Injuries are a part of sport and life. It is an unfortunate reality and a lesson some encounter with greater frequency than others. I have had my fair share of injuries as well. The reason why I am writing this post is because of my most recent injury.
Over the past 14 weeks, I have been prepping for a strongman competition in Iowa on May 16. The training cycle had been going smoothly and I was feeling good heading into the final days before my taper. Four days ago, I pulled my left bicep during tire flips. The tire flip is one event that is notorious for causing bicep injuries due to the large amount of mechanical stress it places on the biceps. Fortunately, I did not suffer a complete tear, no surgery needed. However, competing is out of the question. When you are self-employed and your job requires the uses of your hands, there is no need for any further set backs.
For some, injuries mean down time from training. They see injuries as an obstacle. Not in my mind. An obstacle is what you see when you take your eyes off the goal. There are still ways to train around injuries. Sure, I will not be able to do anything stressful with my left arm for 3-6 weeks, but I can still get a powerful training stimulus from a incorporating squat and single-leg variations for lower body strength, jumps/bounds/hops for more intensive CNS stimulus, and training my non-injured arm to help maintain strength and speed recovery of my injured arm.
Wait….what? Training your non-injured arm helps to keep your injured arm strong and heal faster?
There is truth to that statement. The phenomenon I am referring to is known as “cross-education”. It is well established that to minimize the effects of detraining, performing single-side training with the non-injured limb (upper or lower body) will allow you to maintain strength and accelerate healing in the injured limb.
Cross-education occurs when you strength train a limb on one side of the body. The result is an increase in strength in the opposite limb on the other side of the body due to neural adaptations. Cross-education appears to be effective for all muscles and joints of the body, from shoulders and hips to ankles and wrists.
A study published in the Journal of Exercise Science and Fitness demonstrated that strength gains in the untrained limb are typically in the range of 5 – 25% depending on if that limb dominance. Strength gains average around 35 – 60% increase in the trained limb. Additionally, it appears that less range of motion will be lost in the injured limb due to the cross-education effect – another major benefit.
There are other studies on the subject of cross-education, but still cross-education is not completely understood. Strength gains in the injured limb are most likely due to neuromuscular adaptations and increased neural drive to the untrained muscle. A similar hypothesis is improved motor control because training the healthy limb results in recruitment of high-threshold motor units in both limbs. Keep in mind, there is no evidence of hypertrophy (muscle growth) or changes in muscle fiber types in the injured limb following single-side training.
Cross-education highlights the importance of single-limb exercises during training and rehabilitation from injury. Helping clients or athletes understand cross-education may encourage them to continue an exercise routine during time of injury, as it can help maintain strength and speed recovery. Cross-education is a perfect illustration of how one can turn a weakness into a strength through focused training efforts.
Lee, M., Carroll, T. Cross-Education: Possible Mechanisms for the Contralateral Effects of Unilateral Resistance Training. Sports Medicine. 2007. 37(1), 1-14.
Zhou, Shi. Cross-Education and Neuromuscular Adaptations During Early Stage of Strength Training. Journal of Exercise Science and Fitness. 2003. 1(1), 54-60.
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