Category Archives: Strength

The Hips in the Kinetic Chain

The hips play a crucial role in transferring forces from the ground, up through the body and out into the racket. The role they play is a fundamental one in striking sports.

Here is a video of my 3 year-old son swinging a 26 inch racket two-handed. Without even knowing it he is learning how to use the hip in this manner.


Serve Power Exercises

The serve is probably the hardest thing to work on at home but the trophy or power position is one thing that you can improve upon. Below is a video of some exercises I have been doing at home with an aerobic step and bands.

Also look back at the series I did on serve technique:


Low Box Exercises

If you have an aerobic step at home here are some great exercises you can use to work on the ability to load and explode with the legs. And don’t forget to do your shadow swings and cover some ground laterally. This quick accelerations and decelerations are easy to practice at home and something that gets missed without playing points and sets.


The Hips Are The Engine

This post is applies to everyone but it is aimed at those working with young kids especially. The ability to create rotational power is a natural movement pattern for the human body. In the video below I use an 8 Board (developed by fellow tennis coach Jack Broudy) to demonstrate how the hips are the engine for rotational power. Developing good tennis strokes is directly related to being efficient at this movement pattern. I am not even sure if the 8 board is still in production. I have had mine for a while but it has been a fantastic teaching tool because it allows you to feel the movement.

Now for those of you working with little ones this is my son using a full size racket hitting off an air tee in my driveway. If you put relatively heavy things in kids hands and allow them to experiment with swinging it you will be amazed at how quickly they get the rotational power movement. This is why I steer people away from light aluminum rackets and to heavier 25, 26 and sometimes even 27 inch rackets. Small light ones can be easily swung with just the arm but with something heavy the body is forced to use the hips and that is what you want for the foundation of a tennis stroke in the long term.


Serve Power Sources

The serve is the most complex motion in tennis by far.  These two videos are aimed at explaining the 2 main sources of power.  First, we start with the lower body and look at how to load the legs properly.  Second, we look at what I think it the most important power generator in the serve, internal rotation of the arm.  Everything that occurs with the legs is designed to maximize the speed of internal rotation.  It all the comes together at the point of contact and we look at how important the angle of the racket and arm are to transferring power into the ball.  These are elements all great servers have in common.

Ending The Early Specialization Debate

I was just talking to the parents of a fairly elite 10 year old swimmer in how to deal with the issue of early sport specialization. They were concerned their son is spending too much time in the pool but at the same time worried he will lose his edge if he does not swim enough.  I immediately saw the parallels to what tennis parents and coaches experience and it inspired me to write this post to help those of you out there going through the same issues.

In tennis it is without a doubt true that early sport specialization is linked to overuse injuries, prematurely peaking careers, and plateaus in player development.  It is fairly common to see the best tennis players at the age of 10 go on to later be plagued by injury, hit a roadblock in development, and burn out.  While at the same time it is also true that you must be a fairly decent player at younger ages and regularly play tournaments if you want a shot at doing something special.  If you understand tennis you know how important technique is and that players must hit a countless number of balls to lock in their strokes.  The end result is that we end up at the paradox of “how do I hit a lot of tennis balls and not specialize early on?”

Being both a tennis and physical preparation coach I have a unique perspective because I see both sides of the argument.  I am actually not against deciding on one main sport early on provided a long-term athletic development approach is taken from the beginning.  I believe the odds are good that you can specialize in making tennis your main sport at a young age, remain injury free, and continue to break through to new levels of physical and tournament performance.  The key to doing this is to understand the role strength and conditioning plays in tennis player development.

As I said before tennis is a sport that requires a lot of time spent hitting tennis balls.  If you spend a lot of time on the court you will get very good at tennis specific skills.  The goal of a tennis player is to then accumulate as much tennis-specific volume as possible on an annual and multi-year basis.  To clarify, by tennis-specific volume I mean hitting tennis balls or playing matches because being on the court is as specific as it gets.

This would lead one to conclude that specializing early and spending as much time on the court as possible is the way to go.  However, you must understand that in order to accumulate as much tennis-specific volume as possible a player’s body must have the fitness to support such a high volume of training.  This is where most people miss the boat.  They have juniors accumulating a ton of volume hitting balls and playing matches but their bodies cannot handle it.  The high levels of specific volume lead to better and better tennis but at the same time all the stress slowly but surely accumulates, wears down the body, and injury occurs and/or performance suffers.  This is why strength and conditioning or general physical preparation is so important.

The ultimate goal of strength and conditioning in tennis is to achieve a high enough level of fitness to support all the necessary specific training volume and recovery from it.  Sure strength and conditioning will make a player bigger, faster, stronger, and allow them to express their strokes at a higher level.  However, in a technical sport like tennis the best way to improve your skills is to hit tennis balls and lots of them.  The trap people fall into is that they think if they keep hitting more and more tennis balls they’ll continue to improve and they will but without a strong base of fitness to support that amount of specific volume, and the ability to recover from it, it is only a matter of time before injury or burnout occurs.  Achieving this level of fitness takes a long time and it is only achieved through a variety of movement patterns and training methods.

So to answer the paradoxical question of “how do I hit a ton of tennis balls without specializing in tennis” is to take a long-term athletic development approach from the very beginning.  Begin with the idea that tennis is going to be the main sport and hit a lot of tennis balls while at the same time working on all aspects of fitness (coordination, balance, strength, conditioning, etc.).  Over time you will gradually build up the fitness to support hitting more and more tennis balls and the ability to recover properly from doing so in order to stay injury and burnout free.

If you really want to do this right you have to educate yourselves or get with a coach who truly knows what they are doing because strength and conditioning looks very different at different ages and the process is unique to each child.  For example, strength and conditioning in general for an 8-year-old involves playing tag, crab walking, climbing, and free play to improve conditioning, agility, coordination and strength.  While strength and conditioning for a high school junior will involve running to develop the aerobic energy system, lifting weights to develop strength, or doing more of what comes to mind when you think of traditional fitness.  But making an 8 year old run hill sprints or hit the weight room isn’t going to get the job done.  In fact, inappropriate training will only increase the odds something bad will happen.

Let me know what your thoughts are in the comments below and if you have any questions add them as well, I’ll be happy to answer them.

For those coaches and parents out there who are looking for more information the International Youth Conditioning Association (IYCA) is launching a product this week called Long-Term Athletic Development.  It is a darn good resource to have if you are working with kids and thinking long-term in developing them.  It also happens to be on sale this week for $99.

Off-Season Training for In-Season Performance

This is an article I wrote for a sports publication that is set to go out over the summer.  Even though it is not tennis-specific its worth a read…

“The more you sweat in times of peace, the less you bleed in times of war,” is a saying that is certainly full of wisdom. Training in the off-season is one area where athletes can get a tremendous bang for their buck. This article aims to provide wisdom, based on knowledge and experience, for training in the off-season.

Coach & Mrs. Slezak's Home Gym

Coach & Mrs. Slezak’s Home Gym

Before we get into specifics we have to define what the off-season actually is. The off-season is a period of time when an athlete is not participating competitively in their sport. Team sports like football, basketball, and baseball have a clearly defined off-season. Other sports, such as tennis, have a much harder time defining one. And with the oftentimes overly intense youth sports industry, many young athletes jump from travel to all-star and then varsity high school teams hoping to get ahead and never actually have any off-season.

It is critical for all athletes, professional to youth, to have some sort of off-season built into the year. Playing sports at competitive maximums is taxing on the human body. It does not take much searching to find a sharp increase in overuse injuries for young athletes recently. High school pitchers having Tommy John’s elbow surgery, tennis players with wrist and rotator cuff issues, and knee/ankle problems from the stress of jumping and landing 100+ times on the basketball or volleyball court. It is common sense, you cannot race a car hard every single day at the track without something eventually breaking down and the human body is the same way.

If you cannot play your sport in the off-season then what can you do? First, I am not going to tell you that you cannot play your sport in the off-season. What I will tell you is that you should not be competing in your sport in the off-season. In fact, competing in your sport is the definition of being in-season. This downtime is an opportunity to perform technical skill work or practice but at a much lower intensity and volume then during your competitive season. For example, this would be the time a basketball player could improve dribbling skills or a tennis player technical stroke work. The key take away here is you are not playing your sport at competitive max or “racing speed.”

The off-season is also the time to improve foundational movement patterns, general strength and conditioning. In fact, this should be the bulk of the work done in the off-season. This work done in the off-season builds the base for the future. Improving fundamental movement patterns like squatting, hinging at the hip, pushing, and pulling all improve overall athleticism. The conditioning work done to the aerobic system in the off-season provides the base for the higher-intensity demands to come in the pre and competitive seasons. The improvement of general strength will allow for the athlete to sprint faster, jump higher, and throw harder during the competitive season. You simply cannot build these qualities in the middle of a competitive season. You must build these qualities in the off-season so they can be expressed during the competitive season.

Each sport and athlete has specific needs and if you are serious about getting the most out of the off-season time I would hire a knowledgeable and experienced trainer. The gold-standard for anyone working with youth is to be certified by the International Youth Conditioning Association (IYCA) but the bottom line is do your homework and find someone who thinks long-term and has your best interest in mind. With that being said in a 6-8 week off-season 3 of the most common goals are to develop the aerobic energy system, improve general strength, and clean up fundamental movement patterns.

Regardless of the sport a well-conditioned aerobic system is essential. Obviously a well-conditioned aerobic system will benefit someone like a distance runner or soccer player. However, what most people do not understand is that a fine-tuned aerobic system provides benefits in almost all sports. This is because the aerobic system (energy with oxygen) is responsible for replenishing the fuel for the anaerobic energy system (energy without oxygen). That means football and tennis players need their aerobic system to replenish the anaerobic systems that allow them to perform bursts of high-intensity performance intervals. This is a tremendous advantage late in the game during the competitive season and it can only be accomplished by doing some work dedicated to improving the ability of the lungs, heart and circulatory system to deliver oxygen to working muscle.

Anyone Serious About Training Needs a Heart Rate Monitor

Anyone Serious About Training Needs a Heart Rate Monitor

Another benefit of aerobic training in the off-season, which would include long runs, swimming, or biking at a heart rate of 130-150 beats per minute, is that it promotes recovery. Delivering oxygen rich blood throughout the body aids in rebuilding tissues that take a beating during the competitive season. In addition, it is relatively easy on the nervous system. The nervous system takes a beating during the competitive season with all the quick movements and maximal muscle contractions and aerobic training gives it time to de-load and recover.

The off-season is also the time to lift heavy things and put on some muscle mass. The force a muscle is able to produce is directly related to its cross-sectional size. If you want to be able to run, jump, and throw harder next season then strength training is essential. Strength training simply means you are going to stress the muscle by lifting something heavy and your body will respond by making it bigger and stronger. An athlete does not have to go to the weight room or have access to fancy equipment to strength train. In fact, for most youth athletes bodyweight is the best place to start. After all if you cannot move your own body weight appropriately adding 50lbs on top of your back is asking for an injury.

When strength training the focus should be on movement patterns not on specific muscles. For example, you want to improve strength in fundamental movement patterns such as squatting, hip hinging, pushing, pulling, and core stability. This is easily done with body weight, free weights, sandbags, and resistance bands. It is not easily done with the machines you find in most gyms that isolate specific muscles and joints.

Building a solid foundation of strength in the off-season is then followed up with learning how to expressing that new found strength during the pre-season and then fully in the competitive season. The key here is to understand that to focus on improving general strength in the off-season and then working during the pre and competitive season to apply it.

Figure 1 - Pyramid of Athletic Development

Figure 1 – Pyramid of Athletic Development

The final objective of the off-season is to clean up fundamental movement patterns. This is the time to make sure you can squat fully, hip hinge correctly, and have good posture. This aspect of training is becoming even more important in today’s society. Think about the amount of time children spend sitting on the computer, texting on their phone, and sitting in classrooms. It is causing an epidemic of bad posture and moving in those compromised positions or even worse training and competing in them is a major contributing factor to youth sports injuries such as spondylolysis (stress fracture in the lower back) and shoulder injuries. It is common sense, when you spend all day hunched over and your lower back is in excessive curvature you develop poor posture as your default. Look at the pyramid of athletic development (figure 1) and it is clear to see the base for all of sport is movement. You cannot layer fitness and sports skills on top of dysfunctional movement without eventually paying the price.

It is impossible to prescribe a general workout for the off-season because the needs of each athlete and sport are unique. Some athletes may need to spend more time on developing strength and others improving conditioning. However, below is a very general yet insightful look at the typical week of training in the off-season. Planning training or periodization is a science in and of itself, but one of the biggest things to notice below is how the training is spaced out. An athlete cannot work hard 3 or 4 days in a row and then take 3 or 4 days off. Training is nothing more than applying stress to the body. The body then adapts to the stresses placed on it during rest and recovery. The real physical changes happen between workouts, not during them. Understanding the importance of rest and proper nutrition between workouts will maximize success and allow you to train both hard and smart.

Sample Week of Off-Season Training

Sample Week of Off-Season Training

If you look at everything I presented about off-season training and put it in the context of the bigger picture it becomes clear how important it is when thinking long-term. If you understand that, then I will let you in on a little secret about developing champion athletes. Most parents and coaches are only concerned with the short-term. They want to win the big game next week, the tournament this weekend, or make the U12 all-star soccer team. They may achieve those things but they take shortcuts to get them, such as skipping the off-season. Those shortcuts eventually catch up. On the other hand the true champion athletes are focused on the long-term from the very beginning and they never take shortcuts. They do the work in the off-season and over the course of years develop outstanding conditioning, strength, and stay injury free. They also are the ones who may have missed out on winning the championship in 7th grade but eventually end up with scholarship offers and notable accomplishments when it counts.

To conclude, I hope this article sheds some light on just how important off-season training really is to in-season performance. If you pay the price of time and sweat during the off-season you certainly will reap the benefits during the heat of the battle in-season.

The Strength Deficit as it Relates to Tennis

WeddingMy wife and I workout together in our cozy little home basement gym.  She has been crushing it for some time now and getting strong!  She normally doesn’t ask too many questions and just does what I program for her.  And I do have a method for programming workouts that involves what I am about to tell you about.

However, the other day she decided to do one of those follow-along video workouts. There was a lot of plyometric jumps involved which sparked some conversation over dinner about a little known concept called the Strength Deficit.  I am going to simplify the concept for you and if you are a tennis player it is absolutely critical to maximizing performance through off court training.

There are two kinds of strength you need to understand before we can move on to defining the strength deficit.

The first type is Absolute Strength.  This kind of strength is the absolute maximum amount of contractile force a muscle is capable of producing involuntarily.  In a laboratory setting we could stimulate your nerves with an electrical impulse causing the muscle fibers to contract.  In doing this experiment one could theoretically measure the absolute maximum contractile force your muscles are capable of producing.  Absolute strength is closely related to the size of the muscle fibers.  In other words, the larger the muscle is the greater the absolute strength potential.

The second type of strength is the Competitive Maximum.  This is the maximum amount of contractile force a muscle can produce voluntarily.  In other words this is the force you are capable of creating under your own control.  The competitive maximum is related directly to your central nervous system (CNS).  The stronger the impulse your can send through your nerves to the muscle fibers the more forcefully you can get them to contract.

So now that you understand that the absolute maximum is involuntary and the competitive maximum is voluntary we can get to the Strength Deficit.  The strength deficit is simply the difference between the two.  It should be noted that the absolute strength will always be higher than the competitive maximum because you will always be able to involuntarily contract muscle fibers to produce more strength compared to what you can do voluntarily.

Strength Deficit

What the strength deficit tells an athlete about their current state is amazingly insightful.  And if you know how to interpret the information it gives you a roadmap for how to continue making strength gains.

Here is how to interpret the strength deficit…

If the competitive maximum is close to the absolute strength you have a small strength deficit. A small deficit means that an athlete is able to send strong messages to the muscles and stimulate a strong contraction.  This is a very good sign because it means they are capable of utilizing most of their capacity for strength.  If an athlete with a small strength deficit wants to improve they need to focus their efforts on muscle hypertrophy or growth in order to raise the level of absolute strength.

If the competitive maximum is further from absolute strength you have a large strength deficit.  This means the potential for strength is there but the CNS is not capable of creating a strong enough signal to excite the muscle fibers to utilize it.  This tells an athlete they have room for strength gains without putting on more muscle.  Gains can be made by specifically designing explosive training sessions to stimulate CNS development.  Focusing on gaining more muscle mass will only increase absolute strength and the strength deficit further.

Now before I go any further the strength deficit is a fairly advanced concept and I do not want you running out and applying this to kids or beginners.  You really need to know what you are doing and this is just a overly simple blog post explaining the bigger concept.  If you want more information I recommend reading a highly complex book translated from the work of Russian Sport Scientist Yuri Verkhoshansky, Super Training.  With that being said if you are just getting started lifting weights you will see improvements in both absolute strength and competitive maximums quickly.  Beginners just have more room to make adaptations and improve.  However, if you are hitting plateaus, it is a good idea to look at your strength deficit and see if you should focus your efforts on gaining more muscle size and absolute strength potential or finding ways to stimulate the CNS and its ability to maximize muscle fiber contractibility.

Now think about a competitive tennis player’s needs…

First, tennis players need explosive and powerful muscle contractions.  They need to swing the racket with amazing accelerations and speed.  Players need to be able to sprint, change directions, and reaccelerate again.  These skills require a great deal of power without having an enormous body building style muscular frame that can slow an athlete down.  By now you should be able to guess that tennis players should have a small strength deficit.  Tennis players want to be able to maximally contract the muscle fibers they have.  That is not to say that there is never a time to build bulk and absolute strength because there is.  However, once muscle hypertrophy or mass is gained it should be followed up with a block of training to stimulate the CNS to utilize that new found strength potential fully.  Players like Djokovic, Nadal, and Federer are incredibly strong and I would bet they also have a small strength deficit.

Questions or comments leave them below and I will be happy to answer them.

Strength Training for Coordination

Strength training has been around for a while and most people think its all about pumping iron to get bigger muscles.  Makes sense for football players but not always so for tennis players.  In fact, tennis players mistakenly fail to strength train for two main reasons, either they think because tennis is so skill-specific lifting is a waste of time and/or they are afraid to get big and bulky.  The truth is strength training is extremely beneficial to sports like tennis with high coordination demands.  That means a tennis player can actually benefit more from strength training than a football player.  It also does not mean you’ll look like a body builder either.

Let me explain why and in the process you’ll learn a secret about how strength training really works to improve performance…

Your central nervous system (CNS), brain and spinal cord, controls your muscles.  Understand that your skeletal muscles are not very smart they simply do as they are told and turn on or contract when the CNS tells them to.  Your muscles are made up of tons of individual fibers called slow and fast twitch respectively.  The slow twitch are the endurance fibers and the fast twitch are the power fibers.  Now here is something not so well known.  What people do not understand is the CNS does not activate all the fibers in a muscle at once.  It is not all or none activation which is good or we wouldn’t be able to use fine motor skills to write with a pencil very effectively.  For example, when you walk the CNS only contracts 10% of the muscle fibers at once and your CNS cycles through different fibers to avoid fatigue.  When you jog your CNS contracts about 30% of the muscle fibers.  Do something like working up to lifting a maximum weight and you are using around 50% of your muscle fibers.  You see you brain is smart and never fully activates 100% of the muscle fibers because it could lead to some serious trouble liking running out of ATP but that is a little deep in science for this post.

While you were thinking through the above example you were probably imagining just activating one muscle but the truth is no movement activates just one muscle, it is coordinated symphony of contraction, stabilization, and relaxation of all the muscles in your body.  Just like hitting a forehand.  The coordination necessary is truly amazing if you take a moment to think about it!

So why would strength training benefit a skill-based sport like tennis so much, because it develops coordination.  Strength training is a workout for the CNS as much as it is for the muscles.  The CNS gets better at coordinating contractions, developing the neural network to muscle fibers, and becoming more and more efficient.  In fact, when someone first starts strength training they’ll see gains in performance very quickly.  Those initial gains are directly related to the CNS because it is able to more effectively and efficiently coordinate the muscular contractions necessary to meet the demands.

On a side note this is also related to why elderly people are more likely to fall and have balance issues. Think how a young person catches their toe and regains balance while an elderly person cannot.  Its not so much that the muscles are deteriorating, it is because the neural connections between the brain and the muscles are deteriorating due to lack of use.  So strength training is not just for athletes, it can benefit everyone!

So the bottom line is one of the biggest bangs for your buck in improving at tennis or any athletic endeavor is strength training.  It will improve coordination which leads to improved athletic performances.  It is the mind-body connection in every sense.