high school preparation affects college performance in hard courses?

<p>I want to take challenging courses in college (for just for the challenge, but also for my own interest), but I'm afraid I might not be able to handle them given my okayish high school prep. So are most people who work at IB from top high schools, since in order to take challenging courses you would need the AP credit and preparation? epecially hard classes at places like HYPMS.
When IB recruiters say they are looking for a "challenging transcript", does that mean taking hard classes in your major or hard classes in all your subjects?</p>

<p>thank you</p>