In recent years resistance training for tennis players has become more common. In the past resistance training may have been avoided by tennis players and coaches for a variety of reasons, including a fear of getting too muscular, decreasing flexibility, and limited time between on-court practice or tournaments. If a resistance training program is planned properly, these problems can be avoided. Significant increases in muscle mass will not be a goal of resistance training programs specifically designed for tennis. When resistance training is performed properly through a sport-specific range of motion combined with a proper flexibility program, there will be no decrease in flexibility, and if performed correctly, should actually increase functional flexibility. Resistance training for elite players can be difficult to plan because they can play in tournaments nearly every week. The concept of periodization is therefore an important component for integrating resistance training into an overall program for maximizing performance and allowing recovery for major tournaments. Periodization will be discussed further in Chapter 15.
With the increased power and speed in today’s game, resistance training is a vital component to compete at an elite level. Today, tennis players are bigger, stronger, more powerful, and faster than before, and they are hitting the ball harder than ever before. There are two major functions of a resistance training program for tennis players. The first function is to improve maximal force and power outputs. Because of the pace of today’s game, maximal power is critical to success. The second function of resistance training is to decrease the risk of injuries. There is no real off-season in tennis, and many players will play too many tournaments with too little rest and experience injuries as a result. A well-planned resistance training program designed to decrease injury risk is also critical to the success of a tennis player.
In response to a resistance training program, various adaptations to the body will occur. Resistance training enhances both absolute and relative muscular strength (6). Absolute muscular strength refers to the maximal strength an individual can develop regardless of their body weight. Relative muscular strength is dependent on a person’s body weight. It is calculated by dividing a person’s absolute muscular strength by his/her body weight. Males generally have a greater absolute muscular strength than females due to their increased muscle mass. When relative muscular strength is considered, there is little difference between males and females (2).
Increased muscular strength is one of the main benefits of resistance training. These increases are generally due to both neural factors and muscle hypertrophy. The greatest strength increases are seen in the early weeks of training and are primarily due to neural factors (24). These can be divided into intermuscular and intramuscular adaptations. Intramuscular adaptations include the increasing of both the number of motor units that can be recruited at once and the activation rate of those motor units (6). These two factors combine to produce greater force than can be accomplished without resistance training.
Intermuscular adaptations refer to the improved coordination of muscle firing patterns. As exercise technique improves, muscles will work more efficiently and less energy is required to perform the exercise and the resistance can be increased (13). Increased force production and coordination are the main reasons for the initial strength increases seen in previously untrained individuals. These neural factors are what contribute to an athlete’s increase in strength over the first 5-8 weeks of training without having any noticeable changes in muscle size.
Another factor related to increased muscular strength as a result of resistance training is hypertrophy (23, 31). Hypertrophy is the enlargement of the diameter of the individual muscle fiber. Muscle hypertrophy does not become apparent until weeks 5-8 of training (27). Hypertrophy is caused by progressive overload, proper muscle recruitment, and adequate energy intake (9). Another theory for the increased cross-sectional area seen in muscle fibers with resistance training is hyperplasia. Hyperplasia refers to the splitting of the muscle into additional muscle fibers. Scientific evidence suggests this likely does not occur in humans (22).
The force a muscle is capable of producing is strongly related to its cross-sectional area. Muscles with a larger cross-sectional area are able to produce greater force. When muscles are properly loaded they adapt to this stress by synthesizing more protein, specifically actin and myosin. Actin and myosin are referred to as “contractile proteins” as they are the structures within muscle that attach and develop tension during muscle contraction. This increase in contractile proteins causes the increases in cross-sectional area in muscle tissue. Greatest gains in hypertrophy are seen most with intensities between 60 and 80 percent of the maximum amount of weight which can be lifted one time (1RM) and a higher volume of training (19).
Another adaptation to resistance training is increased bone density (26). Increased bone density will reduce the risk of injury due to a fracture. Adaptation occurs by increasing mineralization in the area of stress. Multi-joint weight bearing exercises such as squats and lunges are most beneficial in improving bone mineral density (26).
Other adaptations to resistance training are dependent on the type of training which takes place. High-intensity resistance training can promote significant increases in muscle glycogen, creatine phosphate, ATP (energy), and glycolytic enzymes stores (16). These changes will increase the ability of the muscle to repeatedly produce power over a period of time. Low-intensity, high-volume training may improve a muscle’s endurance capacity (16). Muscular endurance is important for tennis players to prepare them for long matches.
Three main fiber types have been identified and studied in humans. These fibers are Type I, Type IIa, and Type IIx. Type I fibers, also referred to as slow oxidative, have a slow contraction time and are highly resistant to fatigue. They are used predominantly in low intensity, long duration activities which require oxidative pathways to produce ATP. They produce low amounts of force and velocity and are most often found in muscles which provide posture and support. Due to their aerobic nature these fibers have many mitochondria and are rich in myoglobin, which produces their red color.
Type IIa fibers, or fast-oxidative, are intermediate fibers with moderate resistance to fatigue and contraction time. Type IIx fibers, or fast-glycolytic fibers, contract very quickly and fatigue very rapidly. They are very powerful and are used predominantly in activities which require a short burst of energy over a very short period of time. Fast-twitch muscle fibers typically increase in cross-sectional area more than slow-twitch fibers as a result of resistance training (1, 23). As the speed of the game has increased, power output from the fast twitch muscle fibers has become an important factor in improving performance. In addition to increasing the size of the fast twitch muscle fibers, nervous system adaptations occur with ballistic training that facilitate the recruitment of fast twitch muscle fibers.
There are various types of contractions which are seen in human movement. Isotonic contractions involve a constant resistance throughout the movement. Isotonic resistance training is dynamic requiring active joint movement as well as shortening and lengthening of the muscle fibers. During isotonic resistance training two types of muscle actions occur—concentric and eccentric. Concentric actions occur when muscle fibers contract and shorten. An example of a concentric muscle action is the “upward” portion of a biceps curl. When the weight is raised upward, the biceps are shortening and a concentric action occurs. Eccentric actions occur when the muscle fibers lengthen. An example of an eccentric action can be seen in the downward motion of a biceps curl. As the weight is lowered the muscles lengthen and an eccentric action occurs. Isotonic resistance training is used most often by tennis players as it is more specific to the sport compared to other types of training. Except for gripping the tennis racquet, muscle actions in tennis involve dynamic movement with a fixed resistance.
Isometric strength training, on the other hand, involves maximal force exerted against an immovable object. There is no joint movement and the muscle fibers do not shorten or lengthen. Trying to move an object which is too heavy to move is an example of an isometric contraction. Isometric strength training is used very rarely by tennis players as it is not specific to the sport.
Isokinetic training generally involves specialized equipment that varies the resistance. Isokinetic training requires a constant velocity of movement with a variable resistance. Through a range of motion, isokinetic equipment attempts to keep the speed of joint movement constant by varying the resistance. This form of training requires specialized equipment and is not practical for most tennis players. Additionally, an isokinetic muscle action is not specific to the sport.
The first step in designing a resistance training program is to perform a needs analysis of the activity and the athlete. In order to maximize performance the program must be specific to both the sport and the athlete. The major muscle groups used, the types of movements, the speed of movements, and the common sites of injury should all be taken into consideration. The athlete’s physical strengths, weaknesses, and injury history should all be considered in a needs analysis (30).
An analysis of the muscle groups used in tennis should consider all the strokes and movement patterns.
Figure 7.1: Forehand muscles in action.
Push-off: Soleus, Gastrocnemius, Quadriceps, Gluteals
Trunk Rotation: Obliques, Spinal Erectors
Forehand Swing: Anterior Deltoid, Pectorals, Shoulder Internal Rotators, Biceps, Serratus Anterior
Figure 7.2: Backhand muscles in action.
Push-off: Soleus, Gastrocnemius, Quadriceps, Gluteals
Trunk Rotation: Obliques, Spinal Erectors
Backhand Swing: Rhomboids, Middle Trapezius, Posterior Deltoid, Middle Deltoid, Shoulder External Rotators, Triceps, Serratus Anterior
Nondominant Arm (2-handed Backhand Only): Pectorals, Anterior Deltoid, Shoulder Internal Rotators (29).
Tennis requires many lunging movements and a large amount of torso rotation. It is important to note that tennis is a ground-based sport. Force is generated against the ground by the lower body. This force is transferred to the trunk and eventually the upper extremity. Increasing the force with which the player can “push” into the ground will increase the force of a hit tennis ball.
As the resistance a muscle has to overcome increases, the velocity of movement decreases (Figure 7.3). Likewise, as resistance decreases the velocity of movement will increase. Tennis is played at the high-velocity, low-resistance end of this continuum. Hitting a serve, running to hit a wide forehand, and lunging for a volley all require explosive, high-velocity movements with a relatively light resistance. Therefore a majority of the training should take place on this end of the force/velocity continuum.
Figure 7.3: Force-velocity curve. Tennis is played at high velocity and low resistance.
The total volume of training can be determined by multiplying the number of sets by the number of reps by the weight lifted.
A repetition is a single execution of the exercise from beginning to end. A set is a group of repetitions which are followed by a rest period. Total volume of a training program has a strong influence on many of the effects of a resistance training program. The number of repetitions should be determined by the goals of the training session. Total volume of training is heavily dependent on the number of sets performed. Should a player do single or multiple sets? In terms of improving athletic performance, training with multiple sets will likely provide superior results to training with one set (28, 32). Single sets may be appropriate for beginners or for advanced athletes during a maintenance phase. Programs which use a high volume typically have a greater influence on body composition and endurance.
Intensity in a resistance training program refers to the amount of weight that is lifted. There is an inverse relationship between intensity and the number of repetitions performed. A common measure of intensity is the percentage of the individual’s one repetition maximum (1RM). A 1RM is simply the maximum amount of weight an athlete can lift one time. A 1RM load will require maximal recruitment of available motor units. As resistance decreases below the 1RM load, fewer motor units are required to perform the exercise. For maximum strength development higher percentages of 1RM should be used, and for development of muscular endurance lower percentages of 1RM should be used.
Frequency refers to how often resistance training sessions occur. The frequency a person should train depends on the goals of training as well as the experience of the athlete. Training sessions must occur frequently enough to produce physiological changes, but provide enough rest to allow complete recovery and decrease the risk of overtraining. Sessions that use multiple-joint exercises, heavy loads, and large muscle groups may require greater recovery time prior to the next session. If proper recovery time between training sessions is not given, tissue repair and energy repletion will not take place. A general recommendation is to train similar muscle groups two to three times per week. Tournament schedules have a large impact on the frequency of training. During a tournament the frequency of training may need to be reduced or completely eliminated, particularly if the tournament is perceived as important.
Prior to choosing exercises a needs analysis on the sport must be performed. According to the principle of specificity, the more similar a resistance training exercise is to tennis performance the greater the probability of transfer to the court (5, 32). There are numerous exercises that can be used to target similar muscle groups or movement patterns. These exercises may be interchangeable in a resistance training program in order to get variety and prevent boredom. The exercises still must meet the specific goals of the exercise session. When choosing an exercise, the specificity of the exercise to the sport, the goal of the training session, and the ability of the participant, should all be considered.
Options for varying exercises include changing the mode, the angle of the exercise, and utilizing both single-limb and double-limb movements. When choosing exercises the relationship between agonists and antagonists should be taken into consideration. The agonists are the prime movers of a movement and the antagonists are the opposing muscle group. Resistance training and sports-specific movements will cause significant adaptations to increase performance in the agonist muscle groups. However, as the agonist muscles become stronger, the antagonist muscles may become increasingly susceptible to injury. Therefore, both agonist and antagonist muscle groups should be trained to prevent muscle imbalances, and to minimize the risk of injury. This concept is particularly important for tennis players because of the predominant use of the muscles in the chest and front of the shoulder. Training the antagonist muscles in the upper back and shoulder is critical to avoid injury.
Tempo refers to the speed the weight is moved both in the concentric and eccentric portions of the lift. The tempo of an exercise will vary based on the specific goals of the activity. Tempo can be regulated by measuring the time under the load. The time under load can be divided into four parts—the concentric and eccentric actions and the pauses between these contractions. When prescribing training programs the desired time under load is generally given in the order of eccentric action, pause, concentric action, pause. An example of a time under load prescription is 3, 1, 2, 1. This would require the lifter to perform the eccentric action over a count of 3 seconds, pause one second, then perform the concentric action over a period of two seconds, then pause for another second, and repeat the cycle for the prescribed number of reps. Intentionally slow movement velocities have been shown to be less effective at increasing work, power output, volume (21, 25), and increasing the rate of strength gains (14) when compared to moderate and fast movement speeds. Resistance training for the purpose of developing pure strength will usually have a moderate tempo since it is not dependent on time. Training for power, which by definition is measured per unit of time, will use a faster tempo to mimic more sports-specific activities. Because tennis requires explosive powerful movements, much of the training will be performed at a faster tempo.
Rest is the amount of time allowed between sets. The amount of rest between sets is dependent on the goals of that session. In strength and power training, the rest period is longer so that ATP can be replenished. Following exhaustive anaerobic exercise it takes approximately three minutes for the ATP stores in the muscle to be 100% replenished (13). It is generally recommended that for maximal strength or power training, there be two to three minutes of rest between sets. If proper rest is not given, the muscles may not be sufficiently recovered and the exercise will not be as productive. When muscular endurance is the goal of the training session, less rest is required. Rest periods of a minute or less are often prescribed for this type of training.
Exercise order is the sequence of exercises performed in a training session. The sequence can have a significant affect on fatigue and performance during a training session (12). It is generally recommended that multi-joint exercises which use large muscle groups be performed early in the training session when fatigue is minimal (18). For example, squats should be performed prior to leg curls. It is also recommended that exercises which require explosive power be performed prior to exercises which are aimed at muscular hypertrophy (20). Olympic lifts and plyometric exercises which require power should always be performed early in the training session.
Resistance training exercises can be classified by the movement pattern that occurs during the exercise. The major movement patterns are the press, pull, squat, lunge, flexion/extension, adduction/abduction, and rotation. Examples of each motion are given in Table 7.1. Developing a resistance training program requires the understanding of these motion patterns so that the program is effective and balanced. In order to provide variation these motion patterns may be combined.
Press motion: Bench press, Overhead press
Pull motion: Upright row, Pull-down
Squat motion: Squats, Dead lifts
Lunge motion: Lunge, Step-up
Flexion/extension motion: Crunch, Back hyperextensions
Abduction/adduction: Hip abduction, Hip adduction
Rotation: Shoulder rotation, Rotary crunches
Table 7.1: Motions of resistance training exercises
There are various methods of training that can be used in a training program. This section will discuss many of these methods and their application to tennis.
During a single-joint exercise only one joint undergoes movement, while a multi-joint exercise uses multiple muscle groups and joints at the same time. A biceps curl is an example of a single-joint exercise. A lunge is an example of a multi-joint exercise because it requires movement at the hip, knee, and ankle. Multijoint exercises require more complex neural activation and coordination, and they are also more effective at increasing muscular strength and power (17, 18). Since tennis performance requires multi-joint movements, multi-joint exercises are more specific to tennis. Single-joint exercises also have less risk of injury because of the reduced level of skill and technique required to perform the lift (18). It is doubtful that single-joint exercises will have as much impact upon performance, although they can be used if there is a specific muscular imbalance or to help prevent injury to specific muscle groups.
Exercises can be categorized by which of three primary planes of motion they occur in. These three primary planes are the transverse, sagittal, and frontal planes. Exercises which occur in more than one plane are referred to as multiplanar exercises. Multiplanar exercises closely resemble the movements seen in tennis because the movements seldom occur in one of the primary planes. An example of a multiplanar movement is a cable lift where an athlete lifts a weight from low to high moving it across their body at the same time.
Free weight exercises use a free-standing load and require the athlete to stabilize the weight while moving it through a movement pattern. Additional muscle activation is required to stabilize the weight. The resistance of the free weight is constant, so the load that is lifted is limited by the weakest point in the range of motion. Because of the freedom of movement allowed by free weights, they can be used to mimic tennis specific movements. Dumbbells and barbells are both examples of free weights. An example of a tennis specific movement with free weights is a dumbbell lunge.
Figure 7.4: Free weights.
Machines provide a resistance training alternative to free weights. Many machines do not require that the weight be stabilized which tends to decrease the requirement for synergistic support and stabilization. Machines may be more appropriate for beginners who may be intimidated by free weights or unable to balance the load. Machines are also able to isolate specific muscles or muscle groups and are easier to learn. Because of this, machines can also be used to rehabilitate injuries and improve muscular imbalances.
Figure 7.5: Machines.
Using the athletes own body weight can be an effective form of resistance training. The ability to control your own body weight is critical for success in tennis. Exercises such as push-ups, pull-ups, and body-weight lunges all use body weight as the form of resistance.
Figure 7.6: Body weight.
Elastic tubing can be used as a form of resistance training. As the tubing is stretched, the resistance increases. This is not compatible with the human strength curve. Tennis players often use elastic tubing to perform prehabilitation exercises for the shoulder. Because of its small size and light weight, elastic tubing is easy to transport wherever you go. Since tennis players are often traveling this is an easy option for resistance training.
Figure 7.7: Elastic Tubing.
Functional training has become a popular method of training in recent years. Functional training emphasizes training movement patterns as opposed to muscle groups. Because tennis and almost all other sports are played in a standing position with no outside support, functional training emphasizes movements performed in a standing position without outside support such as with machines. Because sports are not played with single joints working in isolation, functional training also emphasizes multi-joint movements. Balance and proprioception are also an important part of functional training. There is a continuing debate regarding the benefits of functional training and the balance between functional training and isolated training.
There are multiple methods of structuring daily program design for tennis players. The choice of program depends on the ability level of the athlete as well as the stage of the periodized cycle.
In this program the athlete trains all major muscle groups in one day. This program is most often used with novice weightlifters or individuals with time constraints. During in-season phases of training, this will often be used because of the lack of time available for off-court training. This program should have one day of rest between each session and should be repeated no more than four times a week. In each session the total number of exercises performed should rarely exceed ten. Because of the limited training days and exercises available, the program must be both efficient and effective. The focus is on training major muscle groups, with few isolated single joint exercises included.
This program is usually used with more experienced lifters. It separates the body into two training days. On the first day the upper body is trained, and on the second day the lower body is trained. Core training may be structured as part of one training session or performed as a separate training session. Each session should not exceed ten exercises. Following the two training days is a rest day and then the cycle can be repeated again. This program allows for greater number of training days because of the ability to train on consecutive days. Extra rest days can be added as necessary to fit the goals of training and the tournament schedule. This program is most often used in the offseason or between tournaments when the athlete is trying to increase the number of training sessions.
Resistance training can be used to improve multiple aspects of athletic performance. By manipulating different training variables, resistance training can be used to improve muscular strength, power, and endurance.
General strength is important for tennis players to reduce injury risk and provide a base for power training. In order to improve strength, resistance training should use loads that represent approximately 60 to 80 percent of the 1RM. Rest periods can vary but should typically be 2-3 minutes in duration for primary exercises. The tempo for strength training should be submaximal. This tempo requires the recruitment of stabilizing muscle groups to control the weight. A submaximal tempo also provides variety from the maximal velocity power training which is necessary for tennis.
If the goal of the athlete is muscular hypertrophy, loads should be in the range of approximately 60 to 80 percent of the IRM. It is important that maximal effort is given in every set. In order for complete ATP recovery rest periods should generally be in the range of 2-3 minutes. Athletes who are focusing on muscle hypertrophy typically use multiples sets, and 6 to 12 repetitions (7). Hypertrophy training also uses up to four to six exercises for one muscle group in the same training session. Maximal hypertrophy is typically not a goal of most tennis players because they do not want to become too muscular and lose flexibility. However, for some players who lack muscle mass, some degree of muscle hypertrophy may be advantageous.
Power can be defined as the amount of work done per unit of time.
Therefore muscular power is a function of both strength and speed of movement. If two people lift the same weight but one lifts in a slow controlled manner and the other lifts it very quickly, the second person produces more power. Training for power improves the contributions of the neuromuscular system in several ways. Power training improves the rate at which force can be applied (10), increases muscular strength at both slow and fast contraction velocities (15), as well as improves coordination and movement efficiency (35). Each of these neural changes will lead to improved power on the tennis court. A significant strength base is necessary prior to performing the exercises involved in power development for maximal adaptation to occur.
When training for power, athletes should progress to sport-specific loads and velocities. Since tennis players must accelerate a light load extremely fast, training should move to this end of the force velocity curve. Research has shown that the use of light to moderate loads at high velocities increases force output at higher velocities (11). The optimal load for maximal power output has been shown to be between 30-60% of 1-RM depending on the choice of exercise (34, 3, 4). Rest between sets should be between 2-3 minutes to allow complete recovery between sets.
It has been suggested that simultaneously training for strength with heavy loads and power with light loads will provide the optimal increases in power output by increasing both the force and time components of the power equation (30).
Figure 7.8: Olympic lift is similar to the ready position.
Olympic Lifts/Modified Olympic Lifts. Olympic lifts and their variations are a common method of training for power improvement. The Olympic lifts are the clean and jerk and the snatch. There are numerous other lifts which are derived from these two lifts. Olympic lifts have been shown to produce the highest power outputs of any strength training exercise when performed correctly (8). These lifts are performed in a standing position and are a total body exercise requiring explosive movement and coordination. In addition, because the position of the body when performing an Olympic lift is similar to the ready position on the tennis court (Figure 7.8) they transfer well to sports performance. When performing Olympic lifts, speed of movement should be emphasized over the weight lifted. A disadvantage of Olympic lifting is that they require a lot of teaching and time to learn. If they are performed incorrectly they can lead to injury. When learning Olympic lifts, start with light weight and focus on correct technique.
Plyometrics. Another common training method to develop power is plyometric training. Plyometric exercises begin with a rapid stretching of the muscle in an eccentric contraction. This is immediately followed by a rapid concentric contraction. The time between the eccentric contraction and the concentric contraction is called the ammoritization phase. The goal of plyometric training is to shorten the ammoritization phase, thus increasing the power output. Rapidly combining eccentric and concentric actions increases the muscular force and power output during the concentric phase (33).
Lower-body plyometrics include various jumping and bounding drills for the purpose of improving lower-body power and explosiveness. Upper-body plyometrics include various medicine ball throwing exercises designed to improve upper body power and explosiveness.
Muscular endurance can be defined as the ability to repeatedly contract a muscle or muscle group over a short period of time. Because tennis matches can last several hours, muscular endurance is important so that players will be able to maintain power outputs late in the match. In order to improve muscular endurance, higher repetitions should be used along with low-to-moderate-intensity loads, generally below 60 percent of the 1RM (30). Short rest periods of 30 to 45 seconds should be used to simulate match conditions.
Circuit Training. Circuit training is a common method used to train muscular endurance. Circuit training uses stations which are completed one exercise after another. At each station there is an exercise to be performed for a specified number of repetitions or for a prescribed time period. Resistance training can be used at each station or some stations can use various conditioning exercises such as short sprints. Following each station there is a brief timed rest period. Circuits can range from 6-12 stations. Following the completion of a circuit there is a longer rest period. It is recommended that the rest periods follow tennis-specific guidelines. Therefore rest between stations would be less than 25 seconds and the rest between circuits would be 90 seconds to simulate the change of ends. The total number of circuits performed during a training session may vary from two to six depending on the training objective.
There are several advantages to performing circuit training. Due to the constant variation, circuit training provides a unique workout which may prevent boredom and overtraining. Because of the fast pace of the workout, circuit training is a highly efficient form of training. By alternating exercises and muscle groups each is given more time to rest before it is worked again. Circuit training is also very effective for training groups of players at the same time.
This chapter has discussed the major issues relevant to resistance training tennis players. The following chapter will give specific exercises and program designs which can be implemented.
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