synthesis

The sentence is correct as far as it goes. Although the two sentences you showed in bold convey the idea that you must jog three times a week to be fit for the match, your sentence is about jogging to avoid being unfit for the match, a subtle difference.

I suggest something like

You must jog at least thrice a week so that you are fit for the match.

"Lest" is rather old fashioned. (So it "thrice"!)