When an athlete is injured one of the first things they ask is “What strengthening exercises can I do” as if the reason they were injured was due to a lack of strength and not overtraining. While strengthening may play a part the fact is most repetitive strain injuries are due to not enough recovery rather than a lack of strength. I always like to ask the patient “How strong do you have to be to prevent injury”? This is usually met with a questioning look and sometimes a glare. So how strong do you have to be? What kind of strength is important in preventing injury?
Strength can be measured in a couple of ways, for example, Absolute Strength can be measured by assessing a person’s ability to exert a maximum amount of force in a single effort. While this may be important in some instances (like Power lifting) it is unlikely that most people care or need to improve their Absolute Strength. On the other hand there is Endurance Strength. This type of strength trains your muscles and heart to be stronger for long periods of effort (like mid or long distance running or soccer). Muscles respond to what is called the SAID Principle, that means, Specific Adaption’s to Imposed Demands. This means that if you desire to have Endurance Strength you must train the muscle in a way that requires effort from the muscle for an extended period of time (high repetitions). Another aspect of the SAID Principle is that muscles will naturally strengthen in response to loads placed on them. For example; if you trained your quadriceps to be strong by cycling they would be strong while cycling, not running. If you sustain an injury while running, and try to strengthen the muscle by cycling, doing leg extensions or balancing on a Bosu Ball you will be stronger doing those specific things. However, you will not be stronger while running nor will you prevent further running injuries. The above concepts are difficult for the average person to grasp and because of this there is much misinformation spread to the public on how to properly rehabilitate an injury or gain strength to prevent one. What does this mean to the athlete that is attempting to rehabilitate or prevent injury? It means that your body will try to strengthen itself specifically to the exercises you are doing and that there will be little to no specific strength gained.
Patients always want me to show them exercises that will “strengthen” their muscles to prevent injury. Because of the SAID principle I stay away from showing gimmick exercises and teach patients sport specific exercises that require movements that closely resemble the sport they are participating in. For example; with long distance running we have already established that you need Endurance Strength which equates to doing large volume of repetitions compared to trying to exert Absolute Strength or a one repetition maximum. Our exercises are designed with the specificity of the sport in mind to ensure as much neurological and mechanical strength carryover to the muscles, joints, tendons and ligaments as possible. This means that the more closely an exercise resembles an actual movement the more you will benefit from the rehabilitation or “prehabilitation” exercises. A real world example of this would be a mid or long distance runner doing knee extensions to strengthen their quadriceps. While this will certainly strengthen the Quadriceps it will not provide specific strength and will have almost no carryover strength value to a long distance runner. A far better exercise would be to have the runner do lunges and/or step-up lunges as this exercises more closely mimics the actual mechanics of running and will confer greater specific strength and carryover strength.