Strength Training

Overweight & Underweight Implement Training

By Christine Camozzi


Download article here.

Key Words: Overweight implement, Underweight implement, specificity, transfer of training

Next time you are driving on the highway, think about the fact that an average baseball pitch, handball shot, or tennis serve produced by an athlete would travel faster than you. In 2013, the fastest moving object in sport was recorded with a shuttlecock traveling at 493 km/hr after a badminton smash. Athletes continue to impress us with incredible throwing and swinging abilities that push the limits of implement speeds and distances. If your sport requires throwing, swinging, or passing you understand that high speed and strength is necessary for successful performances. Overweight (OW) and Underweight (UW) Training can assist in preparing athletes for an increasingly competitive field of play.

OW and UW training is a specific type of strength training that involves completing your sport’s movement with implements (e.g., balls, rackets) that are heavier or lighter than the normal implement weight. The goal of this specific training is to increase strength and speed during competitive play. This training method has traditionally been used in field throwing events, however, it also deserves a place in other sports’ training programs based on research results:

Before you pick up the heavy ball, there are necessary considerations before integrating this specific training method appropriately.


Is there an age limit?

OW and UW training is best used with athletes who have a firm grasp on their sport’s technique. Athletes of a low training age who are still strengthening the technical skills of their sport would benefit by mastering their sport’s skills and building full body strength first before starting OW or UW training. It is also important to think of the confidence of the individual. If they are still learning how to be competent in their sport and working on getting stronger, asking them to now handle a different weighted object may set them up for failure and lower their confidence. In a study using OW implements with high school throwers, researchers found that throwing speed only increased if the athletes had a high level of strength prior to starting the OW throwing program. Everyone responds differently to training and even if two individuals are the same age and competing in the same level of competition, they may not be able to handle the same load.


Why Does It Work?

Next time you complete an exercise with a dumbbell or barbell, take note of how you slow down at the top of the movement to safely bring the dumbbell or barbell back to a starting position. The difference with OW and UW training is that athletes can push the implement and increase their speed through the entire motion without having to slow down. This allows for further strength and speed development that transfers to the movements of their sport.

General strength training is important for overall athlete development and builds muscles to set a base for athletes throughout their season, however, training as specifically as possible becomes important to enhance sports performance. The more we can design specific training programs that resemble the technical, environmental, physiological, and psychological conditions faced during competition, the better we can transfer athlete’s S&C training to sport’s performance. Therefore, OW and UW training can be viewed as a specific training method.

Without taking the time to consider how to create a specific training program, we place athletes at risk of negatively transferring their S&C training to sports performance. This means that athletes could worsen their performance rather than enhance their performance. For example, elite tennis players completed 6 weeks of OW training by completing a series of forehand drive motions with medicine balls. This group increased their ball speed, but their shot accuracy declined. Another group of elite tennis players used an OW racquet for their forehand drives. This group increased their ball speed without decreasing their accuracy. This was likely because the implement was more specific to tennis than completing a forehand drive with a medicine ball.

We can help create sports specific OW and UW training programs that provide positive transfer when the following questions are considered:

  • Size of the implement. How similar is the width of the implement to the standard implement (e.g., wider softball vs baseball)?
  • Feel of the implement. How similar is the grip material to the standard implement (e.g. rough grip basketball vs smooth volleyball)?
  • Weight of the implement. Is it too heavy or too light compared to the standard implement? (e.g., 8lb med ball vs a handball)?
  • Movement with the implement. How will the athlete move with the implement so that it replicates how they would move with the standard implement (e.g., treading water and throwing an implement vs standing on dry land and throwing)?
  • Environment that surrounds the athlete. Will the athlete be projecting the implement to a target like they would in their sports environment (e.g., Throwing a ball straight up or throwing a ball to reach a partner during a routine)?


What about injuries?

Too much stress in too short of time increases an athlete’s chances of injury, regardless of what this stress is. Introducing anything into training will add a new, but not necessarily bad stress on the body. Therefore, adding OW or UW implements into a training program will change the stress on the individual, so designing the program thoughtfully can help athletes adapt and increase their chances of staying injury free. One baseball study that reported injuries from OW training programs started used OW balls that were 3 to 6 times heavier than the standard weight. Ensure that you teach proper warmups, strengthening programs (especially for the shoulder joint) and most importantly, progress volume or intensity by no more than 10% each week. Volume can be the total number of throws in a week or total training hours. Intensity can be measured by the total load (weight of implement) each week.

Here is 10% volume progression example for a Female Wheelchair Basketball OW Training:

Heavy or light, which is right?

Research has shown that both OW and UW training can increase implement speed and distance but deciding on which one is right comes back to your goals.

While OW training can increase speed, it has a more positive effect on building strength. Elite male handball players using an OW training improved their throwing speed, muscle size and maximal strength compared to a training group who used a standard handball and found no significant changes in strength. Try placing OW training in the preparatory stages of the year when athletes are building their strength. Ensure that technique isn’t affected negatively by keeping the weight at or below 20% of the standard weight of the implement.

UW training more positively affects the movement speed than strength development. Be mindful that there should be a balance between using UW training as individuals can also change their technique if they are only ever training with something lighter than standard. This can be demonstrated in an UW implement program with Cricket players who found that using too light of a ball slowed down ball speed due to a change in aerodynamics (the way air moves around things). As training shifts to the preseason, try using UW training to transfer the built strength to more technical and speed aspects of the sport. Keep the weight at or below 20% lighter than standard weight.

If you have access to a speed gun, another way to choose the appropriate weight of your OW or UW implement is to measure a change in implement release speed of about 5% than the release speed reached with the standard implement. For example, if a baseball athlete averages a 20 meter per second pitch, an OW or UW ball that creates a new release speed of about 19 meters per second or about 21 meters per second would be appropriate (5% change decrease or increase). If you notice too large of a change in speed, it may be a flag that the OW or UW implement you are using could be altering technique and result in negative transfer of training. An example of this can be seen through sled towing which is a popular sport specific training method for sprinting. One study found that when the sprinting athletes towed a weighted sled that changed their speed by 10%, their sprinting technique deteriorated.

The guidelines below can help you find your balance between using OW and UW implement training.

Where do I find OW and UW implements?

The following ideas are suggestions to help you locate OW and UW implements provided that they are appropriate in size, weight, feel and don’t affect the athlete’s technique. The chart below can help with finding an implement that is heavier or lighter than your implement’s standard weight.

  • Use the other sizes of your sport’s implements or an implement from another sport. For example, a Male Wheelchair Basketball athlete wanting to use UW training could use a Size 6 basketball.
  • Use a ball from a different sport. For example, a water polo player could use a soccer ball for UW training.

Some sports sell OW and UW versions of their implements online, however, be cautious of some versions as these tend to be much greater than the standard weight.


OW and UW training can assist in improving speeds and distances across several throwing sports if programmed appropriately. Think about the development of the athlete first and then decide upon the goals of your program to determine when it is appropriate to include UW and OW training into your program.


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James Brough Director, Performance Pathways 905.299.1389