For Abs: Go Hard 'Core'

It’s easy to knock out a few crunches or situps at the end of a workout and believe you’ve worked your core. Wrong! Effective ab work should never be an afterthought. To avoid that, plan your core work on days in between regular lifting. You’ll get better results—an even more shredded torso and core. To avoid over-training, we’ve limited the workouts to three exercises per session. That’s plenty. The moves will challenge your balance and stability and require only 20 minutes.
DIRECTIONS:
FREQUENCY: Perform two core workouts per week for four weeks in between your main workouts.
TIME NEEDED: 20 minutes

The three exercises in each workout will vary. Perform them as a circuit, completing one set for each, one after the other, and resting as little as possible in between. Repeat for the   prescribed number of sets.  To get started Click Here.