Times Cryptic No 29093 — A marathon, not a sprint?

43:39. Well, that’s how I felt solving this puzzle anyway. Don’t get me wrong, there were a lot of absolutely delightful clues here (meaning surface reading, wordplay, word choice, etc), but I felt that a fair amount of the difficulty for me stemmed from using very uncommon synonyms or abbreviations. But let me parse the clues and I’ll get back to you.