Say one was running along the road, and a police officer shouts "Oi". As I understand it you have no legal requirement to engage with them, and can continue your run. This seems to be consistent with the government guidance on being asked to identify yourself:
A police officer might stop you and ask: what your name is, what you’re doing in the area, where you’re going. You don’t have to stop or answer any questions. If you don’t and there’s no other reason to suspect you, then this alone can’t be used as a reason to search or arrest you.
However, if they shout "I am a police officer, you are under arrest for [specific crime], I am arresting you because [why it’s necessary to arrest you] and you are not free to leave" then you are required to stop your run and engage with the police. The same would be true of a stop and search with slightly different things they must say. However, unless they are very good at talking and running by the time they have said all that you are likely to be out of hearing range.
At what point in such an encounter are you required to engage with the police, or at what point does continuing your run become resisting arrest? It was suggested in the comments that the threshold for the police legally using violence could be different than the threshold for criminality, if such is the case that would be a great addition to the answer.
It has been suggested that this question may answer mine. The linked question is about what information you have to provide once you are interacting with the police, my question is about what point you have to interact with police.
