The Effect of Lactic Acid on Endurance and On-Court Performance

How iTUSA measures and monitors a player's lactic acid production to customize an endurance program for maximum results.

Click here to watch a video showing the process in detail.  
iTUSA believes that players must not only incorporate physical training into their tennis development programs, but they must also incorporate training with the appropriate intervals and intensity, based on each individual's performance and muscular endurance level.

In today's tennis game, fitness has become one of the most underrated, yet crucial aspects of the sport. Much emphasis has been placed on strength training and weightlifting, versus muscular endurance conditioning. For years Spanish tennis and soccer players have been developing their muscular endurance and winning championships. It is time to start equipping yourselves and your players with the knowledge of why players become fatigued mentally and physically and how to improve their endurance. To become a mentally tough competitor you must achieve the highest levels of endurance, so you can last physically and mentally while maintaining your maximum intensity throughout an entire match, no matter the level of play.  

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Over time VO2max testing has become popular in many sports, measuring an athlete's maximum heart rate; however, the VO2max test is not specific to all sports, including tennis and only provides training guidelines based on a an athlete's heart rate. iTUSA uses its endurance and lactic acid technology to measure not only a player's heart rate, but also the amount of lactic acid in the player's bloodstream by testing their performance at varying degrees of physical activity and training.

Muscular endurance is defined as a player's ability to perform a high volume of sub-maximal efforts without becoming fatigued. The longer in length and the higher number of repetitions a player can perform at this sub-maximal level, the greater the player's muscular endurance level. So what causes a player's muscular endurance to break down? The answer - lactic acid buildup in the bloodstream.

When players train, their bodies and muscles are continually producing and using oxygen. The harder a player trains, the more oxygen their blood uses in order to keep up with the intense activity. As training becomes more intense, the body reaches a state at which it cannot keep up with the demand for oxygen and begins to produce lactic acid. It is at this point where your muscles turn to anaerobic energy production, a state where the body no longer uses oxygen for energy production. The result of this process produces heat and lactic acid. The body is then unable to remove more lactic acid from a player's bloodstream than the player's cells are producing, and lactic acid begins to accumulate. The increased amount of lactic acid in the bloodstream increases the pH level of the player’s blood, in return causing training or competing to become fatiguing.

Since 2002 and thanks to Dr. Bram Van Dam, who headed the physical/medical department of iTUSA, we have incorporated the most advanced endurance and lactic acid technology. Coaches and players can monitor their lactic acid levels and use high-intensity training to manipulate the players’ ability to adapt to the stress of the increased physical activity. With this knowledge coaches and players can specifically train to perform high intensity exercises for a longer period of time, which will adapt their body's ability to clear more lactic acid from their bloodstream.

Unfortunately Dr. Bram Van Dam passed away in 2009, but he left at iTUSA a legacy that will always continue. We attribute a lot of the success of our pro clients to his knowledge and methodology. He was a master of teaching our players how to achieve the maximum levels of performance through proper training, nutrition and dietary supplementation, which should be always integrated into the daily regimen of a player.

As a coach it is your duty to ensure your players are performing at their highest level day in and day out. Equipped with the science and knowledge of knowing how long your player can perform at peak performance before they begin to break down, will allow you to maximize your daily training with each individual player. As you being to understand your players’ physical muscular endurance level based on lactic acid testing, you will be able to develop specific training programs for each player to maximize their endurance and resistance to lactic acid build up, thus improving their overall muscle endurance and conditioning levels. Not only will this improve your players’ ability to perform at a higher level for longer on the court, but it will also provide them with the advantage of knowing it is only a matter of time before their opponents break down physically and then mentally. We have all seen it thousands of times when a player misses an easy shot due to physical fatigue and then little by little their confidence and mental sharpness begins to fade.

In order to test for a players lactic acid there are three main steps:

  1. Apply heart rate monitor to your player and measure their resting heart rate

    1. This will give you a basis for your testing.
  2. Ball machine set up

    1. Interval
      • In order to do this you will need to know how many balls per minute each setting on your machine will produce.
      • There are 5 levels/speeds on the ball machine that you will use for the lactic acid test.
      • Settings - Settings can go from beginner all the way up to professional level of play
        •     12 balls/minute - Lowest intensity
        •     15 balls/minute
        •     17.5 balls/minute
        •     20 balls/minute
        •     24 balls/minute - Highest intensity
    2. Location
      • You will want to set the ball machine so that it is going to move the player from sideline to sideline. Ideally you will want the ball to be roughly 3 feet between the baseline and sideline on each side of the court.
    3. Length of Time
      • Have each player return balls for three continuous minutes starting with the lowest intensity and increasing by one intensity level after each lactic acid reading until the player’s lactic acid level is 4.0 or higher.
  3. Lactic Acid Test

    1. After each round, record the player’s heart rate and the player’s level of lactic acid.
    2. A reading of 0.8 is the lowest readable level of lactic acid.
    3. Increase the intensity and repeat until the players lactic acid level has reached 4.0 or higher. A lactic acid reading of 4.0 is considered the highest allowable level of lactic acid in the bloodstream for them to perform at peak performance.
Below is an example of the improvement in a player’s ability to remove and process lactic acid out of the bloodstream, with just four weeks of intense endurance training.

You can see the difference in the player’s muscle endurance, and the ability to clear lactic acid from the bloodstream has improved significantly in the period of just one month. In July the player’s lactic acid reading during the second interval training came in at over 4.0, while in the month of August it was not until the 4th interval that the player’s lactic acid reading surpassed 4.0. With this knowledge it is easy to see how coaches can train their players appropriately to improve their endurance and increase their chances of success on the court. Coaches can now develop and implement training programs and drills specific to each individual player with the science to back up the programs. The ability to evaluate the direct correlation between heart rate and lactic acid allows coaches to get the most out of their players and push them to new limits, while still keeping them fresh, and most importantly, healthy and safe.

Internships Available at the iTUSA Academy in Scottsdale, Arizona, USA

Internships are being offered for U.S. and international coaches who want to learn the ins and outs of developing juniors into professional players, as well as how to maximize today's technology to achieve world-class performance for players of all levels and ages.

Apply for full scholarships which cover your training, Level 3 Coaches Certification, airfare, and full room and board expenses for the duration of your stay. Send your resume and cover letter explaining how you will utilize this program to

Coaches will receive iTUSA level 3 training and certification.

The iTUSA Coaches Certification Program is a certification program that trains you in the secrets of the iTUSA system—a system that turns players into champions! The training will take place at the iTUSA Training Center in Scottsdale, Arizona. The key benefits of the iTUSA Coaches Certification Program are:
    • Better results
    • More recognition
    • Higher income

The certification program covers the following curriculum:
    • Player Skills Assessment
    • Player Fitness Assessment
    • Player Developmental Planning
    • Skills Training Paths for Beginning, Intermediate, Advanced, and World-Class Players
    • Fitness Training Paths for Beginning, Intermediate, Advanced, and World-Class Players
    • Training in iTUSA Online Coaching and Instructional Tools
        o Training Drills Database
        o Match Analysis
        o Stroke Analysis
    • Business Development

The iTUSA System

Rather than forcing a player to conform to a rigid system, the iTUSA Development System is built around each player's individual abilities. No system taught the greatest innovations in the modern game, from Laver's topspin on both wings, to Borg's whipping groundstrokes, to Agassi's uncanny ability to hit balls on the rise. The players led the way—and then the coaches built a system around it. Here at iTUSA, we begin with the recognition that the game of tennis is constantly evolving and players emerge with new skills and new ways to win. We build on the cutting-edge of those innovations. We also respect and recognize the unique abilities of each athlete and then adapt our training disciplines around those abilities. Taking each individual's game, the iTUSA system develops the footwork, stroke mechanics, tactics and mental toughness the player needs to achieve his/her goals. Bottom line, our system produces great results! Every player enrolled in our World Class Tennis system has received either a full tennis scholarship to a university or become a professional tennis player!

iTUSA Congratulates British Player Scott Clayton for Winning His First ITF Junior Title!

Last October, Scott traveled to his first ITF events as part of iTUSA's ITF Traveling Team to try to qualify for the ITF events of South Carolina and Atlanta. In less than a year playing on the ITF World Junior Tour, Scott has captured his first title by winning the X Sanxenso International title, a Grade 4 event in Spain.

Scott defeated Henrique Sousa from Portugal 6-4, 6-2 in the finals. Prior to his final match, Scott defeated 4 Spanish players along the way. Scott defeated top seed Enrique Bautista in the quarterfinals. Scott will be participating in Cyprus this week.

Everybody at iTUSA is proud of Scott's success and knows this is just the beginning of many more titles to come. Mr. Murray, beware that Scott "Lleyton Bazooka" Clayton is on his way to lead British tennis to new heights.

Getting to Know iTUSA’s Players

Periodically, we will be including in our newsletter a bio and/or video allowing you to get to know one of iTUSA’s players. As you know, iTUSA is very selective as to the students accepted to attend our academy, and this provides a way for us to showcase these exceptional athletes. This month we feature Bojan Temunovic. Click here to watch his video introduction.

iTUSA Wants YOUR Input

Some of you may be reading our newsletter for the first time. Many of you have been reading the newsletter since we first started producing it last year. No matter how long you’ve been reading it, we’d like your feedback.

Which sections do you like/dislike most? Do you enjoy the updates about Arnaud, the current student in iTUSA’s Africa Foundation program? Do you prefer our latest Tennis Psychology articles with Dr. Allen Fox, did you like the former articles with Dr. Robert Soloway, or is a variety of perspectives best? Should articles be shorter or more in-depth? Would you like to see more videos supporting the articles? Should we include more information about iTUSA’s products and services? What other topics would you like to see us cover?

These are just a few examples of the type of information we’d like to hear from you. Please feel free to answer the specific questions above or share anything that’s on your mind. Click here to access our contact page to give iTUSA your feedback now.


Arnaud Welcomes New Players From Every Corner of the World to the Academy

Andy Romero from Mexico, Joaquin de Leon from Spain, and Supriya Narisetti from North Carolina join iTUSA's World Class Academy, where an exclusive group of selected junior players pursue their dreams to become championship-caliber professional players.

These 3 players now complete the roster of iTUSA's elite junior team. Andy, Joaquin, and Supriya will be preparing to participate in international events and hopefully join iTUSA’s ITF, ATP, and WTA traveling teams, to further develop their skills and advance their careers. iTUSA's Academy enrollment is by selection only and is limited to a reduced group of talented and dedicated players who are committed to reach their full potential.

The three newcomers are just part of the historic continued success of the iTUSA program. We are very proud of all of our players, past and present. It is no coincidence that over the last 20 years every iTUSA graduate has either received a full scholarship to a major university or college or gone on to pursue their career at the professional level. With the overall methodology of iTUSA and the individualized and specific training programs developed for players, their true maximum potential is not only realized, but also achieved.

Click here to view a special video and to learn how you can help the Foundation.

Read the background of Arnaud’s story from our October 2010 newsletter here.

Developing Proper Muscle Memory in your Backhand (Using a Resistance Cord), by Jofre Porta

Objective: This exercise will help you develop strength and good fundamentals for your backhand. By performing this drill correctly, you will develop a sound coiling motion while you strengthen not only your core and arms, but also your entire body, while giving you the leg stability you need to hit a solid backhand.

Description: Place a resistance cord in the back fence of the court and tie the other end around the tip of your racquet. Move forward so the cord is tight, but to the point that you are still comfortable to swing the racquet with relative ease. The farther forward you move, the difficulty of each swing will increase.

This is a wonderful drill no matter if you hit a one-handed or two-handed backhand. The main focus of this drill is in the distance that the racquet travels to the point of contact. This part of the swing requires the most stability and proper technique.

Your body should "screw down" into the court, with your knees bent, rotating the hips and coiling the entire body. The legs are activated with the initial turn of the hips; then transfer your momentum into the court as you swing forward and keep your head still throughout the entire motion.

For the one-handed backhand, move your non-hitting arm toward the back fence to enhance a solid center of balance by countering the racquet arm.

Another benefit that you will incorporate into your backhand with this drill is a much more solid point of contact. The faster the ball comes at you, the more important the solid contact becomes.

The second part of the drill is to take the racquet from the point of contact backward to the starting position of the backhand IN SLOW MOTION. This will train your muscle memory and every part of your body, including your brain to perform the proper motion and stability in sync.

Shadow tennis and slowing down your motion is a very effective way of learning and retraining new mechanics and techniques. You can do it as a warm up, cool down or in between practice shots. It is a great mental exercise to practice the correct shadow swings after making a technical mistake.

With the addition of the resistance cord, we believe your training session will include variety, a great element of explosiveness, and better fundamentals not only in your strokes but also in your footwork.

The drills in the upcoming newsletters will help you incorporate the resistance cord into all the components of your training sessions. October's newsletter will focus on your forward and backward footwork followed up by November, when we will show you how to integrate technique and footwork together with the proper use of the resistance cord.

Jofre Porta has already had a remarkably successful coaching career. He is the man who coached Carlos Moya from the juniors to becoming the French Open Champion in 1998, all the way to helping Moya become the #1 player in the world in 1999. Jofre also played a critical role in coaching Rafael Nadal in his formative years (between the ages 8 to 17). Jofre was in charge of helping Nadal getting established on the right foot as a professional.

Click here to watch the drill.

More Drills in iTUSA's Training Drills Database

Each week 9 new drills are added to the database!

Please visit this link to view iTUSA's Training Drills Database with over 1,000 training drills:


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Your Game Will Follow Your Emotions, by Allen Fox, Ph.D.

About Dr. Allen Fox

Dr. Allen Fox earned a Ph.D. in psychology at UCLA and is a former NCAA champion, Wimbledon quarterfinalist, a three-time member of the U.S. Davis Cup team, and coached the Pepperdine tennis team to two NCAA finals. He currently consults with tennis players on mental issues, appears in his popular 1-Minute Clinics on the Tennis Channel, and lectures world-wide on sports psychology. He is also an editor and writer for Tennis Magazine.

Dr. Fox is the author of four books: “IF I’M THE BETTER PLAYER, WHY CAN’T I WIN?”, “THINK TO WIN,” “THE WINNER’S MIND, a Competitor’s Guide to Sports and Business Success,” and “TENNIS: WINNING THE MENTAL MATCH.”

His books can be purchased on his website at  

By Allen Fox, Ph.D. © 2010, all rights reserved

When you feel good, you are apt to play well; conversely, when you feel bad, you are likely to play poorly. Sport psychologists talk about the need to control emotion on court, but what they mean by this is not simply suppressing emotions (like anger or depression). They refer instead to an optimum strategy by which players not only rid themselves of negative emotions but also to create positive ones.

As an example of the power of emotion to affect athletic performance, consider the issue of home court advantage, which is mostly an emotional advantage. In the major professional sports leagues the home teams had the following winning percentages: baseball – 53% (1991-2002), hockey – 55% (1998-2003), football – 58% (2001-2005), and basketball – 61% (2001-2006). Many explanations have been offered including variations in days of rest, sleep, travel-fatigue, etc. but the most important factors seem to be largely emotional - familiarity with the playing field or court and the influence of the crowd. This is supported by noting that in the NBA the winning percentages for the home teams are usually greatest in the playoffs, where the crowds are larger and louder than they are during the regular season. These effects are obviously mostly psychological, since the size of the court, the height of the basket, and the bounce of the ball are the same as they were during the regular season, and are basically the same from arena to arena. The screaming support of the home fans affects the players’ emotions and helps the home team play better and the visitors play worse.

During tennis competition, as with the other sports, positive emotions help but do not guarantee good play. This fact tends to confuse players, because they often find that they still lose matches even after disciplining their emotions positively and well. So they start to think emotional control has no value. And they are dead wrong! Even though good emotions do not ever guarantee a victory, bad emotions often guarantee a loss. Emotions only set the stage for the quality of play that follows, but they don’t control it. Good emotions only make good play more likely; they don’t guarantee anything. Finally, emotional effects on tennis performance are often overlooked because they may be small, sometimes only a difference of a point or two here and there, which are hardly noticeable. (But these few points, in a close match, often make the difference between winning and losing.)

Habits, repetitions, and our strokes: Our strokes are controlled by sequences of muscle memories that are programmed into the nervous system through repetition in practice. The more correct repetitions, the more accurate the programming and the more likely the stroke is to function properly in competition. Optimal tactical responses to an opponent’s shots during play are also programmed into our nervous systems by reward and punishment during past competition. For example, when we hit the right shot and win the point and, in the same situation, hit the wrong shot and lose the point, our nervous systems record this information and use it later to improve shot selection. Eventually the strokes and immediate tactical responses are no longer under conscious control in matches. They function by habit and come out too quickly for conscious thought. Of course at the conscious level we need to have game plans and remain sensitive to how well they are working in order to make effective adjustments, but this is all superimposed upon the set of basic programmed habits and responses that function below the level of conscious thought.

Now for the punch line: these habits and programmed responses are substantially affected by strong emotion. They are disrupted by negative emotions (and negative thought processes that ultimately produce negative emotions) like anger, depression, fear, and pessimism. On the other hand, they are helped by positive emotions (and positive thought processes that ultimately produce positive emotions) like optimism, controlled aggression, feelings of confidence, strength and courage, and optimal levels of arousal. Even when the effects are small they often make the difference between victory and defeat.

Don’t let your emotions be controlled by what is happening on court. In competition, the top pros spend most of their time between points striving to eliminate negative emotions and create positive ones. This requires an emotional plan and the discipline to implement it regardless of negative events that may occur during match play. The less successful players allow their emotions to be determined by what is happening on court. This is an unstable and circular situation in that their emotions are controlled by events (which are out of their control) rather than by themselves. Here bad play produces bad emotions which in turn produce further bad play. The trick in maximizing performance and reducing its variability is for the player to produce positive emotions before every point, independent of what is happening on court.

Although a detailed treatise on creating positive emotions is beyond the scope of this chapter, the essence of the process is that you begin by having no emotion at all at the end of a point. (Don’t allow anything that happens on court to shake you in any way.) Then, starting from an emotionally neutral position, you consciously and deliberately (through visualization, positive interpretation of events on court, self-exhortation, etc.) work to conjure up positive emotions before the next point starts. This will set the stage properly and increase your odds of playing well when the next point begins.


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