The phrase "apply that understanding" is correct and usable in written English.
You can use it when discussing the implementation of knowledge or insights gained from a particular context or situation.
Example: "After studying the theory, it's important to apply that understanding to real-world scenarios to see its practical implications."
Alternatives: "utilize that knowledge" or "put that insight into practice".
It also helps to understand how networks work and apply that understanding to analyzing the relationships in your network, using social network analysis tools.
Students learn to understand the complete drug discovery and development process and how to apply that understanding to everyday work experiences to be competitive in today's marketplace.
They may seek to understand how decisions are (or should be) made--or they may apply that understanding to any of a wide range of real-world problems--in business, government, the environment, national defense, and so on.
This result leads one to conclude that while a teacher may have an adequate understanding of the mechanisms of evolution, they may not apply that understanding in all situations.
Maybe I'd be able to apply that understanding to some grand larcenous scheme, live out my days in Fiji.
Human needs and behavior play a special role in life sciences at this level, because children can most easily relate to their own experiences and apply that understanding to how other organisms function.
In order to apply that general understanding to particular cases, we must acquire, through proper upbringing and habits, the ability to see, on each occasion, which course of action is best supported by reasons.
To apply this understanding over the large spatial and temporal scales that are relevant to evolving landscapes, we develop a simple model that tracks porosity changes.
It's important to point out that understanding and applying the techniques from the happiness research doesn't mean that people will be happy all of the time, more that they afford us the opportunity to be happier on a more regular basis.
His contributions extended far beyond the understanding of economic theory and urged a generation to apply this understanding to the betterment of society.
Now we must apply this understanding to people.
