Answer:
An action that represents an example of conditioning is running longer distances in preparation for a marathon.
Step-by-step explanation:
Conditioning may be defined as the methodology through which a person or animal is given training or modification in order to behave in a certain way or to accept certain conditions.
According to the context of this question, if you want to run a marathon, prepare yourself according. This is because it is considered one of the toughest and longest-running events which requires sufficient stamina and physical capability.
Therefore, running longer distances in preparation for a marathon is an action that represents an example of conditioning.