Plank Jack

Plank Jack Exercise Description

Plank Jack is a high-plank variation that layers quick lower‑body movement onto a stable trunk. The goal is to maintain a neutral spine and quiet pelvis while the feet hop in and out, training anti‑extension and anti‑rotation control. Primary contributors include the rectus abdominis, transverse abdominis, and internal/external obliques; the serratus anterior and rotator cuff stabilize the shoulder girdle as you “press the floor away.” The gluteus medius/minimus help keep the pelvis level, while quadriceps and calves support the hops. Because the feet move rhythmically, this drill also elevates heart rate without leaving the plank position. Choose a controlled pace that lets you keep alignment; if needed, use a step‑out version to reduce impact while preserving core engagement.

Muscle Groups: Abs, Core, Obliques, Waist
Target Muscles: External Obliques, Rectus Abdominis
Assisting Muscles: Internal Obliques, Transversus Abdominis
Stabilizing Muscles: Gluteus Medius, Gluteus Minimus, Infraspinatus, Serratus Anterior, Subscapularis
Body Area: Upper Body
Body Parts: Core, Torso
Body Surface: Front, Side
Body Symmetry: Bilateral
Equipment: Bodyweight
Exercise Patterns: Other
Exercise Type: Strength
Functional Grouping: Trunk Flexors, Trunk Lateral Flexors, Trunk Rotators
Joint Involvement: Multi-joint
Muscle Location: Side Abs, Stomach
Movement Direction: Lateral
Muscle Position: Anterior, Lateral
Gender: Male

How To Do The Plank Jack Exercise

‘- Start in a high plank: hands under shoulders, fingers spread, grip the floor.
– Actively press the floor away to protract the shoulder blades; keep neck long and eyes down.
– Align ribs over pelvis, brace the midsection, and keep a neutral spine.
– Bring feet together on the balls of your feet; squeeze glutes lightly and keep legs straight.
– Hop both feet out to hip‑ to shoulder‑width, landing softly; keep hips level and square.
– Hop feet back together under control with minimal torso sway.
– Maintain elbows extended but not locked; avoid shrugging.
– Breathe steadily—no breath holding.
– Use a step‑out/in (one foot at a time) if impact or stability becomes challenging.
– Stop the set if hips pike or sag, the low back arches, or shoulders collapse.

Plank Jack Tips

‘- Place hands directly under shoulders, spread your fingers, and grip the floor.
– Actively press the floor away to protract your shoulder blades.
– Keep your neck long with eyes down toward the floor.
– Align ribs over pelvis, brace your midsection, and maintain a neutral spine.
– Start with feet together on the balls of your feet, legs straight, and glutes lightly squeezed.
– As you hop out, move both feet to hip‑ to shoulder‑width and land softly.
– Keep hips level and square as the feet hop in and out, minimizing torso sway.
– Maintain elbows extended but not locked, and avoid shrugging.
– Breathe steadily throughout the set and avoid holding your breath.
– Use a step‑out/step‑in pattern if impact or stability becomes challenging.
– Stop the set if your hips pike or sag, your low back arches, or your shoulders collapse.

Plank Jack Beginner Introduction

Plank Jack blends a straight‑arm plank with quick, rhythmic leg movement for a mix of core strength and light cardio. The body stays in a long, aligned position while the feet spring apart and together, so the middle of the body works hard to resist arching, sagging, or twisting. The abs, deep abs, and side abs handle most of this effort, while the muscles around the rib cage and shoulders create a solid base through the arms.

Because the legs are jumping, the heart rate naturally rises, turning a static plank idea into a more dynamic drill. The glutes at the sides of the hips help the pelvis stay level, and the thighs and calves contribute to each jump or step. A version that alternates stepping the feet out and in, one side at a time, offers a lower‑impact pattern with the same midsection challenge. Overall, this exercise highlights control, stability, and consistent breathing while the lower body moves quickly.