Participants' stamina dire at lowest point (5)
I believe the answer is:
nadir
'lowest point' is the definition.
(I've seen this in another clue)
'participants' stamina dire' is the wordplay.
'NADIR' is hidden in amongst the letters.
But, I'm not sure how the hidden word is indicated.
'at' acts as a link.
Can you help me to learn more?
(Other definitions for nadir that I've seen before include "most unsuccessful point" , "It's the depths" , "Given lowest place" , "All-time low" , "businessman formerly escaping justice" .)