I've been really working on core strength like crazy lately, and am getting the gut worse too. It looks like all that body fat is getting pushed out by the muscle underneath. This is not unusual- add muscle before you burn off the fat is how it happens. Be patient, and don't freak if the numbers on the scale rise before they start to fall, muscle weighs more than fat.
And spot reducing is a myth. Do that ab work because you need it to ride, but losing the gut is part of a whole body thing. Be Patient.

Lizzy (very pudgy at present)