Contact Form Demo

Overload/underload Training

Overload/Underload Training is an old concept to break Speed barriers. The Overloading increases resistance and thus promotes using the big core muscles and the underload Training allows the Body to move faster than it can normally. It mostly works on neuronal aspects allowing the muscles to fire faster.

Soviet Trainers experiemented with that Kind of Training Long ago by having shot putters using heavier and lighter shots. Their studies found out that you should not go more than 20% over or under the Regulation implement because otherwise mechanics would be impaired. There is a lot of excellent Research by Coop deRenne regarding Baseball on that subject.

Note that this is an advanced Training method for breaking plateaus. I would only recommend doing this for older athletes with stable mechanics and good fitness. It is hard to make a rule but I would usually not do it before 14U or so. For younger kids working on mechanics makes much more sense.

but if you have good mechanics and some strength but batspeed is not progressing overload under load training can help.

so how is it done?

First you need a lighter bat that is about six ounces lighter than your game bat (you can use an old softball or a longer youth bat) and a bat that is about six inches heavier.

For making a heavier at use a wood bat, drill holes into it and glue fishing sinkers into it with epoxy glue. However make sure that you don’t change the balance point too much by grouping the weights around the balance point.

if you have those bats make sure that you are really warmed up. After that do some swings with the normal bat and then you are ready for the program. First do 5-6 swings with the heavy bat, then the light bat and then the regulation bat. Make sure every swing is max effort and take a little rest between the bats. Do 2-3 sets of this 3 times a week.

It is not unusual to gain 10 mph of batspeed in a few weeks the first time you do it. I went from high 60s in batspeed to 80 in about 2 months. However later the gains will be much lower because you both improve your mechanical efficiency and neuronal efficiency and those things improve rather quickly. For further improvement you might need to increase absolute strength or sometimes also mechanics. But for a quick boost this kind of training is very good especially for guys who have not trained for max effort.  Again make sure you don’t do it before you have good mechanics.

Also make sure that you get enough rest. I made the mistake of doing it daily and while gains were fast first after some time neuronal fatigue set in and I even regressed a little. 3 times a week is enough.

Mechanical aspects

Technical Aspects:

The Goal here should not be talking technique but biomechanical principles do influence how much power you can generate. You want to use as much muscle mass as possible and in the correct sequence from the ground up into the bat.

It might sound boring but we need to talk some biomechanical principles:

  1. The kinetic chain: Here is a graphic from a golf website showing the velocity graph to illustrate the point (source:


The kinetic chain works like a whip. If you crack a whip you accelerate the handle and then as you decelerate it the tip accelerates. A baseball swing works similarly. The lower body and hips accelerate first, then the trunk accelerates and finally the hands and bat. As energy is transfered from one link to the others the prior link decelerates. Basically it is hips accelerate and then as they decelerate the trunk accelerates and then the trunk accelerates an das it decelerates the bat reaches maximum Speed.

It is important that you don’t activate the next link before the prior link. The swing does not start by taking the knob to the ball but by driving the legs and hips. First the hands stay back and closely connected to the body until the hips and trunk have started to open, then the hands turn the barrell into the ball last and then follow through.

posey 1

2.The stretch shortening cycle: In good swings you can actually see that the hips and hands move in different directions for a moment to create maximum stretch. As the hips transition from the coil to the opening oft he lower body the hands are still moving back for a little moment. That creates great stretch. The hands and hips don’t go at the same time. Studies have shown that a muscle that is stretched rapidly and then immediately fires generates more power than a static muscle. For that reason a tennisplayer will do a takeback and then swing without a pause rather than just waiting with the bat back. For that reason baseball players „Load“ before they swing. The Load will be a slight counter rotation oft he hips and a slight back/up move oft he hands. To have it work best the load must be on time. Too late and you are rushed and too early and you don’t use the stretch shortening cycle perfectly.

In good swings you can actually see that the hips and hands move in different directions for a moment to create maximum stretch. As the hips transition from the coil to the opening oft he lower body the hands are still moving back for a little moment. That creates great stretch. The hands and hips don’t go at the same time.





3. Ground reaction force:

When you push against the earth, due to newtons law the earth pushes back with the same force. A Jumper pushes against the ground and the ground catapults him into the air. In baseball thus is it important to be strongly grounded as you swing.

As you load the rear leg is stable. You gather the weight against the rear leg and then coil the hips back as you stride. The rear leg is rock solid and not swaying back but resisting that coil so that you coil around/against the rear side rather than shift the weight over it. That loads the rear leg like a spring so that the rear leg then drives sideways against the ground to start to open the lower body. As the lower body starts to open the front foot is planted. First only the toe and then the heel plants which triggerst he hips to further open and then block the front side so that this side decelerates and the rear side accelerates more. That means that the ground is used on both legs to accelerate the swing.

The swing:


Now that we have talked the principles we can talk about the swing in general.

Here is a swing of Adrian Gonzalez with some interesting positions.


The swing starts with coiling the hips as you start the stride. Some players will gather their weight back before that or lift their leg and others start straight forward. As you coil try not to counter rotate the shoulders and hands too much to not lose vision to the ball. Basically you try to keep the chest facing the plate as you coil the hips although the shoulders will usually counter rotate a little. But it is important that this is driven by the hips. That also delays the hands a little so that the hands actually come back during the end oft he coil and continue carrying back after the coil oft he hips is reversed and they violently open. This creates the desired stretch shortening cycle.


As you coil you are striding forward. The rear leg is loaded and driving inward against the coiling hips. The hips start to open at toe touch. Just after toe touch the heel will plant. That fixates the front side and creates a stable axis fort he body to rotate around. The lead leg extends and the rear knee is driving in, not squishing the bug but driving sideways of the instep as long as possible and the coming up on the toe.


The back elbow was up at toe touch and the bat pointing to the sky. As the hips are opening the hands are still going back. The shoulders are not opening immediately but tilting backwards a little (start with front shoulder lower than back shoulder at toe touch and then reverse) before they start to open which increases the stretch.The back elbow is lowering and the bat is going down and behind so that it is actually going away from the plate.


The hands now finally start to be pulled forward by the trunk rotation (although they are still trying to stay back and connected to the rear side) but the bat is still going rearward, basically continuing to load the hands and forearms. The bat also lowers into the swing plane (talk about that later). The body is turned forward and just the bat is lagging.


The body is now mostly in the contact position, only the bat is lagging back. That creates a big stretch in the hands and forearms and now all the hitter needs to do is turning that bathead into the ball. The shoulders will finish their turn but basically the swing is on an autopilot now.


At contact the arms are still bent. The front arm is stretched across the chest and the rear elbow bent and tucked in into the side.


Now the arms will extend and at the very end the hands roll over. Basically extension happens because the bathead pullst he arm into extension. Since the hip rotation now delerates the hands that previously travelled in an arc around the body now go forward straighter the the pitcher but you are not trying to push the hands in a straight line. Just whip the bathead with your whole body and extension will happen.


The swing plane:

Not only batspeed is important for power but also making clean and hard contact. You give yourself the best chance to do that by matching the plane oft he pitch. A pitch will go down on a 5-10 degree angle on average and to give yourself the best chance to succeed you want to swing UP 5-10 degrees at contact. The swing will start down behind the body, but then level out and go up about two feet behind contact or so. basically the path resembles that Nike „swoosh“ sign.

Here is a great illustration that I found on youtube (source: showing the plane of world class player Shin Soo-Choo.


It is also important to not that the swing path is basically an arc around the spine. The swing is mostly perpendicular tot he spine which means that the spine is tilted over the plate as you swing so that you don’t drop the hands to hit lower balls. The spine also usually leans a little rearward at contact.

The lead arm and bat ideally form a straight line at contact that is perpendicular to the spine. The lead arm is stretched across the chest and elbow tucked into the side ideally. It does not always work like this and sometimes you need to leave that plane a little or extend the armst o adjust but that ist he ideal you should strive for.


Also keep in mind that your swing not only  needs to be fast but also be quick. Pros have times from initiation to contact of less than 0.15 seconds. Keep the barrel and hands close to the body initially for a shorter and more direct swing.

A good device to check batspeed, swing times and other features like the attack angle of the bat is The Zepp device.

More Info On Zepp Baseball

I can recommend Zepp from my experience but there are other companies who offer similar devices too.

Speed and different kinds of strength

Power is force applied in a certain time. The more force you apply over a shorter time span the more power you can generate.

of course pure power is not everything because the swing is a complex movement. You want to use as many muscle groups as possible (using the whole body) but you want to use the muscles in the correct sequence from the ground up. If the swing is out of sync that can hurt both batspeed and accuracy so learning good mechanics is important. Intermuscular coordination has to be learned but this is not the topic of this article. In this article I want to talk about how muscles generate strength.


There are different kinds of strength:


  1. Reactive strength: A muscle that is stretched dynamically will be able to fire at higher intensities. The kinetic chain sequentially stretches and fires muscles like a rubber band. Muscles can be trained to develope higher peak forces after a stretch. For that you stretch the muscle dynamically and immediately reverse. That kind of training is called plyometrics and can be highly effective in increasing power without adding mass to the body. However it has to be said that this training also creates great forces that can cause injury if not done right or without creating general physical preparedness first.

2. Intramuscular coordination: The body can’t recruit all muscle fibers at once. There is a reserve that only can be recruited under extreme stress but by training you can increase the number of motor units that can fire at the same time. Lifting big weights at low reps will train that kind of strength without gaining much muscle mass. That kind of training is done at 90 plus percent of the max lift weight and usually 1-3 reps.


  1. 3.  Muscle mass: muscle mass is not everything but given the same intramuscular coordination more muscle mass will generate more power.  So gaining more mass will help but only if you don’t sacrifice on flexibility and coordination. Still players need to increase muscle mass but not neglect other areas of training. Training for muscle mass  (hypertrophy) is usually done at 80 plus percent of the max doing 5-12 reps per set.


4. Speed strength: To develope speed a muscle must contract as fast as possible. Speed consists of many traits like coordination, technique and also the muscle fiber type but it also is related to strength. That is because the inertia of the object you are trying to move is getting the larger the faster you accelerate. Speed strength is simply trained by moving non maximal weights fast. In weightlifting usually weights of 50-70% of the max is used for training by moving the weight 3-5 times as fast as you can.

Basic fitness training

Basic fitness training:

It is important that you build a foundation before you do harder and more specialized training, especially for younger kids. Too hard training early on can lead to injuries. I would recommend starting to work with body weight excercises to bring your body in shape.

Always start with a good warmup. Run a couple poles and do some gymnastics (arm circles, jumping jacks….) for the legs and arms. There are a lot of different theories about stretching, but I would do some light dynamic stretches along with the gymnastics.

Leg work:

Running coordination drills:

This is about batspeed but running is important in baseball. Do some high knees, buttkicks, shuffles skips, lunges and other stuff. You can find a lot oft hat stuff on youtube, so I won’t really go too deep into that. You don’t need to do a lot of volume, more important ist hat you do it regularly. Two lanes of 90 feet of each drill is plenty enough.


Sprints: sprints build leg power and of course make you faster. Do a couple sprints about 90-120 feet but only after a good warmup and some coordination work. 5-6 sprints should be enough, don’t get tired.



    1. Vertical jumps: crouch low and immediately jump up. This triggerst he stretch reflex and builds explosivity. Do 2-3 sets of 5-8 reps.
    2. Standing long jump series: squat low and swing your arms back, then extend forward and swing the arms forward at the same time. As you land you crouch and swing the arms back and then immedately repeat as you land

Core work:

The core is extremely important in baseball. It transfers power from the legs to the bat.

      1. Plank variations. Do normal forward planks, side planks and even some twisted planks like this: search plank variations on youtube and don’t do the same every day.
      2. Crunches: those are disputed too but I think if you don’t overdo them they are still a solid excercise albeit not really baseball specific
      3. Straight leg pelvic twist: lay on the back, lift your extended legs and move them left of you tot he ground and then right and so on. Great excercise for the obliques. body excercises:
      1. Push ups. By far the most famous body weight excercise and rightfully so. very good pushing excercise. You can target the triceps more by keeping the hands narrower. Make sure to go all the way down and not too fast. You can increase difficulty by raising feet.
      2. Pull-ups. Great excercise but not easy to do. for starters you can do lying pull ups on a low bar: until you can do real pull-ups
      3. Band work: google throwers ten for pointers. Especially important ist he external rotation oft he shoulders for health because baseball targets more the internal rotators.

After your workout do some static stretching to not lose flexibility. Do toe touches, quad stretches, calf stretches and adductor stretches. Also do stretches fort he triceps, pecs, lats and forearms. Losing flexibility can hurt your technique and limit your range of motion causing you to not use the whole kinetic chain. Make sure to stretch the obliques too (like this for example so that you can increase the hip shoulder separation in the swing.