The most common and most likely answer to this crossword clue is the 4 plus 1 plus 4 plus 6 letter word TAKE A DEEP BREATH
I've seen this crossword clue in Independent
T
A
K
E
A
D
E
E
P
B
R
E
A
T
H
More clues leading to the result TAKE A DEEP BREATH
Buddy explains!
The straight part
We know that "Pause/to participate in lung capacity test?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case pause/to participate in lung capacity test? = take a deep breath.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.