Follow legal case that's put on for training purposes (9)
I believe the answer is:
'for training purposes' is the definition.
I can't judge whether this definition defines the answer.
'follow legal case that's put on' is the wordplay.
'follow' becomes 'track' (I've seen this before).
'legal case' becomes 'suit'.
'that's put on' is a charade indicator (letters next to each other).
Can you help me to learn more?
(Other definitions for tracksuit that I've seen before include "Warm loose-fitting garment for exercising", "Sportswear", "it's assumed, if exercising", "athletic gear", "Kit".)