A New Look At Specificity!

Can the development of (for example) strength in a particular exercise (say, the squat) lead to strength improvements in the target sport skill (say, a volleyball serve)? Does transfer even exist? Get your technical questions answered!
One of the most enduring issues in sport training is the controversy over whether or not supplementary exercises can be designed in a way to have significant "positive transfer" to the athlete's sport skills. On one side of the argument are those who suggest that some exercises are more specific than others and therefore transfer better to the targeted sport skill. Others deny this possibility, stating that "there are no degrees to specificity - either it's specific, or it isn't.

There are several practical questions related to this discussion:

1) Can the development of (for example) strength in a particular exercise (say, the squat) lead to strength improvements in the target sport skill (say, a volleyball serve)?

2) If the answer to the previous question is "yes," then can the reverse also be true? In other words, can time spent on a particular exercise actually hinder a sport skill?

3) Is the most effective way to improve one's strength in a sport skill simply to overload the skill itself (for example, sprinting into a head wind or using an overweight racket in tennis)?

Does Transfer Even Exist?

Most contemporary experts say "yes." One familiar scenario that strongly suggests the existence of positive transfer is the experienced powerlifter who tries power cleans for the first time ever. On his first day, he cleans 250 pounds for example. The question is, where did this athlete get the strength required to clean 250? Obviously not from performing cleans! The most obvious answer is that the athlete's previous life experiences (primarily, but not limited to, training experiences) are what developed the strength necessary to clean 250 pounds. As a powerlifter, this athlete has performed a large number of squats, deadlifts and other strength training exercises which are probably the most likely causes of the "clean-specific" strength he possesses. Structurally, the deadlift is most similar to the clean, so those believing in specificity might move that particular exercise to the front of the list.

Reversing the above scenario, many Olympic weightlifters, who rarely if ever perform deadlifts, will be strong on this exercise right from the start, should they choose to practice that particular lift.

One might also logically argue that other types of athletes who lack experience in heavy lower body strength training (such as water polo players for example) might not be so successful when first attempting a power clean.

The Role of Supplementary Strength Training

The purpose of supplementary exercises is to develop motor qualities (such as strength, endurance, flexibility and so on) which are expected to have positive transfer to the sport skill, and which cannot be effectively developed by practicing the sport itself.

As a practical example, experience has shown that initially, participation in a sport will, by itself, develop the pertinent motor qualities needed for success in that sport. 1500 meter runners develop endurance by running 1500 meters. Baseball players develop throwing strength by throwing. Tae Kwon Do players develop flexibility by kicking.

Inevitably however, the athlete will reach a point where sport participation on its own will no longer be enough to improve the motor qualities needed. The 1500-meter runner finds that she can develop even better endurance by running 400-meter intervals in addition to her normal regimen of 1500-meter runs. The baseball player finds that his throwing strength improves even further by specific strength exerciser for his shoulder girdle. The Tae Kwon Do player develops even better flexibility by supplementary flexibility exercises.

Note: In some instances, the sport itself may theoretically ALWAYS be the best method of developing a quality needed for that sport, but supplementary training may still be a better option. Example: In boxing, the most specific way to develop sport-specific endurance is boxing itself. however, this option is not always practical, since the amount of boxing necessary to develop the needed endurance will also result in injuries and psychological stress. In cases like this, supplemental activities such as cycling, rope-skipping, running, etc., are used to develop endurance. In the case of each activity, the more similar it is to actual sparring, the more transfer of endurance will occur, but at the same, time, you'll also have the same negative outcomes as well. For example, sparring drills (such as using focus mitts) are sport-specific, but are also stressful and have a higher probability of causing injuries, compared to activities such as swimming or cycling.

Three Types of Transfer

A supplementary training exercise can have three possible effects on the target sport skill:

1) It can improve the target sport skill.

2) It can damage the target sport skill.

3) It can have little or no effect on the target sport skill.

Of course, in order for supplementary exercises to positively impact the target sport skill however, they must have what is called "positive transfer." Let's examine a practical example of how three different exercises can have three completely different effects on a particular sport skill, namely, the volleyball serve.

In this hypothetical example, the athlete has chosen three supplementary strength training exercises: the bench press, the barbell squat and biceps curls.


Bench Press Exercise: As the volleyball itself is the primary object against which the upper body musculature must exert force, we can conclude that there is no compelling need to develop significant levels of strength in the pectoral, front deltoid and triceps muscles. Also, significant efforts spent on the bench press exercise may have negative outcomes as well, including shortening of the pectoralis muscles, which may possible hinder certain skills where the arms are overhead, such as serving and blocking. Another possible negative outcome is the development of upper body muscle mass. This is problematic because upper body weight does not contribute to jumping or running ability. Bottom line: although the bench press may certainly be included in strength training programs for volleyball players, it by no means should be stressed as a key exercise, for the reasons stated above.

Barbell Squat: Many studies, as well as experience in the field, have demonstrated that improved strength in the squat leads to improved vertical jumping and running abilities- vital skills for volleyball players. In order for the squat to have positive transfer however, it must be performed with loading parameters that encourage the appropriate motor qualities (in this case, speed strength). Performing the squat for high repetitions for example, would actually de-train speed strength performance, and instead improve strength-endurance capacity. Bottom line: the barbell squat, if performed with loading parameters which encourage speed strength development, should be a key exercise for volleyball players.

Biceps Curl: Volleyball does not require the need for conspicuous levels of strength, hypertrophy, or endurance in the motion of elbow flexion. Therefore, other than diverting time and energy that could be used for better purposes, this exercise has neither positive or negative transfer to volleyball skills. Bottom Line: although the biceps curl may be included in strength training programs for volleyball players, it by no means should be stressed as a key exercise, as it has neither a positive or negative effect on the target skills needed.

Let's continue our discussion by addressing the three questions posed at the beginning of this article:

1) Can the development of strength in a particular exercise (say, the squat) lead to strength improvements in the target sport skill (say, a volleyball serve)?

Answer: Yes, if the supplementary exercise is carefully selected, and trained using loading parameters which enhance the desired motor qualities.

2) If the answer to the previous question is "yes," then can the reverse also be true? In other words, can time spent on a particular exercise actually hinder a sport skill?

Answer: Yes. If the supplementary exercise is NOT carefully selected, and trained using inappropriate loading parameters with respect to the desired motor qualities.

3) Is the most effective way to improve one's strength in a sport skill simply to overload the skill itself (for example, sprinting into a head wind or using an overweight racket in tennis)?

Answer: Yes and No. Some sport skills can be effectively overloaded without negatively affecting the structure and coordination patterns involved in these skills, while other skills are inherently difficult to overload in the same manner.

For example, punching with dumbbells in the hand is similar to the act of punching, yet the additional weight would certainly disrupt the correct motor patterns used in punching. This is because the application of force in a punch is horizontal with respect to the ground, while punching with dumbbells in one's hands requires horizontal extension of the arm while being resisted from above.

On the other hand, some sport skills can be easily overloaded with great results. For example, throwers in track and field often effectively use a slightly underweight implement to improve speed and slightly overweight implement to improve specific strength. Even so, it is widely known that implements which vary too much (in terms of weight) from the competition implement will disrupt correct motor patterns.

In the case of the thrower who uses an excessively heavy implement in an effort to improve sport-specific strength, the following analogy may be instructive: People who borrow a friend's car frequently have difficulty finding the ignition, locating the brake pedal, or getting used to the steering wheel. This scenario doesn't occur when riding a bike, or a motorcycle, or a riding mower however. It seems to only appear in vehicles which are similar (yet still different) to one's own car. This is because when someone performs the same movement may thousands of times, highly-ingrained motor patterns develop.

Specific to WHAT?!

There is a strong tendency to consider only the structure of the sport skill when devising strength training exercises which positively transfer to that skill. however, the exercise structure is but only one consideration. Others include:

1) Contraction Type: Is the sport skill characterized by eccentric immediately followed by concentric contraction, such as throwing, sprinting, and jumping? Or does the skill begin concentrically, such as the deadlift in powerlifting? Further still, some skills are primarily static (the iron cross is men's gymnastics) or eccentric (landing from a jump). Whatever the case, for maximum transfer, supplementary training should reflect the primary type of contraction. One particularly interesting study illustrates this reality:

* Ribeiro, B. V., Castro, A. S., Carvalho, B., & Weltman, A. (1998). Study of the specificity between the training and the evaluation method of the muscle strength. Medicine and Science in Sports and Exercise, 30(5), Supplement abstract 658.

This study evaluated the degree of specificity between concentric isokinetic and dynamic concentric evaluation after 8 weeks of dynamic concentric training of the quadriceps muscles. Eight novice weight trainers and seven sedentary persons served as subjects.

The weight training group improved in both the left and right quadriceps but the improvement was greatest on the dynamic test as opposed to the isokinetic test. The sedentary group did not change at all.

Implication: For strength training changes to be measured, the assessment contraction form should be the same as that used in training. Training forms are specific in strength training.

2) Velocity: Many studies confirm that strength training exercises should be conducted at the same or similar speed for the best hopes of positive transfer. Just a few of the more pertinent abstracts include:

* Liow, D. K., & Hopkins, W. G. (1998). Velocity specificity of heavy weight training for kayak sprint performance. Medicine and Science in Sports and Exercise, 30(5), Supplement abstract 621.

39 Experienced male and female kayakers were matched by sex and sprint time and randomly assigned to a slow weight training, explosive weight training, or control (normal training) group. Weight training using sport-specific exercises was performed twice a week for six weeks. Possible effects were measured by having subjects sprint 15 meters.

It was found that at the very start, when movements were slow, the slow-training group improved most (6.9%), the fast group next (3.2%), and the control group least (1.4%). Over the last 3.75 m the fast training group improved most (3.0%), the slow group next by (2.1%), and the control least (-0.8%).

Implication: Slow weight training exercises train one to respond best when moving slow. Fast weight training exercises train athletes to respond best when moving fast. However, both forms of training improve performances better than no weight training.

* Young, W., McLean, B., & Ardanga, J. (1995). Relationship between strength qualities and sprinting performance. Journal of Sports Medicine and Physical Fitness, 35, 13-19.

The relationships between strength measures and various phases of sprinting performance were determined. 11 male and 9 female Elite junior track and field athletes performed maximum 50 meter sprints being timed at 2.5, 5, 10, 20, 30, 40 and 50 meters. Resultant applied forces were measured with two force platforms. 27 measures of strength and speed-strength were measured from height jumped and force-curve from take-off using pure concentric, stretch shortening cycle and isometric muscular contractions.

The best predictor of starting performance (2.5-meter time) was the peak force relative to body weight generated during a jump from a 120-degree knee angle (concentric contraction). The single best correlate of maximum sprinting speed was the force relative to body weight applied at 100 meters from the commencement of a loaded jumping action (concentric contraction).

* Implications: The angle of the legs to generate the best start over 2.5 meters should be in the vicinity of 120 degrees at the knees. Maximum running speed depends upon the ability of the runner to generate force quickly, that is, in about 100 meters, almost the length of time that the foot is in contact with the ground. The contact time for males averaged 101 meters and 108 meters for females. Thus, unless strength training trains the ability of the legs to generate forces in a very short time, that is, with maximum explosive force, slower training would not assist in the development of running speed. Strength training for sprinters should emphasize the most rapid development of leg forces.

3) Force-Posture Relationship: In any given skill, force production varies throughout the range of motion of that skill. Supplementary strength exercises which cause maximal force production at the specific joint angles where force must be highest in the sport skill, will have the greatest positive transfer to that skill. Example: Athletes who must perform vertical jumping skills (volleyball, basketball, high jump, etc) exert the greatest forces in a shallow squat-crouch which preceded the jump. Therefore, in strength training, squats which approximate the same joint angles used in jumping will generally have greater transfer than squats which are deeper than this position.

Practical Recommendations For Maximum Strength Transfer

1) Whenever practical, use the sport skill itself to develop the desired motor qualities.

2) When not possible, the following apples:

* Some sport skills can be "overloaded" with a high degree of success. These include:

Method of Overload
Running up a slight grade
Running into a slight head wind
Running with a resistive parachute
Running while towing a partner with a cord
Swimming into a current
Swimming with resistive clothing
Cycling uphill
Cycling in a lower gear
Cycling into a head wind
Throwing slightly overweight implements
Jumping with weighted clothing
Jumping while tethered to the ground with elastic cord
Combat Sports
Sparring with a larger/heavier opponent

* For athletes who's sport skills do not easily lend themselves to overloading (soccer, basketball, skiing, etc), the best approach is to emphasize strength training exercises which represent fundamental movement patterns (e.g. squatting, lunging, pushing, pulling, etc) in order to improve inter-and intra-muscular coordination, recruitment of fast-twitch muscle fibers, and maximal strength. Later, during the performance of the sport skills, the body will learn how to apply its new strength levels to the target skill.

3) When training involves large-muscle total-body activities, such as running, rowing or Olympic weight-lifting, there can be a partial but minor transfer of training effects to simpler activities. For example, aerobic improvements derived from running (a complex activity) have been shown to produce improvements in the aerobic work of cycling (a simpler activity where the work occurs in fewer large muscle groups). The amount of the transfer is marginal at best, however. For example, the aerobic benefits that could be derived from 10 hours of endurance running might translate into the equivalent effect of 1 hour of endurance training for cycling. In such cases, it might be more economical to simply train for 1 hour on a bicycle rather perform 10 times as much running training to get an improvement in cycling. Also, cycling produces specific endurance effects plus other associated benefits (which would not result from relying on the transfer of the running-training phenomenon).

4) When supplementary training involves a relatively simple activity, the benefits of that training are specific and do not transfer to more complex activities. In other words, the reverse of what has been explained above in point #5 does not occur. When an individual trains aerobically for cycling and shows marked training effects there is no transfer of aerobic benefits to running. Similarly, specific weight exercises do not cause improvements in the more complicated Olympic lifts (which require a high degree of complex skilled movement). Thus, when considering supplementary training exercises that are supposed to benefit a particular sport, if those exercises are simple, they will not be beneficial for an athlete. If they are performed with sustained intensity, they actually could prove to be counter-productive, primarily because of the development of unnecessary fatigue that could hinder more beneficial recovery.

5) There are at least four circumstances where generalized supplementary training can be beneficial:

* Rehabilitation from injury is facilitated by general activities and specifically designed localized programs to promote tissue repair;

* Generalized resistance exercises and other forms of training can be used to prepare the body for unusual and/or unpredictable circumstances that can occur in competitions and thus, serve as a method for lessening the likelihood of injury;

* General endurance training has general behavioral effects that are beneficial to target sports, and sports where attention and decision making are crucial elements (e.g. yachting, playing in-goal in ice-hockey); and ...

* General training is particularly beneficial if the fitness level of the athlete is particularly low. This is true of both young performers and adults starting new activities. When the new performer is so low in general fitness characteristics any improvement in them, whether or not they are specific, will be beneficial. However, those benefits are only displayed when the level of performance is very low. As performance improves in the sport, the value of any transfer of general or unrelated training effects diminishes rapidly.

Ultimately, supplementary exercises will be most effective when they enhance qualities which are a) needed but poorly developed, b) foundational to other qualities and c) highly trainable, given available resources. In other words, focus on bringing up weaknesses.


Charles Staley is a sports conditioning specialist and director of Integrated Sport Solutions in Las Vegas, Nevada. A former martial arts competitor and trainer, Staley is also an Olympic weightlifting coach, as well as a master's level track and field competitor (discus event). He has coached elite athletes from many sports, including martial arts, luge, boxing, track and field, bobsled, football, Olympic weightlifting, and bodybuilding. Staley has written hundreds of published articles, and has lectured extensively on the topics of human performance and sport training.