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Plank in and Out

The plank in-and-out starts from a high plank and has you step or hop both feet toward your hands and back out again, blending trunk bracing with hip-flexor work and a rising heart rate. It suits circuit training and home workouts where one move needs to tax the core and conditioning at the same time. Coached by Maddy (NASM-CPT) — these are the exact form cues he gives on every client's first week.

Muscles worked

Abs · rectus abdominis Hip flexors · iliopsoas Obliques Deep core · transverse abdominis

Sets & reps by goal

Goal	Sets × Reps	Rest
Strength	4 sets x 4-6 explosive, perfectly landed reps	2 min
Muscle	3 sets x 9-12 reps	60-90 sec
Endurance	2-3 sets x 18-27 reps or 30-40 sec continuous	30-45 sec

Level — Beginner

Beginner-to-intermediate — the stepping version is accessible to most; the two-foot hop version adds impact and pace.

Proper form — 5 cues

Begin in a high plank with hands stacked under shoulders and fingers spread.
Drive both knees toward your chest, landing the feet softly beneath your hips.
Keep your hands planted and shoulders over the wrists as the feet travel.
Send the feet straight back to the start, finishing in a full, rigid plank line.
Land quietly every rep — the balls of the feet touch first, never a flat slap.

Breathing: Exhale as the feet jump in, inhale as they travel back to the plank — one full breath per rep.

The 3 mistakes Maddy corrects most

Hips shoot toward the ceiling as the feet jump in.. Piking steals the range from the hip flexors and abs, turning the drill into a bounce between two easy positions. Fix: Aim the knees at your chest rather than your hands, keeping the hips lower than the shoulders at the top of the jump.

The plank line never re-forms between reps.. Rushing means the body stays in a half-bent shape, so the trunk never re-loads and the reps stop counting for much. Fix: Pause for a full beat in the extended plank each rep — brace, check the line, then jump in again.

Landing heavily on flat feet with locked knees.. Hard landings jar the knees and wrists and are the first sign the pace has outrun your control. Fix: Slow the tempo, land on the balls of the feet with soft knees, and switch to stepping one foot at a time if the hop stays noisy.

Common questions

Can beginners do plank in-and-outs?

Yes, with the stepping version: instead of hopping both feet, step one foot in, then the other, and reverse. This halves the impact and lets you groove the plank-to-tuck pattern under control. Once you can do 12 smooth stepping reps with level hips, introduce the two-foot hop for a few reps at a time.

Plank in-and-out vs mountain climbers — what is the difference?

Mountain climbers move one leg at a time in a running rhythm, so the trunk deals with alternating, rotational forces at speed. The in-and-out moves both feet together, which demands a bigger single hip-flexion effort and a stronger re-brace in the extended position each rep. Climbers bias speed and conditioning; in-and-outs bias the tuck strength and the plank reset.

How many plank in-and-outs should I do in a workout?

In a circuit, 30 to 40 seconds of continuous work per round for three or four rounds is plenty for most people. If you are counting reps, sets of 9 to 12 crisp repetitions with a genuine plank pause each time hold their quality better than big sloppy sets. Stop the set once landings get loud or the hips start piking.

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