Contemporary Techniques Linked to S&C
Bilateral vs Unilateral training for team sport athletes
Team sports consist of a variety of different techniques used over the period of play such as a footballer lunging for the ball or a rugby player squatting in the scrum; identifying that there is a mixture of bilateral and unilateral movements used in conjunction with each other (Gamble, 2013).
Bilateral training consists of using both limbs at the same time, in unison with one another for example bench presses, chin-ups and squats. Unilateral training is when the athlete’s limbs are working independently of each other for example lunges and dumbbell bent-over rows (Baechle and Earle, 2008). There has been much debate in recent research, about which resistance/strength training exercises are more beneficial for team sport athletes for muscular force production (Fleck and Karaemer, 2004).
One of the main arguments surrounding the debate of Unilateral vs Bilateral training is the bilateral deficit and its effect on performance (Dickin et al., 2011). The deficit affects all limbs, however, greater deficits have been found in the lower limbs of the body therefore (Gamble, 2013) identified that unilateral training was more effective as it didn’t allow an athlete to favour a dominant leg when performing the exercise. Additionally McCurdy et al., (2010) identified that movements in team sports were mainly completed when the athlete was standing on one leg, therefore unilateral training would promote dynamic correspondence from training to the game. Despite this, bilateral training has been proved to reduce the bilateral deficit (difference between the force developed during bilateral action and the sum of the force developed within each limb independently) (Secher, 1975) in sporting performance (Teixeira et al., 2013).
Within recent research however Strength and Conditioning coaches have argued that unilateral training has been more effective for their athletes because unilateral training improved overall bilateral movements (Hale et al., 2014).
Makaruk et al., (2011) agreed with this, however with the additional findings that when unilateral training was enforced it produced greater power of the athletes for a short period of time compared to bilateral training, whereas the increased performance gained from bilateral gains lasted for longer. A further suggestion of this research was to implement both unilateral and bilateral resistant training into an athlete’s regime to enhance and prolong the effects of training to further improve performance (Makaruk et al., 2011). A major limitation of this study however was that only untrained female participants were used, therefore limiting generalisation of results to wider populations or sport specific populations. Using different participants may have evoked different results.
Behm and Sanchez, (2013) researched instability resistance training across the exercise continuum and identified that unilateral resistance such as reducing the base of support of the athlete could disrupt the equilibrium of the musculoskeletal form. This created challenges of balance that may have a negative impact on the force produced by an athlete during a sporting event. The problem of balance promoted the use of unilateral training for athletes as it can activate core muscles to further enhance performance (Behm and Sanchez, 2013). Kim et al., (2011) supported this with results from a study using EMG signals to record muscle activity in abdominal muscles during unilateral exercises. Men and women were used in the study making results transferable to a wider population thus extending the amount of further research that could be carried out. Results showed that when participants performed the Single-Legged Hold in the Hook-Lying Position on an unstable surface compared to a stable surface, the internal oblique, bilateral rectus abdominals and external oblique muscle were stimulated more. Therefore if an athlete wanted to improve trunk stability, improving balance and in turn increasing the force produced (e.g. a rugby player in a rucking position), unilateral exercises performed on an uneven surface could be prescribed. Limitations however were that all participants used were right legged therefore there may have been a correlation with leg dominancy and abdominal muscle activity (Kim et al., 2011). Even though counteracting arguments have been made promoting the use of bilateral training such as, allowing the athlete to have a greater use of the percentage of the body’s overall musculostructure, further implications for the use of unilateral training cannot be overlooked.
Modern research undertaken by Jones et al., (2012) made an interesting finding when investigating the effects of unilateral and bilateral lower-body heavy resistance exercise on muscle activity and testosterone responses using ten male athletes, all resistance trained. It was identified that when subjects performed bilateral exercises weight distribution was varied over each side of the body, however with unilateral exercises this was not possible thus putting greater demand on the neuromuscular system. Therefore muscle activation from unilateral exercises were similar to bilateral exercises indicating that athletes should use unilateral training with high resistance loads compared to an abundance of bilateral training with heavy resistance loads to get the same result (Jones et al., 2012). Cross education can also occur when a player is using unilateral training exercises; at the same time the untrained limb is also increasing in strength thus improving strength in overall bilateral movement, due to neural adaptations, so the athlete is working for less (McCurdy et al., 2010). A further advantage of unilateral training is that it allows coach/player to see weaknesses and imbalances in muscles of their athletes (Witkowski et al., 2011)
In conclusion, there is an abundance of research supporting the use of unilateral training. However, using both training exercises allowing differentiation in the training programme, enables athletes to break from standard exercises when they start to adapt to unilateral exercises and experience fewer gains (Fleck and Karaemer, 2004). Therefore for optimal training it was suggested that the athlete used bilateral and unilateral training together, but basing the ratio of the training on the needs of the sport (Ratamess, 2012). Additionally the American College of Sports Medicine recommended that both unilateral and bilateral training should be implemented into an athlete’s Resistance Training regime to enhance effective progression (American College of Sports Medicine , 2009).
Reference list:
American College of Sports Medicine , (2009) position stand. Progression models in resistance training for healthy adults. Medicine and Science in Sports and Exercise . Vol. 41: 687-708.
Baechle, T.R. and Earle, R.W. (2008) Essential of Strength Training and Conditioning . (3rd ed.) United states : Human Kinetics.
Behm, D. and Sanchez, J. (2013) Instability resistance training across the exercise continuum.. Sports Physical Therapy . Vol. 5, No. 6: 500-3.
Dickin, D.C., Sandow, R. and Dolny, D.G. (2011) Bilateral deficit in power production during multi-joint leg extensions. European Journal of Sport Science. Vol. 11, No. 6: 437?445.
Fleck , S.J. and Karaemer, W.J. (2004) Designing resistance training programs . (3rd ed.) United States : Human Kinetics .
Gamble, P. (2013) Strength and Conditioning for Team Sports: Sport-Specific Physical Preparation for High Performance . (2nd ed.) Oxon : Routledge .
Hale, S.A., Fergus, A., Axmacher, R. and Kiser, K. (2014) Bilateral Improvements in Lower Extremity Function After Unilateral Balance Training in Individuals With Chronic Ankle Instability. Journal of Athletic Training. Vol. 49, No. 2: 181–191.
Jones , M., Ambegaonkar, J., Nindl, B., Smith, J. and Headley, S. (2012) Effects of unilateral and and bilateral lower body heavy resistance exercise on muscle activity and testosterone responses . The Journal of Strength and Conditioning Research. Vol. 26, No. 4: 1094–1100 .
Kim, S., Kwon, O., Yi, C. and Jeon, H. (2011) Comparison of Abdominal Muscle Activity During a Single-Legged Hold in the Hook-Lying Position on the Floor and on a Round Foam Roll . Journal of Athletic Training. Vol. 46, No. 4: 403-8.
Makaruk, H., Winchester, J., Sadowski, J., Czaplicki, A. and Sacewicz, T. (2011) Effects of unilateral and bilateral plyometric training on power and jumping ability in women . Journal of Strength and Conditioning Research. Vol. 0, No. 0: 1-8.
McCurdy, K., O’Kelley, E., Kutz,, M., Langford, G., Ernest, J. and Torres, M. (2010) Comparison of lower extremity EMG between the 2-leg squat and modified single-leg squat in female athletes. Journal of Sport Rehabilitation. Vol. 19: 57-70.
Ratamess, N. (2012) ACSM'S Foundations of Strength Training and Conditioning . United States : Lippincott Williams & Wilkins .
Secher, N.H. (1975) Isometric rowing strength of experienced and inexperienced oarsmen.. Medicine ans Science in Sports . Vol. 7, No. 4: 280-3.
Teixeira, A., Narciso, J., Salomão, I. and Dias, M. (2013) Bilateral Deficit in Maximal Isometric Knee Extension in Trained Men. Journal of Exercise Physiology. Vol. 16, No. 1: 68-35.
Witkowski, Z., Lyakh, V., Gutnik, B., Lipecki, K., Rutowicz, B. and Penchev, B. (2011) Corrective effects of different training options on development and maturation of professional motor skills from dominant and non-dominant legs of young soccer players. Journal of Physical Education and Sport. Vol. 11, No. 3: 291-299.
Bilateral training consists of using both limbs at the same time, in unison with one another for example bench presses, chin-ups and squats. Unilateral training is when the athlete’s limbs are working independently of each other for example lunges and dumbbell bent-over rows (Baechle and Earle, 2008). There has been much debate in recent research, about which resistance/strength training exercises are more beneficial for team sport athletes for muscular force production (Fleck and Karaemer, 2004).
One of the main arguments surrounding the debate of Unilateral vs Bilateral training is the bilateral deficit and its effect on performance (Dickin et al., 2011). The deficit affects all limbs, however, greater deficits have been found in the lower limbs of the body therefore (Gamble, 2013) identified that unilateral training was more effective as it didn’t allow an athlete to favour a dominant leg when performing the exercise. Additionally McCurdy et al., (2010) identified that movements in team sports were mainly completed when the athlete was standing on one leg, therefore unilateral training would promote dynamic correspondence from training to the game. Despite this, bilateral training has been proved to reduce the bilateral deficit (difference between the force developed during bilateral action and the sum of the force developed within each limb independently) (Secher, 1975) in sporting performance (Teixeira et al., 2013).
Within recent research however Strength and Conditioning coaches have argued that unilateral training has been more effective for their athletes because unilateral training improved overall bilateral movements (Hale et al., 2014).
Makaruk et al., (2011) agreed with this, however with the additional findings that when unilateral training was enforced it produced greater power of the athletes for a short period of time compared to bilateral training, whereas the increased performance gained from bilateral gains lasted for longer. A further suggestion of this research was to implement both unilateral and bilateral resistant training into an athlete’s regime to enhance and prolong the effects of training to further improve performance (Makaruk et al., 2011). A major limitation of this study however was that only untrained female participants were used, therefore limiting generalisation of results to wider populations or sport specific populations. Using different participants may have evoked different results.
Behm and Sanchez, (2013) researched instability resistance training across the exercise continuum and identified that unilateral resistance such as reducing the base of support of the athlete could disrupt the equilibrium of the musculoskeletal form. This created challenges of balance that may have a negative impact on the force produced by an athlete during a sporting event. The problem of balance promoted the use of unilateral training for athletes as it can activate core muscles to further enhance performance (Behm and Sanchez, 2013). Kim et al., (2011) supported this with results from a study using EMG signals to record muscle activity in abdominal muscles during unilateral exercises. Men and women were used in the study making results transferable to a wider population thus extending the amount of further research that could be carried out. Results showed that when participants performed the Single-Legged Hold in the Hook-Lying Position on an unstable surface compared to a stable surface, the internal oblique, bilateral rectus abdominals and external oblique muscle were stimulated more. Therefore if an athlete wanted to improve trunk stability, improving balance and in turn increasing the force produced (e.g. a rugby player in a rucking position), unilateral exercises performed on an uneven surface could be prescribed. Limitations however were that all participants used were right legged therefore there may have been a correlation with leg dominancy and abdominal muscle activity (Kim et al., 2011). Even though counteracting arguments have been made promoting the use of bilateral training such as, allowing the athlete to have a greater use of the percentage of the body’s overall musculostructure, further implications for the use of unilateral training cannot be overlooked.
Modern research undertaken by Jones et al., (2012) made an interesting finding when investigating the effects of unilateral and bilateral lower-body heavy resistance exercise on muscle activity and testosterone responses using ten male athletes, all resistance trained. It was identified that when subjects performed bilateral exercises weight distribution was varied over each side of the body, however with unilateral exercises this was not possible thus putting greater demand on the neuromuscular system. Therefore muscle activation from unilateral exercises were similar to bilateral exercises indicating that athletes should use unilateral training with high resistance loads compared to an abundance of bilateral training with heavy resistance loads to get the same result (Jones et al., 2012). Cross education can also occur when a player is using unilateral training exercises; at the same time the untrained limb is also increasing in strength thus improving strength in overall bilateral movement, due to neural adaptations, so the athlete is working for less (McCurdy et al., 2010). A further advantage of unilateral training is that it allows coach/player to see weaknesses and imbalances in muscles of their athletes (Witkowski et al., 2011)
In conclusion, there is an abundance of research supporting the use of unilateral training. However, using both training exercises allowing differentiation in the training programme, enables athletes to break from standard exercises when they start to adapt to unilateral exercises and experience fewer gains (Fleck and Karaemer, 2004). Therefore for optimal training it was suggested that the athlete used bilateral and unilateral training together, but basing the ratio of the training on the needs of the sport (Ratamess, 2012). Additionally the American College of Sports Medicine recommended that both unilateral and bilateral training should be implemented into an athlete’s Resistance Training regime to enhance effective progression (American College of Sports Medicine , 2009).
Reference list:
American College of Sports Medicine , (2009) position stand. Progression models in resistance training for healthy adults. Medicine and Science in Sports and Exercise . Vol. 41: 687-708.
Baechle, T.R. and Earle, R.W. (2008) Essential of Strength Training and Conditioning . (3rd ed.) United states : Human Kinetics.
Behm, D. and Sanchez, J. (2013) Instability resistance training across the exercise continuum.. Sports Physical Therapy . Vol. 5, No. 6: 500-3.
Dickin, D.C., Sandow, R. and Dolny, D.G. (2011) Bilateral deficit in power production during multi-joint leg extensions. European Journal of Sport Science. Vol. 11, No. 6: 437?445.
Fleck , S.J. and Karaemer, W.J. (2004) Designing resistance training programs . (3rd ed.) United States : Human Kinetics .
Gamble, P. (2013) Strength and Conditioning for Team Sports: Sport-Specific Physical Preparation for High Performance . (2nd ed.) Oxon : Routledge .
Hale, S.A., Fergus, A., Axmacher, R. and Kiser, K. (2014) Bilateral Improvements in Lower Extremity Function After Unilateral Balance Training in Individuals With Chronic Ankle Instability. Journal of Athletic Training. Vol. 49, No. 2: 181–191.
Jones , M., Ambegaonkar, J., Nindl, B., Smith, J. and Headley, S. (2012) Effects of unilateral and and bilateral lower body heavy resistance exercise on muscle activity and testosterone responses . The Journal of Strength and Conditioning Research. Vol. 26, No. 4: 1094–1100 .
Kim, S., Kwon, O., Yi, C. and Jeon, H. (2011) Comparison of Abdominal Muscle Activity During a Single-Legged Hold in the Hook-Lying Position on the Floor and on a Round Foam Roll . Journal of Athletic Training. Vol. 46, No. 4: 403-8.
Makaruk, H., Winchester, J., Sadowski, J., Czaplicki, A. and Sacewicz, T. (2011) Effects of unilateral and bilateral plyometric training on power and jumping ability in women . Journal of Strength and Conditioning Research. Vol. 0, No. 0: 1-8.
McCurdy, K., O’Kelley, E., Kutz,, M., Langford, G., Ernest, J. and Torres, M. (2010) Comparison of lower extremity EMG between the 2-leg squat and modified single-leg squat in female athletes. Journal of Sport Rehabilitation. Vol. 19: 57-70.
Ratamess, N. (2012) ACSM'S Foundations of Strength Training and Conditioning . United States : Lippincott Williams & Wilkins .
Secher, N.H. (1975) Isometric rowing strength of experienced and inexperienced oarsmen.. Medicine ans Science in Sports . Vol. 7, No. 4: 280-3.
Teixeira, A., Narciso, J., Salomão, I. and Dias, M. (2013) Bilateral Deficit in Maximal Isometric Knee Extension in Trained Men. Journal of Exercise Physiology. Vol. 16, No. 1: 68-35.
Witkowski, Z., Lyakh, V., Gutnik, B., Lipecki, K., Rutowicz, B. and Penchev, B. (2011) Corrective effects of different training options on development and maturation of professional motor skills from dominant and non-dominant legs of young soccer players. Journal of Physical Education and Sport. Vol. 11, No. 3: 291-299.