OVERLOAD/UNDERLOAD TRAINING: HOW IT WORKS AND WHY
BALL PLAYERS SHOULD USE THIS TRAINING METHOD
By Steven C. Zawrotny, MS, CSCS
This report is written with the intent of providing useful and accurate information for those interested in learning more about this valuable training method. 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. Baseball Experts Who Are Proponents of OU Training
6. OU Training and MLB players
OU TRAINING DEFINED
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.
OU Training is one type of Specific Resistance Training 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.
POWER = Strength X Speed
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 20% +/- the weight of the competitive implement. I do NOT recommend using baseballs weighing more than 6 oz., or softballs heavier than 8 oz. for skills or mechanics training. 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.
However, implements heavier than the 20% guideline can be used safely and effectively for strength and conditioning purposes. 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
A BRIEF HISTORY OF OU RESEARCH
involving Overload Training has been going on for decades. Underload
Training techniques became more widely known in the 1970s due to the success of 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:
1) Coop DeRenne, Kwok W. Ho and James C. Murphy. 2001: Effects of General, Special, and Specific Resistance Training on Throwing Velocity in Baseball: A Brief Review. The Journal of Strength and Conditioning Research: Vol. 15, No. 1, pp. 148–156.
2) Escamilla et al. 2000: Sports Med Apr; 29 (4): 259-272
3) David J. Szymanski, MEd, CSCS, June 1998: The Effects of Various Weighted Bats on Bat Velocity - A Literature Review. Strength and Conditioning, pp. 8 - 11
4) Coop DeRenne, Barton P. Buxton, Ronald K. Hetzler and Kwok W. Ho. 1995: Effects of Weighted Bat Implement Training on Bat Swing Velocity. The Journal of Strength and Conditioning Research: Vol. 9, No. 4, pp. 247–250.
5) Coop DeRenne, Barton P. Buxton, Ronald K. Hetzler and Kwok W. Ho. 1994: Effects of Under- and Overweighted Implement Training on Pitching Velocity. The Journal of Strength and Conditioning Research: Vol. 8, No. 4, pp. 247–250.
6) Coop DeRenne, Kwok Ho and Alan Blitzblau. 1990: Effects of Weighted Implement Training on Throwing Velocity. The Journal of Applied Sport Science Research, 4, 16-19.
7) DeRenne, C., Tracy, R., and Dunn-Rankin, P. 1985: Increasing Throwing velocity. Athletic Journal, April, 36 - 39.
8) Bagonzi, J. A. 1978: The Effects of Graded Weighted Baseballs, Free Weight Training, and Simulative Isometric Exercise on the Velocity of a Thrown Baseball. Master's thesis, Indiana University.
9) Litwhiler, D., and Hamm, L. 1973: Overload: Effect on Throwing Velocity and Accuracy. Athletic Journal, 53, 64-65.
10) Brose, D.E., and D.L. Hanson 1967: Effects of Overload Training on Velocity and Accuracy of Throwing. Research Quarterly. 38:528-533.
11) Egstrom, G.H., Logan, G.A., and E. L. Wallis 1960: Acquisition of Throwing skill Involving Projectiles of varying Weight. Research Quarterly 31:420-425.
In brief, all of the study subjects were either high school or college players. All of the studies showed an increase in throwing velocity using weighted baseballs. There were no reports of harmful effects such as joint soreness or problems with mechanics and control.
For those who are
interested, the following are the guidelines for submitting articles to several
of the the journals cited above:
"The Journal of Strength and Conditioning Research (JSCR) is the official research journal of the National Strength and Conditioning Association (NSCA). Membership in the NSCA is not a requirement for publication in the journal. It publishes original investigations, reviews, symposia, research notes, and technical and methodological reports contributing to the knowledge about strength and conditioning in sport and exercise. All manuscripts must be original works and present applications to the strength and conditioning professional or provide the basis for further applied research in the area. Manuscripts are subjected to a “double blind” peer review by at least two reviewers who are experts in the field." [The JSCR was formerly known as the Journal of Applied Sport Science Research.]
The American Journal of Sports Medicine is the official publication of the American Orthopaedic Society for Sports Medicine. Instructions to authors who are submitting articles includes the following: "Manuscripts must not be under simultaneous consideration by any other publication, before or during the peer-review process."
Research Quarterly for Exercise and Sport publishes research in the art and science of human movement that contributes to the knowledge and development of theory either as new information, reviews, substantiation or contradiction of previous findings, or as application of new or improved techniques.
Instructions to authors who are submitting articles includes the
following: "Because reviews are blind, include a second title page with only the title, running head, and page header."
OTHER SPORTS THAT USE OU TRAINING
Over and underloaded implements and techniques are used very effectively by athletes in many big-time sports to augment performance:
Olympic Track & Field: heavier and lighter discuses, javelins, shot balls (shot putters) and hammers; sprinting with resistance, such as pulling weighted sleds, wearing weighted vests, and downhill running on a slight downward slope, being towed while running, and running on a high speed treadmill (overSPEED training).
Olympic Swimming: wearing swimming gloves that allow for more water to be pulled during an arm stroke; swimming while dragging an implement or otherwise artificially producing drag on a swimmer.
The NFL & NBA use many of the same track and field training techniques to improve the speed and power of their players. Heavier footballs (over the standard 15 oz) are thrown by quarterbacks for arm conditioning; the receivers catching these heavy footballs develop increased strength in their hands and forearms. Heavy basketballs are used by basketball players in various shooting and passing drills, as well as weighted vests for running and jumping drills.
The NHL employs resisted and assisted sprint training with its skaters.
Boxers train with different weights of gloves and bags.
Note that ALL of
these training implements are used to improve POWER and/or SPEED through the joint
range-of-motion (ROM) in the activity being trained, which can lead to enhanced
These major sports with their highly paid athletes have employed OU conditioning techniques safely and effectively for years.
THE BENEFITS OF OU TRAINING
Increased strength/endurance in the arm structures used to throw a baseball or softball
Appropriate strength and conditioning regimens, such as OU Training, can reduce and even prevent arm injuries related to throwing by increasing STRENGTH/ENDURANCE. Increased Strength - helps prevent injury. Increased Endurance - helps maintain throwing velocity, allows for more pitches to be thrown before tiring.
The muscles, tendons, ligaments and bones (even nerves) of the shoulder and arm in general will positively adapt to an appropriate increase in training load, resulting in a greater ability to apply force. These changes take place as follows:
Minimal Essential Strain (MES) is the amount of stimulus required to produce anatomical changes in the body that enable it to positively adapt to the increased workload imposed on it. MES produces adaptations in all of the aforementioned structures. Some of the means by which these adaptations occur are similar for these structures, some are different. Increased bone deposition, for example, depends on (amongst other factors) the age and condition of the bones involved in training. Anything from walking to heavy resistance training can be a sufficient strain to stimulate new bone growth. For increased muscle fiber deposition (hypertrophy/hyperplasia), walking is not a sufficient stimulus while heavy resistance training is.
Force application is important in muscular endurance (Jones 1974) and speed of movement (McCloy 1936, Nelson and Fahrney 1965; Nelson and Jorden 1969). Force is particularly important in developing power (Berger and Henderson 1966). Ultimately, power is what ballplayers are after.
The following list is an overview of the upper body muscles used and their actions during an overhand throw:
Triceps - extends the elbow during the acceleration phase of an overhand throw
Pectoralis major (internal rotator muscle) - horizontally flexes, inwardly rotates, and adducts the humerus (upper arm) bone (amongst other actions)
Pectoralis minor - forwardly tilts, depresses, and downwardly rotates the scapula. This helps stabilize the scapula during an overhand throw
Latissimus dorsi (internal rotator) - during the acceleration phase, extends, horizontally extends, and inwardly rotates and adducts the humerus. During the deceleration phase, extends and horizontally extends the humerus
Deltoids (anterior [internal rotator], middle, and posterior heads [external rotator]) - abducts, flexes, extends, horizontally flexes and extends, and outwardly rotates the humerus. The anterior head assists the pectoralis major during shoulder transverse flexion, moving the upper arm toward and across the chest and midline of the body
Teres major (internal rotator) - extends, horizontally extends, inwardly rotates, and adducts the humerus
Rotator Cuff, internal rotators - Subscapularis muscle horizontally flexes, adducts, inwardly rotates and extends the humerus. Supraspinatus muscle inwardly and outwardly rotates the humerus during arm acceleration and deceleration
Rotator Cuff, external rotators/decelerators - teres minor flexes, extends, horizontally extends, outwardly rotates and adducts the humerus. Infraspinatus - flexes, extends, horizontally extends, outwardly rotates and adducts the humerus.
Muscles in red are overhand throwing ACCELERATORS; muscles in blue are throwing DECELERATORS. Accelerators contract concentrically to help speed up and move the arm forward during a throw to the release point, and the decelerators help slow down the arm after ball release by contracting eccentrically. The accelerators are larger, more numerous (six), and more powerful than the decelerators (three). These differences in activity and anatomy around the shoulder complex have important training and conditioning implications.
Assuming proper pitching mechanics,
all of these muscles are well conditioned by OU training. This is very
important because these upper body muscles are a major factor
in velocity production during an overhand throw. Toyoshima et al., in a
study published in the journal Biomechanics IV, demonstrated
that 46.9% of the velocity of the overhand throw could be attributed to the
stride and body rotation, with 53.1% due to arm action. So it's basically
a 50-50 contribution between the trunk and the arm. Appropriate training
of both body "areas" should be part of a well-designed strength and
conditioning program for baseball pitchers and any overhand thrower. You
can learn more about how to do this here.
Such training must conform to the following two guidelines:
1) The training load is sufficient to produce the desired training effect, yet not so great as to negatively impact throwing (or hitting) mechanics.
2) The thrower's program introduces OU training gradually and systematically, employing a training principle known as Progressive Overload (Clarkson & Watson, 1990). This principle states that "strength and endurance cannot be increased unless the muscles are stressed beyond their normal workload. To increase the workload, increase the frequency, duration and intensity of your exercise program."
There are three variables to manipulate to induce a training effect in any type of exercise or conditioning: The intensity (workload) of the workout, the duration (or length) of the training session, and the frequency of workout sessions. To effectively and safely increase throwing velocity, intensity is increased by using 20% +/- OU balls, duration is increased by gradually increasing the number of OU throws performed with each workout, and frequency is increased by the number of days of throwing workouts. Arm/shoulder structures trained in this manner are more capable of handling the regular competitive game stress, which is less than that imposed by OU conditioning. An arm conditioned for making numerous throws with a 6 oz ball will more than likely out-perform an arm trained only to work under a 5 oz. load (ability, mechanics and over-use considerations aside).
This is best summed up by way of the well-known conditioning principle S.A.I.D. - Specific Adaptation to Imposed Demands (Wallis and Logan, 1964). This principle states that the body will adapt to stress imposed on it (as long as it is not excessive, in which case the body breaks down) and will not adapt beyond the scope of that stimulus. This principle forms the basis for any type of workout performed in all of sports and physical activity. One safe and effective way of doing this is with OU Training, employing the aforementioned guidelines.
Improved on-field performance - increased throwing velocity (or bat speed).
This conditioning method, known as overSPEED (or assisted speed) training, uses techniques that increase movement speed through the joint Range Of Motion (ROM). As discussed above, Olympic track and field athletes and other sports have long employed this type of training very effectively and safely.
In the case of baseball and softball throwing, this attribute is developed by throwing a ball weighing 20% less than the competitive ball. Because the ball weighs less, the arm traverses more quickly through its ROM, producing greater arm-speed movement. The greater the arm speed, the greater the ability to apply force to a ball during a throw. Force application is one of the keys to greater throwing velocity (the other being the length of time of force application). Throwing lighter balls has been shown, both clinically and on the ball field, to be one of the best means of increasing throwing velocity. Similarly, swinging appropriately lighter bats helps develop increased bat speed, producing greater hitting power.
A note on "light" ball training, high school and older players: This can be an excellent way for pitchers in particular to get a good amount of throwing in between starts with less stress on the arm. For youth ball players - why do we make lighter bats for younger ball players, yet make them use the same 5 oz ball that guys like Roger Clemens and Randy Johnson throw? That Little League fields are smaller makes little difference when it comes to the length of some of the throws that young players have to make. These little arms still have to generate a great deal of force to propel the ball. In many youth leagues around the country, 13 year olds have to pitch at 60' 6" and play on major league sized fields. Underweight balls (4 oz.) are a GREAT tool for players of all ages.
Keep in mind that while an ounce may not seem like much of a difference, it actually represents a 20% change in the training load, which is very significant. It is analogous to asking a weight lifter training with 300 lbs. to now use both 360 lbs. and 240 lbs. during workouts, either of which can make quite a difference in the training results.
Enhanced neuromuscular conditioning.
According to Vern Gambetta, Director of Athletic Development for the New York Mets, the primary source of fatigue in baseball pitching is not metabolic, but neural. The metabolic demands - conditioning - are just not that great in baseball or softball. Don't misunderstand - I'm speaking here of the skills required to be a good hitter or pitcher. Being well conditioned is still important, as this will at a minimum help prevent injury, but no doubt you've seen players like John Kruk, David Wells, Tony Gwynn, and others. High level performers who are not particularly well conditioned.
Neural fatigue occurs at the motor-unit level. In the act of pitching, for example, the Central Nervous System sends a nerve impulse to a motor unit (MU) in the shoulder involved in this process. The ability of these MUs to transmit these signals, with optimal frequency and speed, diminishes over time, leading to slower and weaker muscle contractions.
In baseball pitching, throwing muscles and tendons in the shoulder are stretching and contracting repeatedly while accelerating and decelerating the arm during an overhand throw - constant biochemical activity at the neuromuscular junction. As neural fatigue sets in, it becomes manifest in mechanical problems. For example, a pitcher dropping their shoulder later in the game, leading to a loss of control or velocity. The tough thing is, this "fatigue" is usually not felt by the pitcher, but it occurs nevertheless.
This is where proper conditioning (OU Training) comes in. Research has shown that neurons adapt to stress much like muscles do. Motor neurons exposed to high-frequency impulses end up with more developed neuromuscular junctions which appear more capable of handling high-intensity impulses better than those not exposed to similar stress. The S.A.I.D. principle in effect again.
Does this mean OU
Training is fool proof, and has never harmed a player? Of course
not. Most any type of conditioning, performed incorrectly, can cause
problems or injury. Throwing itself, be it footballs, baseballs, rocks or
whatever, has harmed many a throwing arm. Running is the cause of many knee and
ankle injuries. Shoulder problems amongst swimmers are common. Ice
skaters often suffer from some very painful leg ailments. I could go on,
but you get the point. All of these injuries and problems occur as a part
of the athlete's regular practice and competitive activities. Performing them properly minimizes the risk, of
course. So does a variety of strength and conditioning methods, including
BASEBALL EXPERTS WHO ARE
PROPONENTS OF OU TRAINING
Dr. John Bagonzi. Former pitcher with the Red Sox. Known as the "Pitching Professor" and author of the book, "The Act of Pitching."
Dr. Tom House. Former pitcher with the Rangers. Author/co-author of several books, including "The Winning Pitcher" and "Power Baseball." Personal pitching coach to Nolan Ryan, Randy Johnson, Mark Prior, and others. Co-founder of the National Pitching Association.
Dr. Coop DeRenne. Former professional player, instructor and consultant to the Chicago White Sox and Texas Rangers. Probably this country's leading baseball researcher, supervising 16 hitting and pitching warm-up, biomechanical, and visual research projects using over 600 amateur and professional hitters and pitchers as his subjects. Co-author (with Tom House) of the book, "Power Baseball" and other baseball training books.
Steven Ellis. Former pitcher with the Chicago Cubs, author of the book, The Complete Pitcher and a top baseball pitching instructor in the Chicago area.
ASMI - The American Sports Medicine Institute.
Vern Gambetta, President of Gambetta Sports Training Systems. Currently the Director of Athletic Development for the New York Mets and former Director of Conditioning for the Chicago White Sox. Performed biomechanics research jointly with ASMI involving top White Sox pitchers which led to the development of throwing programs using footballs and overweight and underweight baseballs.
All of these experts possess impeccable credentials and favor some type of weighted ball training. Please note that my referencing the aforementioned individuals/organizations does not constitute an endorsement on their part of my training methods.
OU TRAINING AND MLB PLAYERS
While OU Training is not widely used by big league pitchers, primarily because of unfounded fears and misinformation regarding this conditioning method, it has been and is currently used by some. In 1987, University of Hawaii/Manoa pitcher Derek Tatsuno dominated college baseball, setting what was then an NCAA record with 541 strikeouts in 402.3 innings for his three year career. His conditioning regimen included regularly training with weighted baseballs. Named to the All-Time All-Star Team of Collegiate Baseball America, Tatsuno was the first college 20 game winner and had a career record of 40-6 and a 2.04 ERA. A second round pick of the San Diego Padres, he reached the major leagues with the Milwaukee Brewers in 1982.
The aforementioned author, Tom House, trained with weighted baseballs during his collegiate career at USC and as a major league pitcher.
Steven Ellis, a former pitcher with the Chicago Cubs, used 4, 5, and 6 oz baseballs to add 6 mph to his fastball, going from 90 mph to 96 mph.
And at least one current major league pitcher trains with weighted baseballs. Six-time All Star Mariano Rivera of the New York Yankees was shown on national TV in Game 4 of the 2004 ALCS warming up with a weighted ball. It's a part of his regular throwing and warm-up routine. If a guy like Rivera uses weighted baseballs, it's likely that other players are using them as well.
As for hitters, Dave Hudgens, hitting instructor for the Oakland A's, teaches overload training principles. Among his students and endorsers are All-Stars Eric Chavez of the A's, 2005 All-Star Game MVP Miguel Tejada of the Baltimore Orioles, and Luis Gonzalez of the Arizona Diamondbacks.
Bob Alejo, former strength and conditioning coach of the Oakland A's and now the Personal Conditioning Coach of NY Yankee's Jason Giambi, suggests the following regimen to increase bat speed: "Use a bat that is only a few ounces heavier than your regular bat. Try to use the same length as well. This way the swing will be the same, but because of the added weight, you will be increasing power with your normal swing."
Clearly, OU training is effective not only for younger, growing players, but physically mature players at the highest levels of the game.
(C) 2005. All Rights Reserved. Quotations with attribution
permitted. Cite source as Steve Zawrotny's BASEBALL FIT
Hitting & Pitching Academy - www.BaseballFit.com
The information contained herein is the opinion of the author
based on his personal observations and years of experience.
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