Crossword Genius

Reckon to keep fit (4,3)

Ross

I believe the answer is:

work out

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

'reckon' is the definition.
(I know that reckon can be written as work out)

I don't understand the rest of the clue.

Can you help me to learn more?

I've seen this clue in The Globe and Mail.
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.