Runners Do This Before a Race to Elongate Muscles

This page is the CodyCross answer for the clue below from Trip to Spain, Group 856, Puzzle 2 (The White Isle).

Question is: Runners Do This Before a Race to Elongate Muscles

and the answer is: STRETCH

Word Meaning:

STRETCH — (transitive) To lengthen by pulling.

Definitions from Wiktionary.