Lower sec or upper sec?

I'm confused.....I'm doing my lesson plan (badminton) for the next couple of weeks. What I'm confused about is whether to cater the lesson to lower or upper sec? I mean, there's a LOT of difference between lower and upper sec. The fact that I'm shadowing my CT, and he's teaching upper sec classes, I should logically be planning for upper sec students. Then again, my HOD feels that he might assign the lower sec classes to me for me to teach badminton. Hmmm....meaning I have to plan for BOTH lower and upper? Extra work....oh well.

Cherios,
RuDy