What does the cryptic crossword clue "Knocking back Castle Cary ale really restricts legs of runners (5,4)" mean?

The definition is "legs of runners". The wordplay uses a hidden word. Backwards hidden in [Castl]E CARY ALE R[eally]. The answer is RELAY RACE.

Knocking back Castle Cary ale really restricts legs of runners (5,4)

Times Cryptic #28639 | 10 Across | 2023-06-26 flower