Your abs don't need much more than a clean diet and a quick beating in the gym from time to time. In fact, carving out a six-pack can be done with the compound moves you're already doing to build your chest, back, shoulders, and legs. These four routines will save time and combine the concept of isolating the abs, and hitting them with big complex moves. Add these routines to your big muscle days.

Chest Day: 5-minute abs circuit

1. Flat Bench Alternating Chest Press x 12 repetitions
2. Hanging Legs Raise x failure
3. Traditional Crunch x 12
4. Plank x 30 seconds

Back Day: 5-minute abs circuit

1. Barbell Deadlift x 10
2. Mountain Climbers x 10 per side
3. Swiss Ball Plank x 30 seconds
4. Bicycle Crunch x 20

Shoulders Day: 5-minute abs circuit

1. Barbell Overhead Press x 10
2. Swiss Ball Pikes x 10
3. Hanging Knee Raise x failure
4. Plank x 30 seconds

Legs Day: 5-Minute abs circuit

1. Barbell Front Squat x 12
2. Plank x 30 seconds
3. Hanging Legs Raise x failure
3. Cable Crunch x 12