The “Holy Trinity” of Ab Training
Summary
Jeff Cavaliere of ATHLEAN-X presents a three-muscle-group framework for ab training that goes beyond standard crunches. By training the rectus abdominis, obliques, and serratus anterior together in a single session, you can improve both the appearance and performance of your core. All three exercises can be performed on a captain’s chair, dip bars, or even a kitchen counter corner.
Key Points
- Three muscles must work together for a well-defined, high-performing core: the rectus abdominis, the obliques, and the serratus anterior
- These muscle groups are naturally synergistic — the body prefers them to work together, so training them in isolation is suboptimal
- The serratus anterior feeds directly into the obliques; both are diagonally oriented muscles that streamline the overall appearance of the core
- No specialized equipment required — a kitchen counter corner can substitute for a captain’s chair or dip bars
- Shoulder positioning matters from the start: avoid letting shoulders sink down, as maintaining upright position increases serratus activation even during setup
- Spinal flexion, not just leg raises, is the key to properly targeting the rectus abdominis — the bottom half of the body should visibly face the viewer, indicating a tucked, flexed spine
- Scapular protraction (pushing the arm away from the body) is the primary movement that activates the serratus anterior
Exercise Details
1. Hanging Knee Raise with Spinal Flexion (Rectus Abdominis)
- Target muscle: Rectus abdominis
- Proper form cues:
- Hold the bars with shoulders up (not depressed)
- Tuck the pelvis and flex the spine so the bottom half of the body faces forward — “show your ass”
- Focus on spinal flexion, not just lifting the knees
- Common mistakes to avoid:
- Simply raising the knees or toes without flexing the spine
- Letting the shoulders sink down throughout the movement
- Sets/reps: Rep out to failure
2. Hanging Twist (Obliques)
- Target muscle: Obliques
- Proper form cues:
- Start from the locked-in, upright shoulder position
- Twist the lower body across, bringing the legs up and rotating through the torso
- Alternate sides each rep
- Common mistakes to avoid:
- Performing twists without the initial lock-in shoulder position
- Sets/reps: Not specified; both sides trained equally
3. Serratus Push (Serratus Anterior)
- Target muscle: Serratus anterior
- Proper form cues:
- Lean the torso forward on the bars
- Sink down first, then drive the pelvis up and under while pushing the arms away from the body (protraction)
- The “push up and away” motion is what activates the serratus
- Common mistakes to avoid:
- Treating it as a standard dip — the forward lean and protraction are essential
- Sets/reps: Multiple reps shown; specific count not given