Therapy thoughts (02/12/25) - ❌ Stop confusing capacity & tolerance!

There are some concepts that get regularly confused in the MSK rehab world, one of the most common being capacity and tolerance!

Firstly, capacity is one of the most ill defined terms going and capacity can literally be used to describe anything. 

For the purpose of this discussion lets use capacity as the ability to generate force, and this fits with actual definition "the amount that something can produce" 

Tolerance is "the amount of something we can withstand", let's say that is also force for the sake of this argument. So how much force before pain and/or injury. 

Where the confusion lies is that the amount of force we can generate is often seen as a proxy for how much we can tolerate. 

This gets applied in the rehab world by thinking that getting stronger, the ability to generate force, will automatically and linearly improve the ability to tolerate force.  

But research helps us understand that those that can generate more force, e.g. stronger, actually get injured more often. This is seen with sprinters, jumpers and generally across sports too.  

So just because you can generate force does not mean you can tolerate those forces, or force in general, they are not simply interchangeable.  

So is there crossover. Of course. How much? We don't really know.  

Think of this example. We could take a power lifter who is obviously very strong. Would they simply be able to go out and tolerate the forces associated with running as much as a seasoned runner who was much less strong?  

We still don't fully understand what mechanisms contribute to increasing tolerance, of tissues or otherwise, and this is something that could be very important!   

Exposure to forces is likely important to build tolerance. But how far removed and how much those forces need to be is always the question. 

And finally, can that be measured through a proxy such as strength or force output!