The plank is an isometric core exercise that builds deep abdominal stability and endurance. Rather than crunching, it trains the core to resist movement — exactly what it does to protect your spine in daily life and heavy lifts.
Muscles worked
Primary: Rectus abdominis, Transverse abdominis.
Secondary: Obliques, Glutes, Shoulders.
Equipment: Bodyweight · Difficulty: Beginner.
How to do the plank
- Set up on your forearms and toes, elbows directly under your shoulders.
- Form a straight line from your head through your hips to your heels.
- Brace your abs as if about to be punched, and squeeze your glutes.
- Keep your neck neutral by looking at the floor just ahead of your hands.
- Hold the position for time, breathing steadily, without letting the hips sag or rise.
Common mistakes to avoid
- Letting the hips sag toward the floor, which stresses the lower back.
- Piking the hips up to make it easier — keep the body in a straight line.
- Holding your breath. Breathe steadily throughout the hold.
Track it automatically with Spotwell
Stop losing count mid-set. Spotwell's AI rep counter uses your iPhone camera to count plank reps automatically — no wearable required — and logs your sets so you can focus on form and progressive overload. See how AI rep counting works →