What I Think I Know About Weighted Balls

In this week's post Demetre Kokoris dives into the practical applications of the use of weighted balls. What is the proper way to implement this type of training, what are the main benefits, and where can you go to find out more information? All that and more covered right here!

"We read over the pitcher scouting report for the weekend, and we thought all the velocities were juiced," said a former PAC-10 hitter, "then you guys showed up, and we realized it was no joke. Everyone was 90-94, and your closer was 95-97. We'd never seen anything like it. Unreal." The 2011 University of Oregon pitching staff went on to have thirteen pitchers drafted, with four of those arms pitching in the MLB. This staff was my introduction to weighted balls, one of many factors I believe led to their developmental success.

In 2011, 88-91-mph was plenty firm. So to have an entire staff sitting 90-92, touching 94 was unheard of. My first thought was "they must of all showed up this way", but the majority of them showed up on campus sitting 86-88, with one arm coming in at 88-90. And most importantly, we lost ZERO pitchers that year to injury.

The trend was moving away from rigid consistency on the mound, and towards athletic explosiveness in training. Long distance running was being replaced by sprints, "balance points" were being replaced with "riding the slide", 120 ft catch play was being replaced by Long Toss (over the length of a football field when possible), and instead of icing after an outing, you could find the pitchers in the bullpen using weighted balls, for both velocity development and active recovery.

I officially became a believer in the benefits weighted balls can have when utilized appropriately in a pitcher development plan. In the following years, we've been able to replicate the developmental success from 2011 in several environments. So how do weighted balls work? Well, the following is what I think I know from a decade of experience using them.

#1 Improved Health

Keeping pitchers healthy is the #1 reason that initially attracted me to weighted balls. I do not believe in sacrificing health for development. On-ramping pitchers patiently and methodically is the foundation of a healthy developmental plan.

In order to understand where weighted balls fit in, we turn to the "Physical Stress Theory" (PST), which states "changes in the relative level of physical stress cause a predictable adaptive response in all biological tissue." Physical stress is the force applied over a specific area of the body, including muscles, tendons, ligaments & bones.

I believe there are five developmental training categories directly related to PST.

1. Under-Training = atrophy (typically results in injury or under performance)

2. Standard Training = maintenance of current state

3. Optimal Training = tissue hypertrophy "tissue types increase in strength and stress tolerance when they experience stress that is greater than normal."

4. Over Training = tissue injury

5. Extreme Over-Training = death

*there have been zero cases of deaths related to weighted ball usage

For the time being we will focus on how implementing weight balls can create an Optimal Training environment. Weighted Balls, also known as overload training, create specific adaptation to imposed demands. Stimulus needs to be very clear to create specific adaptation. Utilizing weighted balls in an on-ramping program to build volume at lower intensity promotes tissue fitness, specifically to the flexor-pronator mass, the muscles that stabilize and protect the Ulnar Collateral Ligament (UCL) during throwing.

Typically speaking, I utilize a four week on-ramping program with interval throwing (one day throw, next off), three days a week. Load is gradually increased by utilizing weighted balls at low intensity and a long toss progression. This promotes arm-fitness & arm-health and allows the pitcher to gradually increase stimulus to arm necessary for specific adaptation, followed by a full day off of throwing which allows the body and arm to recover fully before returning to throw. I have found setting this foundation is imperative to sustaining pitcher health, as well as setting them up to optimize their development in the future. I am very patient with this process and err on the side of caution. I would rather have too many recovery days than work days, and have no problem extending the on-ramping period from 4-weeks to 6-weeks (even 8-weeks when necessary for the specific athlete).

Using weighted balls at low intensity during the on-ramping period allow the pitcher to increase load & allows for a very clear stimulus to create specific adaptation, "Flexor-Pronator Mass" that will promote arm health going forward.

#2 Improved Recovery

The use of weighted balls can impact an athlete's ability to recover in two ways.

The first has to do with the increased training load. Once the on-ramping phase is completed, athletes move into a load building phase. About half way into this phase, weighted balls are utilized at the end of heavy throwing days at high intensity, as a "finisher", to increase load. The goal is to make the load of training higher than the stress they will experience during the season in-game. Adding this load to the end of heavy days gives us the opportunity to build up workload so the body can continue to adapt. When faced with a lesser load during season, the body will then have an easier time recovering. It is imperative to on-ramp appropriately before introducing this phase, as well as monitor each athlete's fatigue. Many athletes overall performance numbers (velocity) will suffer during this phase while the body adapts to the novel stimulus. It is the coach's responsibility to ensure the athlete is experiencing optimal training fatigue and not over-training fatigue. This process can very tricky, and daily communication with one's athletes, athletic training staff (where possible), and monitoring of performance output numbers is of the utmost importance.

The second way I believe weighted balls can improve an athlete's ability to recover is by assisting in cleaning up their delivery. Weighted implements have been known to assist in the building of proprioception & kinesthetic awareness AKA an athlete's ability to "feel" their delivery & more specifically arm-action, (See Lucas Gioloitto 2018 off-season adjustments). For lower level athletes, weighted balls can assist in creating a more efficient arm action that puts less stress on the elbow and shoulder. This efficiency of arm-action redistributes the stress of decelerating the arm to the posterior shoulder (as opposed to the elbow or bicep), a stronger muscle group that is more effective in decelerating the arm. It is believed that when the posterior shoulder is involved in decelerating the arm, the body and arm have an easier time recovering, resulting in a faster recovery cycle.

#3 Increased Velocity

Like recovery, I believe that the use of weighted balls can help increase an athlete's velocity in two ways.

The first way weighted ball can help build velocity is by building the posterior chain.

The staple on any good weighted ball program is reverse throws. Reverse throws focus on the building of the posterior chain, or the pitcher's "breaks".

An analogy often used to describe how weighted balls can be beneficial in this area is that of a Race Car. If someone receives a Race Car with an engine capable of reaching speeds of 200 mph, but it only has 50 mph breaks. How fast are they going to drive the Race Car? Lets review some of the options:

  1. Drive 50 mph - push the breaks to the limit, allowing the breaks to dictate the speed of the car.
  2. Mainly 50 mph (unless the environment dictates otherwise) - the driver mainly sits at 50 mph unless there are long, open areas to slow down or higher speeds are needed for survival.
  3. Below 50 mph - the driver is taking a safe approach to maintenance, but is selling the car short of performance.
  4. Consistently over 50 mph - it is only a matter of time before the driver crashes and needs to take the car to the body shop.

What if that same car got an upgrade to 250 mph breaks? Lets see what our options are now:

  1. Drive 200 mph - push the breaks to the limit, allowing the breaks to dictate the speed of the car.
  2. Below 200 mph - the driver is taking a safe approach to maintenance.
  3. Push the car over 200 mph - knowing the car has 250 mph breaks, the driver is able to push the engine over 200 mph knowing the car has the ability to break safely.

Now replace the car with a pitchers arm. In the first scenario, the pitcher has a 94mph arm but 86mph breaks.

  1. Throw 86 mph - push the breaks to the limit, allowing the breaks to dictate the speed.
  2. Mainly 86 mph (unless the environment dictates other wise) - the pitcher mainly sits at 86 mph unless its the last game of the season or he needs to reach back for a little extra in a big moment of a playoff game or at a showcase.
  3. Below 86 mph - the pitcher is taking a safe approach health, but is selling himself short of some performance.
  4. Consistently over 94 mph - it is only a matter of time before the pitcher gets hurt, and potentially needs surgery.

What if that same pitcher got an upgrade to 100 mph breaks? How do our options change now?

  1. Throw 94 mph - push the breaks to the limit, allowing the breaks to dictate the pitcher's velocity.
  2. Below 94 mph - the pitcher is taking a safe approach to maintenance.
  3. Push the arm over 94 mph - knowing the arm has 100 mph breaks, the pitcher is able to push his arm over 94 mph knowing he has the ability to break safely.

Reverse throws with weighted balls allow the pitcher to build up their posterior chain (breaks) safely. For me, any program that aggressively promotes throwing (weighted balls and baseballs alike), should also aggressively promote building the posterior chain of the thrower. This is why reverse throws are a staple of many good weighted ball programs, and are often the first drill many throwers perform in their routines.

The second way weighted balls can help build velocity is by increasing External Rotation (ER) of the throwing arm shoulder.

Many researchers believe that increasing ER in the throwing arm shoulder promotes added pitching velocity.

Youth Pitchers, whose growth plates have yet to close, who throw weighted balls can experience what is known as humeral retroversion – a slight twist in the bone of the upper arm. This is the response to the stress repeatedly applied by the pitching motion to the humerus. This adaptation can lead to an increase in pitching velocity.

Athletes whose growth plates have closed, but are novel to weighted ball use, still experience an increase in external rotation of the throwing arm shoulder due to tissue adaptation. It is not as extreme as humeral retroversion but still leads in an increase in velocity.

Two important things to note regarding Increased ER of the throwing arm shoulder:

The first is, it is important that novel users of weighted balls have a conservative on-ramping process. The pitcher wants to elongate the period of time during which this humeral retroversion takes place, allowing the body time to safely adapt and compensate for the new changes within the anatomy.

Secondly, it is very important to compare Total Range of Motion from the throwing arm shoulder to the non-throwing arm shoulder. As the throwing arm shoulder increases in ER, it will lose degrees of Internal Rotation (IR). It has been documented that the Total ARC (IR + ER) of the throwing shoulder in healthy throwers mirrors the Total ARC of the non-throwing shoulder. This is yet another reason it is important to have your athletic trainer heavily involved in monitoring your pitchers daily.

Some closing notes regarding the implementation of a weighted ball program safely for your pitchers. Please remember the importance of safely and slowly on-ramping your athletes. Please have an Athletic Trainer active in your athlete's life by constantly monitoring them.

Please include physical screens and corrective exercises BEFORE implementing a weighted ball program; these screens include but are not limited to: Mobility, Stability, Strength and documenting Throwing History.

Most importantly please consult the professionals -

DriveLine Baseball

Texas Baseball Ranch

Florida Baseball Ranch


For more information regarding "Why Weighted Balls Work", please check out the following document:

The following are references from the linked article by Kyle Boddy:

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Lin, F., et al., Muscle contribution to elbow joint valgus stability. Journal of Shoulder and Elbow Surgery, 2007. 16(6): p. 795-802.

Seiber, K., et al., The role of the elbow musculature, forearm rotation, and elbow flexion in elbow stability: an in vitro study. Journal of Shoulder and Elbow Surgery, 2009. 18(2): p. 260-8.

Udall, J.H., et al., Effects of flexor-pronator muscle loading on valgus stability of the elbow with an intact, stretched, and resected medial ulnar collateral ligament. Journal of Shoulder and Elbow Surgery, 2009. 18(5): p. 773-778.

Buffi, J.H., et al., Computing Muscle, Ligament, and Osseous Contributions to the Elbow Varus Moment During Baseball Pitching. Ann Biomed Eng, 2014.

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