GI less sad after training manoeuvres on mountain (9)

I believe the answer is:

glissades

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

'manoeuvres on mountain' is the definition.
The definition and answer can be both acts as well as being plural nouns.
Perhaps there's an association between them I don't understand?

'gi less sad after training' is the wordplay.
'after training' is an anagram indicator (train can mean to shape or control).
'gi'+'less'+'sad'='gilesssad'
'gilesssad' anagrammed gives 'GLISSADES'.

Can you help me to learn more?

I've seen this clue in The Independent.

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.