Why Do I Keep Getting Hurt? Load vs. Capacity

After an injury athletes are often left to wonder what went wrong? Some athletes may even have frequent injuries and start to think that the problem is their body or the sport itself.  The thing many people don’t know is that most injuries all boil down to the same thing... Load vs. Capacity. 

Load is the amount of mechanical stress placed on the body.  Capacity is the amount of stress that your body is able to tolerate. Every tissue in the body has a certain capacity.  If the load is much greater than the tissue’s capacity, there is a higher risk of pain or injury.  However, if you gradually build the amount you are loading your body over time, the capacity of your tissues will increase and you will be able to handle more load. Increasing your capacity means that your muscles will become stronger, your tendons will be able to handle more force, and you will overall be able to do more while feeling good.  Your capacity is what you have prepped your body for.  

While many people understand this basic idea of gradually building yourself up so that you can handle more, there is more to the equation that needs to be considered. Your capacity can change based on other factors such as sleep, stress, illness, and more. For example, if you have many nights of poor sleep your capacity is lower. Then when you go for that tough workout and try to beat your lifetime PR, your body may not be able to safely handle the load you use.  Other stressors such as work, school, or crazy family drama can also lower your capacity at that point in time. 

This concept is explained well by the water in the bucket analogy (credit to Greg Lehman).  The bucket represents your capacity.  The water represents all the potential contributors to pain or injury.  You can either make the bucket bigger by building your capacity over time, or you can decrease the water in the bucket.  So think about what’s in your bucket.  Can you improve your stress, sleep, or anxiety?  Have you been over exerting yourself consistently in the gym?

Many people are told their pain is due to biomechanical abnormalities.  Have you ever heard that you are “out of alignment, your glutes aren’t firing, or you’ll never be the same after that herniated disc”?  These claims focusing on problems with how you are built are not supported by research.  If you give the body enough time to adapt, you can decrease injury and pain, even if you don’t move “perfectly.”  Think about the Paralympics.  These incredible athletes often have significant asymmetries, yet they are able to perform at high levels without limitations due to pain or injury. Gradually building capacity and properly managing load is certainly key in keeping these athletes healthy.

Here are a few examples: 

Increased load with the same capacity (i.e. went too heavy in a workout, worked out 7 days this week when you normally do 4)

Same load and decreased capacity (i.e. very little sleep this week, bombed your final exam, family member is sick)

Want to know the secret to avoiding injury?  Gradually expose yourself to load.  Work on managing your stress.  Prioritize good sleep rather than that extra episode of The Office which you’ve already seen 4 times.  Not all injuries are unavoidable, but you can greatly decrease your injury risk if you focus on the relationship between load and capacity.