In the attempt to improve athletic performance or prevent sports-related injuries, it is common to read that muscles in the body should be balanced. At times, what “balanced” means is never fully explained and is often assumed to mean that muscles on both sides of a joint should be equal in qualities such as endurance or strength. As a result, trainers and coaches may advise athletes to perform equal training for musculature on all sides of a joint to ensure balance.

The intent is to achieve symmetry. Not just at one particular joint, but often throughout the body. The goal is to see symmetrical movement on both sides of the body. Consider how therapists and coaches will use movement-screening systems to evaluate movement and then apply correctives with the goal to ‘balance’ the body or to reduce the risk of injury.

However, one must question if this the most intelligent thing to do in relation to high-level athletic performance. 
From the few studies done on this topic and from observation, symmetry may not be an effective means of improving performance. Rather, It appears that the majority of high-level athletes are asymmetrical.

This should not be surprising if you have been looking closely at high-level athletes. I recently attended the ACA Rehabilitation Symposium in Las Vegas over this past weekend. Professor Stuart McGill was one of the featured speakers and he has extensively researched the factors which make great athletes great. Professor McGill provided numerous examples from cases he has seen over of the years of athletes being ruined by someone attempting to 'balance' their body. The intent was on improving their performance or ‘correcting’ movement, yet the end result was making that athlete a patient. Essentially, he cautioned us all as chiropractors, therapists, and trainers to be very wise in what we do with our athletes.

One example he provided was Olympic sprinters and how many of them have very stiff, tight ankles. He stated how this is necessary for their performance and ultimately their success as elite level sprinters. Their ankles must be stiff to serve as ‘springs’ for explosive running. Yet, as he stated, many therapists would want to ‘mobilize’ their ankles and ‘release’ or ‘stretch’ the musculature surrounding the ankle to improve range of motion. However, now you have robbed them of the very thing that makes them a great athlete in their sport.

His example brought to mind a high school football player who trains at GP. He is our fastest athlete and his ankles are incredibly stiff. This stood out immediately upon his initial assessment. Did we do anything to mobilize his ankles? No. We didn’t touch his ankles, understanding that his ankle stiffness is what made him fast. Made him incredibly agile and quick.

If you try to balance muscular development or joint function, it can potentially interfere greatly with an athlete’s performance. It’s important to remember that what makes athletes asymmetrical also makes them great. It is not only a consequence of their training, but often what their sport demands. To take time out of their training to balance their body arguably interferes with more productive training.

This does not mean that they do not do exercises to keep their body healthy and prevent injury. We have our athletes perform many exercises for this purpose, but they are typically done during the general preparatory period, not in the competitive or precompetitive periods.

Former Soviet Union sport scientists studied this concept. The Soviets understood that asymmetry appears to be a key to athletic success. Asymmetry that is produced appears to allow athletes to go above and beyond what other ”well-balanced” athletes are capable of doing. It seems that the asymmetry allows the athlete to perform on a higher level.

There appears to be enough evidence to indicate that perhaps we should not be anxious to 'balance' every athlete’s physical development. Keep in mind that this does not mean that you ignore development of antagonistic muscles. But you do not emphasize them to the same extent as you do with the main muscles and joints involved in the execution of the athlete's competitive sports skill.

More related reading:

https://gallagherperformance.com/athletic-development-will-your-child-be-a-success-or-burn-out/

https://gallagherperformance.com/does-practice-make-permanent-how-practice-rewires-your-nervous-system/

https://gallagherperformance.com/commonmistakesindevelopingyoungathletes/