This ab-focused workout consists of four different exercises, each targeting various muscles within your core for a comprehensive abdominal training session. You'll start with Floor Crunches, a classic core exercise aimed at the rectus abdominis, performing three sets of 15 reps to really engage and work the 'six-pack' muscles. Ensure your movements are slow and controlled, and focus on lifting through your chest rather than pulling your neck.

Next, as you move into Alternate Oblique Crunches, also with three sets of 15 reps, you'll be targeting your oblique muscles on the sides of your abdomen. These are crucial for rotational strength and define your waistline. Make sure to twist through the upper body, not just turning your elbows, to fully activate the obliques.

Following this, Elbow to Knee Side Plank Crunches, done for three sets of 15 reps, will provide a dynamic challenge, engaging not only the obliques but also your deep core stabilizers and shoulder muscles. Keep your hips elevated, and ensure proper alignment from head to heels for maximum benefit.

Finally, the workout concludes with Bottoms Up, which targets the lower abs—a typically hard-to-reach area—for three sets of 15 reps. Remember to press your lower back into the floor and lift your hips using your lower abs, not just swinging your legs, to prevent lower back strain and maximize the effectiveness of the exercise. Between each set, maintain minimal rest to keep the intensity high, and always focus on quality reps over quantity.