Selected RG myths randomly and went for a walk (9,2,4)

I believe the answer is:

stretched my legs

I'm a little stuck... Click here to teach me more about this clue!

'went for a walk' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.

'selected rg myths randomly' is the wordplay.
'randomly' indicates an anagram (I've seen 'roaming randomly' mean this).
'selected'+'rg'+'myths'='selectedrgmyths'
'selectedrgmyths' anagrammed gives 'STRETCHED MY LEGS'.

'and' acts as a link.

Can you help me to learn more?

I've seen this clue in the Sydney Morning Herald.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.