yet the “better” cook’s results always seem to taste better.  Because the “better cook” has a better understanding of how and why the ingredients, and their combination, interact with one another.

So now lets examine weighted ball training specifically.  Mainly how our body is forced to adapt to the demands imposed from the combination of force from weight and time.

Rather than biasly jumping to one particular primary reason.  We’ll examine each of the five perspective results of any physical training: strength, speed, flexibility, endurance and coordination.

How Weighted Ball Training Affects the Body


Let’s start with the elephant in the room, STRENGTH.

As many “studies” within the baseball industry have already claimed/alluded/stated.  THROWING weighted balls is not a sufficient means for gaining ARM STRENGTH.  However, USING weighted balls is a different story.  By performing what we refer to as “HOLDS” (or continuously holding on to the ball throughout the throwing motion, never releasing it), athletes are increasing strength in their deceleration muscles, mainly the posterior shoulder.  Contrary to what some have said, “HOLDS” do not negatively impact pitching mechanics.  Rather, this notion is simply something a company with ulterior motives made up for their own benefit.  It directly contradicts their own use of weighted balls for throwing and is opposed by the scientific rules of adaptation.  But you can read more about this in a later section, at the bottom of this article, titled “False Information Regarding “Holds””.

In regards to deceleration strength, some contend as a manner of self preservation, our mind and body will only allow us to accelerate as fast as it can decelerate.  Like a safety switch neurologically wired into our bodies to prevent it from injuring itself.  If this is true that means our decelerators are essentially a governor for our accelerators.  Whether this is true or not, when it comes to strengthening our decelerators for the function of throwing a ball overhand and forward, “holds” are likely the best method for accomplishing this objective.

Whereas other exercises like reverse throws are not only NOT FUNCTION.  But in regards to backside strengthening, they are providing concentric strengthening.  Yet when we throw a ball overhand and forward, our backside is decelerating our arm eccentrically.  Not that we shouldn’t examine options for developing concentric strengthening.  Since it does promote balance and balance has a long standing reputation of helping prevent injury.  But that’s for another day as this discussion is about why weighted ball training increases velocity.  Since reverse throws are not a sufficient manner for functionally strengthening the decelerators in the same eccentric manner our arm relies on them when throwing a baseball/softball overhand.  We can fairly confidently eliminate them as a potential way to increase velocity.

“Holds” on the other hand, strengthen our decelerators eccentrically.  In the exact same manner our arm relies on them to throw a baseball/softball.  Thus they could contribute to an increase in velocity.  Especially when you couple their functionality factor with the principles of neuromuscular adaptation and the theory of deceleration governing acceleration.  But, in regards to “strength” and even the functional strength “holds” provide.  Since there are many weighted ball training programs that do not include “holds” in there programming, we will save time and eliminate them, and thus “strength”, as the primary reason for increased velocity.

Arm Speed

Next we’ll discuss arm SPEED.  Again, a topic that has been fairly thoroughly discussed by many within the industry.  Most of which will agree, throwing overloaded balls (or balls that are heavier than a regulation 5oz baseball) shows no evidence of improving arm speed.  However, MOST will agree throwing UNDERLOADED balls (or balls that are lighter than a baseball) can improve the speed at which the arm moves.  Thus increasing arm speed.  Even though we are confident we can safely train the arm to move faster with underload throws. We do not believe it is commonly the primary reason for increased velocity.  It is also important to remember, as most can understand, the faster the arm is moving the GREATER the stress on the arm.  Which is why the quantity of underload throws is very important and should be specifically prescribed based on the individual athlete.


Now for flexibility.  This is a more controversial topic.  We could, and likely will in the future, write an entire blog article just on this particular component.  Maybe even multiple.  But spoiler alert, it’s not the primary reason for the velocity increase.  So we’ll try to keep it to more of a summary this time around.

When we discuss flexibility we’re literally referring to the range of movement in a joint.  Which enables our body to bend and rotate.  There is no disagreement throughout the industry that throwing weighted balls may effect shoulder rotation.  However, USING them for BOTH HOLDS and THROWS and the effect of internal versus external rotation, as well as to what degree, poses some controversy.  Now, whether the additional rotation is good or bad is completely unsettled.  But for this particular topic we can jump straight to some of our own data.

In the last 12 months alone we have collected over 10,000 assessments for shoulder rotation in baseball and softball players.  There is NO ENTITY with more data on this particular subject.  Because in regards to arm injuries, shoulder rotation seemingly plays a pivotal role.  When paired with usage/workload data the feedback is CLEAR!  On average athletes who throw more have less internal rotation in their throwing arm vs their non-throwing arm, PERIOD!

Overuse and imbalance are never looked at as positives.  In this particular situation these two negative attributes go hand in hand.  Prior studies of this internal rotation imbalance term this condition Glenhumoral Internal Rotation Deficit (“GIRD”).  Those studies indicate a 20 degree deficit is a likely indicator of shoulder pathology, future injury, and reduced performance.  While also hypothesizing that GIRD is a direct result of the imbalance in accelerator (external shoulder rotation) versus decelerator (internal shoulder rotation) exercise.  All of which aligns directly with the findings of our data.  Additionally, our data shows that participants who utilize our weighted ball throwing program (which includes “holding” and throwing weighted balls and is coupled with our arm-care and strength training) see an improvement in internal rotation in as little as six weeks.

Again, though we believe this is a very important element. Which we are confident proper training modalities can improve. We are not so confident these improvements, and the additional health resulting from these improvements, are the primary culprits behind velocity increases.


When it comes to endurance, as most would expect, it lies on the other end of the spectrum when we’re discussing increased velocity.  As with any well designed training program you must account for some aspect of endurance conditioning.  Depending on your particular “objective” will determine the portion and extent at which your training incorporates “endurance” activities.  In the end, yes, you can improve endurance through the use of weighted balls.  But as it relates to “why throwing weighted balls improves throwing velocity”, improving your endurance is not going to effectively improve your top-end velocity.


Out of the first four training “products”, one is irrelevant to the topic, and the other three are surrounded by some controversy.  While none of these “training products” garners industry wide acceptance as a positive attribute of weighted ball training.  We should point out that the manner in which we prescribe the use of weighted balls differentiates our position as to their effectiveness in yielding these positive “products”.  When properly utilized we are confident they can positively attribute to “strength”, “speed”, “flexibility”/rotation and “endurance”.  Though, again, endurance is largely irrelevant to this discussion of increased velocity.

But the time has come to reveal the PRIMARY reason velocity is gained through weighted ball training..  COORDINATION!  It’s the neurological and physical growth the body experiences through the advanced training imposed by various weighted implements.  Because throwing implements that vary in weight, is the most advanced and extreme, yet functional, method of training a thrower’s kinematic sequencing and timing!

Why do I say this?  Simply put kinematic sequencing is the ORDER of MOVEMENT over TIME (sequence of motion through time) to complete a task.  Transferring energy from one segment of the sequence to the next and ultimately to an end point.  Like the task of hitting a baseball or golf ball, or in this case throwing a baseball or softball.  In exercise these may be referred to as movement patterns.  The efficiency of a kinematic sequence is commonly determined by the amount of energy transferred from one segment, to the next segment in the sequence.  Under ideal circumstance this could be effectively measured by comparing the amount of energy generated, to the amount of energy transferred to the end point.

Coordination: Timing & Sequencing

But when striking a ball, like in golf and baseball, we have the inconsistent variable of hand-eye coordination necessary to actually strike the ball and transfer the energy.  Whereas throwing an object negates that variable because the energy is transferred through the release of the object.  With the release point being an element within the sequence.  Thus it’s rational to contend the efficiency of a thrower’s kinematic sequencing can be fairly accurately measured by the outcome/result.  Examining the amount of energy produced, versus the amount of energy transferred to the object being thrown/released.  So when it comes to throwing an object, most can agree, the variable with the most significant impact on the outcome/result is TIME.  The TIMING of the order of movements, the point in TIME the ball is released and of course the speed at which this is all done (speed being distance traveled over TIME).

So when we train using a variety of weighted implements our kinematic sequencing must adapt to the to the speed at which our arm is moving.  The heavier the implement the slower our arm moves.  The lighter the implement the faster our arm moves.  In any consistent sequence each segment must adjust accordingly to the remain ordered.  So when training our kinematic sequencing with implements varying in weight we are forcing it to adapt to the speed of the arm.  In essence increasing the “challenge” of the activity/demand and the stimulation it provides.  Especially as it relates to the TIMING of our sequencing.  Thus breaking up monotony and stimulating the nervous system while promoting advanced biomechanical and neurmuscular development.  Which is why I contend weighted ball training is “the most advanced and extreme, yet functional, method of training a thrower’s kinematic sequencing and timing”.

Supporting Our Theory

This contention is supported by a plethora of physiological principles and concepts.  One such concept is the SAID principle.  Which by many is considered “one of the most important basic concepts in sport science”.  It suggests that the body adapts specifically to imposed demands.  Stating “given stressors on the human system, whether biomechanical or neurological, there will be a Specific Adaptation to Imposed Demands (SAID).”

It has long been recognized the body is designed to adapt (ex. neuron adaptation followed my physical adaptation in response to resistance training).  So too has the bodies tendency to plateau as a result of monotony.  As is evident in the Overload Principle.  This basic sports fitness training concept asserts “in order to improve, athletes must continually work harder as they their bodies adapt to existing workouts/loads”.

Monotony is also the primary subject of the theory of “neuro stagnation”.  Which suggests when constantly performing the same task with the same load and strain the lack of neurological stimulation leads to a decrease in neuromuscular development.  Well supported research also indicates “monotonous program over training suggest that repetition of the same movement under the same load, such as certain weight lifting and baseball batting, can cause performance plateau due to an adaption of the central nervous system which results from a lack of stimulation”.

Concepts Into Practice

Notice, each of these well established principles and concepts has one very important variable in common; stress and load from WEIGHT.  It’s important to understand that ACTUAL WEIGHT is not the only aspect they are referencing when they refer to stress and load. As they are referring to both “external” aspects.  Which applies to all sport and non-sport specific “work” (this includes weight, reps, distance, etc). As well as “internal” aspects.  Which refers to physiological and psychological response to external loads, combined with daily life stressors and other environmental and biological factors.

But regardless, ACTUAL WEIGHT is a significant variable that plays a significant role in each principle/concept.  Which aligns with our contention that the variation in ACTUAL WEIGHT in weighted ball training provides a greater demand with greater stimulation.  The greater the stimulation of a demand, as long as it is rational, the greater the adaptive response will be.  So when our body faces a demand that is stimulative and rationally greater than it is accustomed to and enough recovery time is given to the trained physiological system, the body will adapt to the stressor. Becoming more efficient and effective in handling said stressor.

Avoiding Monotony

Which is why in conventional strength training when performing an exercise that includes the use of a weighted implement, the athlete will adjust the weight used over time.  I have often heard trainers refer to this as “muscle confusion” or an effort to “excite the muscles” or “keep the muscles guessing”.  That may sound silly, but it is exactly what they are doing.  Adding variation to the exercise to increase stimulation, in an effort to overcome monotony and improve the results of the workout.  Which is a fairly proven method for increasing neuromuscular adaptation in training.

So, shouldn’t it make sense that by adding variation to the weight of the balls we are throwing, we can elicit these same increases in neuromuscular adaptation as a result of the increased stimulation of the demand.  After all, when it comes to the human body, whether mental, physical or neurological, stimulation commonly leads to development, which ultimately results in increased performance.

Additional “Coordination” Benefits

Other improvements in “coordination” as a result of weighted ball training include; improved movement pattern awareness, as a result of the variation of weights enhancing “feel” or physical feedback. Throwing weighted implements can also improve arm path/action by assisting an athlete in finding their ideal “point of strength” as they guard against vulnerable positions. The added challenge of training with various weighted implements can also improve concentration. Enhanced concentration has proven to be very beneficial in any training that requires skill and neuromuscular coordination.

At the end of the day challenging ourselves mentally and physically leads to growth. Finding ways to safely and effectively implement new challenges can help enhance and harness new growth. Properly programming and implementing a weighted ball training program is a great example of this.  But keep in mind preparation, technique, balance and RECOVERY are all very important elements in any well configured training program.

The Take Away

This in depth look at “how weighted ball training improves velocity” can and should be useful in helping determine their value in your training plan.  A few important points I hope you were able to take away are:

  • First, improved “coordination” (or kinematic sequencing/timing) is a product of the functionality factor of weighted ball training.  Thus a steadfast commitment to performing this training “functionally and mechanically sound” should remain a priority.
  • Second, the variation in weight of the balls being thrown provides advanced training of sequencing and timing.  So contrary to what some have said, focusing on location during training, without significantly altering intensity, is extremely beneficial.  This focus on location within training was a primary method we used to support our theory that “coordination” is the primary reason weighted ball training improves velocity. Because, fundamentally, coordination is where movement/action meets TIME in space.
  • Third, and finally, though we contend “coordination” is the primary “training product” responsible for improved velocity.  It’s the combination of these positive “training products” that contribute to safe, health, sustainable velocity gained through PROPERLY prescribed weighted ball training.

Final Thoughts

Lastly, we pride ourselves in being an industry leader in experience with regards to weighted ball and baseball/softball (diamond) strength training and development.  But there is no one person or entity in this world that has all the answers.  Each of the physiological principles, concepts and theories referenced in this article were developed by some of the greatest minds in their respective fields.  Yet many, many question still remain around and within these well supported beliefs and ideals (which is why scientist refer to many of them as phenomenons).

Our purpose for writing this article, and those like it, is to share our experience and knowledge with individuals looking to broaden their knowledge and advance the game.  However, please do not confuse that intent, or our company’s efforts, with those out there arrogantly pretending to “know it all” and have an “answer” and “solution” for every problem. Don’t get me wrong, we work as hard or harder and have as much or more experience than anyone in our field. In fact we were the first group to use “plyo” balls in a throwing program.

When we started using them back in 2009 no one made them for diamond sports, so we had to use much larger Pilates “toner balls”.  Many people also don’t realize, it was a guy performing our training program, in our facility, that led to a segment on HBO’s documentary series “Real Sports with Bryant Gumbel” that aired back in March of 2012.  That HBO segment is what gave life to ALL of the popular weighted ball programs being used today.  The point is we’ve been doing this at a high level for a long time. Yet we continue to challenge ourselves to learn more and improve ourselves and our product each day.

Additional Reading

Summary of how we developed this conclusion:

What led to this conclusion?  It was a culmination of various research we’ve performed over the years.  None of which was focused on determining why velocity is gained through using weighted balls.  This was not the singular or primary objective of our research efforts.  But rather a product of inquisitive research subjects and noticeable outliers that quickly resulted in this conclusion.

Research: Tracking

So going back to 2012, 2013 and 2014 when we were performing a lot of research.  Primarily in an effort to better revise and quantify our programming algorithms.  A large portion of this research involved collecting our own set of in-depth data analysis on a group of athletes that we work with locally in our facility.  This was important for establishing constants.  Because even though we received tens of thousands of remotely submitted test results each year.  The results were not being collected under our supervision, which could leave questions open to their validity and consistency.  Plus we wanted more metrics, depth and detail, which we could only confidently gather ourselves.

So within our process we tracked EVERY rep and throw from EVERY workout these athletes completed.  One such variable we began tracking from day one was ball velocity.  In order to ensure the utmost accuracy we would use two radar guns simultaneously to collect and record every throw, for every ball, from each position.  In addition we used a device to collect arm speed (this was prior to the Motus sleeve existing).  Once the Motus sleeve was released we added it and its metrics to our arsenal.

Research: Outliers

One particular variable that each participant wanted to review after each workout was throwing velocities.  When examining these velocities it would almost never fail that the participant would notice a higher/faster outlying ball velocity amongst a group of throws (usually 3-4mph greater than the other throws made with the same weight ball, from the same position).  Followed by the inquiry “why did I throw the ball so much harder on this throw”.  First, if the outlier was consistent between the two radar guns, we would confirm the outlier was “good data”.  It’s important to understand many outliers are the product of inaccurate radar equipment (i.e. “bad data”).  It’s for this reason we used the same two professional grade radar guns to record every throw from within the same area and in the same facility over the full life of this research.  This was done to insure proper constants were maintained.

Ball Velocity and Arm Speed

So anytime we were asked about one of these higher/faster outliers.  After confirming it was accurate/good data.  The next thing we would do is examine the order in the group the outlier came.  If the outlier was not the first throw (which could indicate it was only faster because the slower throws that followed were performed in fatigue) or the last throw (which may indicate the participant was “warming-up” or adjusting to the weight with the preceding throws).  But instead occurred in the middle of the set, the only logical reason we could discern for this outlier was more efficient kinematic sequencing/timing on the particular throw in question.

We then began to cross reference these throwing velocity outliers with the coinciding arm-speed data and discovered the two were far from linear.  Which supported our theory.  Because had the relationship been linear and each higher velocity outlier been a direct result of arm speed being higher.  We could have and likely would have contributed it to a result of intensity.  However, well over half of the outlying instances indicated the arm speed was less than or equal to the arm speeds of lower surrounding throwing velocities.  Meaning the arm was moving at the same speed or slower, but the ball was traveling faster.  So either the time/point of release, or some other segment of kinematic sequencing/timing was more efficient/optimal for that particular outlying throw.

Research: Conclusion & Further Support

We were also able to draw many other relationships.  Including that of age, experience with the training over time and many more correlations in our data.  Inevitable, as outlined in this article, we rather confidentially concluded this training method dramatically improves kinematic sequencing and timing.  We also understood the greatest way to harness and transfer these velocity gains to consistent, useful, on-field performance is through a 5oz regulation baseball directed at a point of intent.  Otherwise we are not maximizing one of the most significant “products” of this training method, improved coordination/skill (release point, timing and sequencing).

So in order to maximize the training of release point, timing and sequencing (i.e. coordination/skill), we incorporated a “target” into all of the training we prescribed.  First to our local test/research group and then, two years later, to our mass customer base.  Since implementing this adjustment to our entire customer base almost three years ago, our participants average velocity increase is up 23.7% from prior years.  In addition we have received comment after comment from customers thanking us for improved command.  This adjustment also further confirmed how significantly weighted ball training can benefit “coordination” (timing and sequencing) and in-turn the significance at which “coordination” impacts adding velocity.

False Information Regarding “HOLDS”

One note I thought was important to add in this article was the false information surrounding “holds”.  Specifically for those that believe “holds” in training negatively (or generally) impact pitching mechanics.  Those that say/think/believe this, are not only contradicting themselves if they endorse weighted ball throws.  But they also don’t understand many well supported physiological principals of adaptation.  Namely those of SPECIFIC adaptation to imposed demands.  In regards to contradiction, any video analysis of a varying weighted ball throws will quickly uncover mechanical and arm path/action adjustments the thrower’s body naturally makes to adapt to the weight of the implement.  So to say the adaptation a thrower’s body makes to continue holding onto a ball, is bad; but the adaptation the body makes to the weight of an implement when throwing it, is ok, is completely contradictory.

In addition to being contradictory, it is also ignorant and unsupported by physiological science.  Because as scientist have long acknowledged, our bodies are designed to specifically adapt to the imposed demands.  Whether that adaptation is a result of the “demand imposed” by the weight of the ball or the lack of releasing the implement.  It is designed to adapt specifically.  Meaning when you switch back to the 5oz ball and begin “throwing” it, it will once again adapt accordingly/specifically to that demand.

When, Where and Why This Fact-less Notion Exists

If you look back to when and where this idea started you’ll notice it came from a company that at the time was new, small, unknown and inexperienced.  A company that was just starting up and trying to gain traction.  In what would seem an attempt to point out FALSE fault in a larger more experienced groups methods, that at the time were gaining a LOT of attention.  So rather than a profound and legitimate discovery.  It would appear to be more of an underhanded way for a smaller, less adequate, company to gain traction.  By throwing mud and stealing attention from their more popular, superior competitor.

When you’re smaller and less popular than your competitor, it’s tough to compete in selling the exact same product.  You need to separate and differentiate yourself.  Which in this instance came through altering their product JUST TO BE DIFFERENT.  Followed by false claims to why this alteration was necessary and how it makes their altered product “better”.

We refer to this business approach as “taking the low road”.  That larger, MUCH more experienced group getting all of the attention, that was our group.  Because of that attention and notoriety, we were taken aim at by the little inexperience start-up looking to gain traction.  We founded the Velocity Plus Arm Care program.  The first of it’s kind.  It paved the way for virtually all of the popular weighted ball programs being used today.  We may no longer be the larger company.  We definitely don’t sell as much equipment.  But we are still more experienced and our approach still remains the same; provide a superior product.  By putting it into an app a couple years ago, we once again paved the way.  Now our product is more affordable and convenient.  Accessible anytime, anywhere to anyone.

Feel free to learn more about our Throw Smart mobile app or read more of our blog articles.


Next article Technology & Performance: Real-Time Data for Real Life Gains
Previous article Isometrics Training - When Push Comes to Shove

Related posts


    • If performed functionally long toss can be a great tool. It’s when athletes get outside of quality, efficient and functional mechanics, in an effort to throw the ball as high and far as they can, that we believe long toss becomes an ineffective training tool.


Leave a Comment

Your data will be safe! Your e-mail address will not be published. Also other data will not be shared with third person. Required fields marked as *