较劲 (較勁) jiào​jìn
clash verb
to set oneself against someone or to be deliberately difficult and disobliging

I don't know why he's always picking a fight with me and making things difficult for me.

compete verb
to match one's strength with others or to be in competition

These two companies have been secretly competing for market share.

exert effort verb
to make a special effort or put extra strength into a task

He was exerting all his strength to move the heavy rock.