My most favorite group of muscles is the abdominals. Always has been and always will be. A strong core is so important. It is great for your posture and your overall well being, it also looks amazing too.
Always remember abs are trained in the gym, but will be revealed in the kitchen. No matter how hard you train your abs, if you don't clean up your mess in the kitchen ( in your gut) nothing will help them make an appearance.
If able to complete the circuit 3x.