ichidan verb, intransitive verb
prepare oneself mentally; steel oneself
Rare verb form; the noun 気構え (readiness, mental attitude) is much more common. Used for bracing oneself for a challenge or adopting a determined mindset.
See also: 気構え
彼は試合に臨むにあたって気構えていた。
He had prepared himself mentally for the match.
「気構える」よりも「気構えをする」のほうが自然に聞こえることが多い。
It often sounds more natural to say 気構えをする rather than 気構える.