Dasher, say, losing energy lapping male jogger? (8)
I believe the answer is:
reminder
'jogger?' is the definition.
(something which jogs one's memory)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for reminder that I've seen before include "Nudge" , "Memory refresher" , "Prompt, memory jog" , "note" , "Aide-mmoire" .)