I doubt it, but doing crunches is not the way to “tone up your gut”, in fact, I know hardcore bodybuilders who compete that do not even do ab exercises (I don’t recommend that, I like having strong core muscles). Its about the calories you are burning. Cardio is OK for burning calories, but if you want a sustained way to keep a gut off, I recommend pumping iron. The more muscle you have, the higher your resting metabolic rate, which means you are burning more calories with more muscle by simply existing. Of course as Ronnie Coleman once said, “Everyone wants to be a bodybuilder, but don’t no one want to lift heavy weights” (or something like that, but you get the point).
Bottom line, you have muscles under your fat, you just have to burn the fat off to see those ab muscles.
My goal is to be the best me, mind, body and soul, PE is part of achieving the best me.