As the days become shorter and the temperatures start to drop, many cyclists will soon review their progress from the 2007 cycling season and set goals for 2008. In addition, many cyclists will begin cross training to maintain their existing fitness and focus on muscle groups that have been neglected. It is important to note that neglected muscle groups can result in muscle imbalances and asymmetry that have an impact on the cyclist’s performance and comfort on the bike.

The detection of muscle imbalances and correcting them before injury occurs is critical to cycling longevity and performance. Most cyclists develop muscle imbalances due to over use of the hip flexors (mobilizers) and under use of weak gluteus muscles (stabilizers). This type of muscle imbalance can cause the pelvis to tilt upward and extend the lumbar spine causing a lordotic tilt (arched lower back) of the pelvis.

Cyclists should conduct periodic screenings for muscle imbalances and correct the abnormalities of muscle strength and length to prevent musculoskeletal pain and irregular function. Evaluating muscle length is not difficult via standardized tests.  However, evaluating muscle strength can be more challenging. The primary focus on evaluating muscle strength is to be able to isolate the action of individual muscles. The majority of muscle strength evaluation concentrates on testing the mobilizers (hamstrings, adductors, hip flexors and abdominal recti) because they are easier to isolate than stabilizers (transversus abdominis and posterior glutei mediae).  If the cyclist is unfamiliar with muscle imbalance testing they should look for a professional to evaluate them and make sure a protocol is established to assess both the mobilizers and stabilizers.

As discussed earlier, muscle imbalances can cause a lordotic tilt of the pelvis. The tilt of the pelvis can also be more pronounced on one side of the body due to asymmetry where one side of the body is more dominant than the other.

There are many factors to consider when addressing muscle asymmetry.  However, there are two primary factors that cause muscle asymmetry while riding the bike. The first is bike fit and proper rider positioning on the bike.  Muscle asymmetry will become more pronounced if the rider is on the bike incorrectly.  A major factor to determine if the cyclist is on their bike correctly is if he or she is able to engage their core muscles while sitting on the saddle of the bike.  If the cyclist cannot engage their core muscles, there is dysfunctional stabilization and no lumbopelvic stability.  When the cyclist lacks core stability he or she will be pedaling outside their natural alignment and more muscular effort is required to recover to a stable position.  In short, while pedaling long distances the dominant side muscles groups begin to work more than the less dominant side muscle groups, thus causing more muscle asymmetry.

The second factor to consider when addressing muscle asymmetry is the cyclist’s riding habits.  For example, reaching down for a water bottle with the same hand reinforces muscle asymmetry.  Another example is while stopping at an intersection and extending the same leg to the ground while the other leg remains contracted reinforces muscle asymmetry.  A third example is looking back over the same shoulder when checking for traffic reinforces muscle asymmetry.  To test your level of asymmetry do what I call “the one-armed interval.”

To do the “one-armed interval” all you do is ride your bike for 5 to 10 minutes with only one arm on the handle bars at an easy pace.  Then switch arms and ride another 5 to 10 minutes with only the other arm on the handle bars.  If you are right side dominant, you will notice while riding with your right hand on the handle bars and your left hand off the bars, your left glutes (stabilizers) and left side core muscles will be working harder than when you were riding with the left hand on the handle bars.  When your left hand is on the handle bars and you are right side dominant, your glutes and right core muscle groups are not nearly as taxed.

There is no easy answer to eliminating muscle imbalances.  The only way to prevent or eliminate injuries is to learn where you have muscle imbalances and adjusting them with the correct strengthening and flexibility exercises.  Once you understand more about your muscle imbalances begin a daily stretching and strengthening routine.  Doing yoga and/or pilates is a great way to strengthen weak muscles and lengthen tight muscles.