Crossword Genius

Health tracker's introduction welcomed by Polish, but not English (7)

Ross

I believe the answer is:

fitness

'health' is the definition.
(I've seen this before)

I don't understand the rest of the clue.

(Other definitions for fitness that I've seen before include "Well-being" , "Suitability - health" , "condition" , "State of good health" , "Competence" .)

I've seen this clue in The Independent.
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