The most common and most likely answer to this crossword clue is the 8 letter word WARM-UPS
W
A
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Buddy explains!

The straight part
We know that "preparatory activities" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case preparatory activities = warm-ups.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
Crossword Answer definitions
WARM-UPS noun- The act of exercising or stretching in preparation for strenuous activity
- Any act of preparation for a performance
- A period of time allocated for performing warm-ups.