General:
* Challenged: This word is often used to describe someone who enjoys facing difficulties and pushing themselves.
* Ambitious: This word implies a desire for achievement and a willingness to overcome obstacles.
* Driven: This word suggests a strong motivation to succeed and a desire to overcome challenges.
* Adventurous: This word implies a willingness to take risks and try new things.
* Competitive: This word suggests a desire to win and a willingness to compete against others.
More specific:
* Problem-solver: This describes someone who enjoys finding solutions to difficult situations.
* Risk-taker: This describes someone who is willing to take chances and face uncertainty.
* Go-getter: This describes someone who is proactive and determined to succeed.
* Trailblazer: This describes someone who is willing to be the first to try something new and break new ground.
The best word to use will depend on the specific context and the type of challenge the person enjoys.