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Tuesday, May 17, 2011

Overload / Underload Training: How It Works & Why Ball Players Should Use This Training Method

Overload / Underload Training: How It Works & Why Ball Players Should Use This Training Method
By guest author: Steve Zawrotny

There are some, particularly online, who continue to spread incorrect and misleading information about weighted ball training. Our discussion here will deal with Overload/Underload (OU) training in general, and its application to baseball and softball in particular.

1. OU Training Defined

2. A Brief History of OU Research and Training

3. Other Sports That Use OU Training

4. The Benefits of OU Training

5. Other Baseball Experts Who Are Proponents of OU Training


Using weight-modified implements that are otherwise identical
to those used during competition

The weights of these modified tools weigh both more and less than the standard competitive weight.

Such tools allow athletes to train more precisely for their sport. Sport-specific strength and power are developed by movements with resistance or assistance that imitate the joint action of the skill - SPECIFIC RESISTANCE TRAINING. What makes this type of training so effective is that the weights of the modified tools used are heavy enough to produce a conditioning effect, yet light enough to not adversely affect the athlete's mechanical skills.

Generally, OU Training is employed to increase an athlete's POWER. Power is defined as the rate at which one can perform work, or the ability to exert muscle force quickly. This ability is related to, but distinct from strength, which is defined as the ability to exert muscle force.

As an example, strength is demonstrated as the ability to pick up a 30 oz. bat. Power is demonstrated by the ability to drive a baseball 400+ feet while swinging that 30 oz. bat.

As long as the tools used are not too heavy, mechanics are not affected, making OU Training what I call "skill-neutral." According to published data (see below) the ideal weight range for conditioning and performance enhancement is up to 20% +/- the weight of the competitive implement. I do NOT recommend using baseballs weighing more than 6 oz., or softballs heavier than 8 oz. There is some data that indicates using much heavier balls can negatively affect throwing mechanics, possibly leading to arm problems. Extra motor-units are recruited while throwing these heavy balls that are then not used when the regular competitive ball is used. As relates to our discussion here, the modified implements ball players can use are weighted baseballs and softballs, and various weights of baseball/softball bats, and/or devices attached to these bats.

Conversely, this type of training would not be useful for training other athletic skill areas, for example, shooting or throwing accuracy. OU training could help a golfer drive their tee shots further, but it wouldn't help eliminate their slice if they have one, or otherwise help them to hit straighter drives. OU training could help a young basketball player who is having trouble hoisting a basketball high enough to make a shot in a 10 foot hoop, but the shot still has to be accurate enough to go in. Accuracy training needed for a specific skill would therefore be performed apart from power work.

If I was working with a pitcher who had control problems, I would not break out the weighted baseballs and expect training of this type to help him throw strikes. I would look at his mechanics and make any needed adjustments, and possibly suggest some drill work to help reinforce the new concepts being taught. Such a player might also be working with weighted baseballs/softballs as part of their overall training regimen, but this would occur at a different time, and for the purposes of developing more power and speed behind his/her throws as well as conditioning the throwing structures of the arm.

A potential side-benefit of OU training is that a player could improve their accuracy by virtue of the increased number of reps or throws they are performing. This would be an artifact of the main goal of improving power, however, and not the main purpose of OU training.


The first research involving OU training was performed in the 1970s by the Soviet Union and East-European track and field teams. A great deal of this research has been published in prestigious, peer-reviewed journals around the world. Shot-putters, javelin, discus and hammer throwers, and sprinters were the early adopters of this training method.

Research with baseball players dates back to the 1960s. This is just a sampling of studies involving OU Training and baseball. There are dozens more relating to OU Training generally: Read more.

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