Training with Weighted Balls to Improve Throwing Velocity

Training With Weighted Balls to Improve Throwing Velocity

Weighted balls will improve your throwing velocity. Whether you are a pitcher, infielder, or outfielder, having an extra mph behind each throw will improve your game. A great way to improve throwing velocity is through the use of over and underweight balls. To some, this sounds like a controversial topic since we’ve all heard mixed reviews on over and underweight ball use. I can only hope to dispel those myths by the end of this article, and show you how over and underweight balls are a great way to get a few more mph every time you let the ball fly.


Increasing Throwing Velocity With Weighted Balls

The improvements in throwing velocity associated with over and underweight implement training can be explained through the force velocity relationship. The force velocity relationship suggests there is an inverse relationship to the velocity and force being moved. In other words, greater velocities are achieved when moving lighter loads, and greater force is needed when moving heavier loads.


To optimize your performance both aspects of the force velocity relationship should be trained. This means training at high velocities and high loads. The most specific way of doing this in the baseball and softball world is through the use of underweight and overweight balls. Underweight ball training will improve the velocity component of the force velocity relationship, while the overweight ball training will improve the force component. Ultimately, this will shift the force velocity curve up and to the right, improving throwing velocity by two separate training concepts.

Overweight Balls - Improving throwing velocity 

As previously mentioned, training with overweight balls requires a greater amount of force to be generated when compared to throwing a standard baseball or softball. Studies conducted by Derenne et al. and Brylinsky et al., have found significant improvements (3.75 mph, 1.5 mph, and 10 mph) following overweight implement training. It is hypothesized that training with overweight balls will causes a shift in muscle phenotype, shifting from type IIx to IIA, and can also improve rate coding. Translation, you or your baseball and softball players will be more explosive and be more efficient with the musculature used while throwing.

Studies that have shown significant improvements in throwing velocity used weighted balls no more than 20%, (6 ounce baseball), above the standard weight of a baseball, and 25%, (9 ounce softballs) greater than the standard weight of a softball.

The research does show that there are limits to the amount of load used while training with overweight baseball and softballs. Based on the force velocity relationship, baseballs or softballs that are greater than 20 or 25% of a standard ball will cause negative adaptations. The force will be too great and actually slow down your arm speed, ultimately decreasing throwing velocity.

Underweight Balls - Improving throwing velocity

As mentioned above, training with underweight balls will allow for greater arm velocity, and will train the velocity component of the force velocity relationship. Studies using underweight ball training have found 3 mph, 4.72 mph, 7.5 mph, and .89 mph increases in throwing velocity. The improvements in throwing velocity associated with the throwing programs are hypothesized to be associated with a shift in muscle fiber phenotype, shifting from IIX to IIA. The goal of underweight training is to increase arm speed, but the tricky part is testing arm speed. The best way to assess if there was an improvement in actual arm speed would be to measure changes in the speed of the arm using high speed cameras, however, no studies did this. Although arm speed measured was not measured, there were still significant improvements in throwing velocity compared to the controls, which cannot be ignored.

Similar to training with overweight baseballs, there are also guidelines for the proper weight underweight balls ball should be. The greatest improvements in throwing velocity were found when the ball weighed 20% less than a standard ball. This would be raining with a 4 ounce baseball or 5.5 ounce softball.

Improving Throwing Velocity - which to use

Using a combination of both overweight and underweight baseballs or softballs has been shown to be the most successful way to improve throwing velocity. This should not come as a surprise based on the proposed mechanisms of overload of speed and overload of force.  

Research by Derenne et al. compared the use of overweight, underweight and both over and underweight throwing program in college and high school pitchers. Of the three training interventions, the overweight and underweight throwing program showed the greatest increase in throwing velocity, ranging from 4.4-6 mph.

Proper Volume of Throws for Weighted Balls

You can’t listen to a baseball game with hearing the words "pitch count". The idea behind the pitch count is obvious; maintain the health of the pitchers arm. When it comes to training with weighted balls, a pitch count is also really important. Of the studies that saw significant improvements in throwing velocity, the volume of throws increases in a linear fashion. In other words, volume steadily increased over the 10 week period, taking the fewest throws the first week, and the most the last week. A throwing program of this type will maintain progressive overload while preserving the arm health of the baseball or softball player.

Total throwing volume of the studies did not reach over 242 throws per 3 day training period. Moreover, most training days involved 60 to 80 throws.

The volume of over and underweighted balls was seen to be most effective at a ratio of 2:1 weighted to standard ball. For ever throw with a standard ball you would take 2 throws with the over or underweighted ball.

Here is a quick example of a 4 week training program (S=Standard, OW=Overweight, UW=underweight)

Week 1-9s, 18ow, 18uw, 9s

Week 2- 10s, 20ow, 20uw, 10s

Week 3- 11s, 22ow, 22uw, 11s

Week 4- 12s, 24ow, 24uw, 12s

The benefit of volume and its effect on a throwing program is the result of an improvement in ATP-CP energy system and improvement in neuromuscular efficiency on repeated attempts. The more highly trained your phosphagen system is, the greater the ability to maintain and restore the energy needed for each throw. This leads to maintenance of velocity over an extended period of time. Likewise, the volume of throws will improve coordination between throws. As volume increases, form tends to get worse. (This is just one of the many reason it drives me nuts when people do massive amounts of plyometrics at once) With that being said, to be able to maintain your throwing mechanics and velocity in each outing, you have to train yourself to be able to handle that volume.

The risks of training with Overweight and Underweight balls

There seems to be a lot of misconception about the risks of training with over and underweight balls. Often times, the feel of an underweight ball is associated to the feel of throwing golf ball. This is far from the truth if you are using the recommended weight that has been shown to improve throwing velocity. If you throw a 2 ounce baseball it will feel like a golf ball, throw a 4 ounce baseball and there is a minimal difference.


Over weight balls are associated with the idea of shoulder injuries and a drastic change in throwing mechanics. Speaking from experience, and results from studies, I have never read or heard of an injury while working within the recommended ranges in ball weight, that being 20% above or 20% below a standard baseball or softball. The scariest part of pitching with an underweight ball is catching the thing - because it has a crazy amount of movement when you release it. 

It would certainly be possible to see negative adaptations in your throwing mechanics or performance when athletes use overweight balls. As previously mentioned, there is a definite risk of decreasing throwing velocity and a chance of changing throwing mechanics if you train with balls 20% heavier then normal. Similarly, training with a ball less than 20% of a standard ball, although not studied, common sense will tell you there is a risk for a change in mechanics, changing the timing between yours hips and ball release.

Avoiding the risks of training with weighted balls is relatively simple. Train with someone who can make sure you’re using them properly. There is a risk associated with everything you do while training. Every time you lift a weight there is a chance of getting hurt. This doesn’t mean you don’t lift, it means you do it with someone who knows what they’re doing! Train with your brain!


Take home messages.

Based on the research and experience training with weighted balls, these implements are definitely an alternative way to improve throwing velocity. Here is a recap of what we learned.

1. Overweight balls has been shown to significantly improving throwing velocity by training the principle of overload of force.

2. Underweight balls have been shown to significantly improve throwing velocity by training the principle of overload of speed.

3. Training with overweight and underweight balls has been shown to be the most effective way to increase throwing velocity by training both overload of force and overload of speed.

4. To see significant improvements in throwing velocity training should be done at a ratio of 2:1 weighted ball to standard ball. For example 9 standard throws 18 over weight 18 underweight then 9 standard, is an appropriate throwing program during the first week of training with varying weighted balls.

5. Greater than 60 throws per week is needed to see an increase in throwing velocity when training with weighted balls.

6. Although many people believe there is a risk associated with overweight and underweight ball training, staying within the 20% range will ensure safety. Risk increases as the percentage deviates from 20%.

If you can throw a standard baseball or softball without pain, you’ll be able to throw an over or underweight ball with pain. Get out there and let it fly. Stick to the guidelines suggested above and trust your training. The benefits are right around the corner! (well maybe not 102 mph)