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Plank: How to Do It, Muscles Worked and How Long to Hold
By Mike Shilling, Recovery & Training Editor · Updated 8 July 2026
The plank is the simplest core exercise there is, and one of the most misunderstood. You hold your body in a straight line off the floor, braced from your shoulders to your heels, for a set amount of time. There is no movement, which is exactly the point: the plank trains your core to do its most important real-world job, keeping your spine stable while everything around it works. Done well it builds a strong, resilient midsection that protects your back and improves every lift. Done badly, with a sagging hip or a raised backside, it does very little. Here is how to get it right.
How to do a plank
You need nothing but a bit of floor, though a yoga mat makes it comfortable on your forearms and elbows.
- Set your base. Lie face down, then prop yourself on your forearms with your elbows directly under your shoulders. Your forearms can be parallel or your hands clasped together.
- Lift into position. Tuck your toes and lift your body off the floor so you are supported on your forearms and toes only, in a straight line from head to heels.
- Brace hard. Squeeze your glutes, tighten your abs as if bracing for a punch, and gently tuck your pelvis so your lower back is flat, not arched. Push the floor away with your forearms to spread your shoulder blades.
- Set your head and gaze. Keep your neck long and look at the floor just in front of your hands, so your head continues the straight line of your spine.
- Hold and breathe. Hold the brace and keep breathing steadily. Stop the moment your hips start to sag or hike up, because that is the point the exercise stops working.
The test for a perfect plank
Imagine a broomstick laid along your back. It should touch the back of your head, your upper back and your tailbone all at once, with a small gap at your lower back. If your hips sag, the stick lifts off your tailbone; if your backside pokes up, it lifts off your head. Brace your glutes and abs together to keep all three points in contact.
Muscles worked
The plank is an anti-movement exercise: your core works hard to stop your body collapsing, rather than to create movement.
- Rectus abdominis and transverse abdominis. The front and deep abdominal muscles brace to stop your lower back arching, and static planks produce meaningful activation of these muscles (core activation during static planks).
- Obliques. The muscles on the sides of your waist stabilise your torso and resist any twist, and they work even harder in the side plank variation.
- Erector spinae (lower back). These run either side of your spine and work with your abs to hold the neutral position.
- Glutes and quads. Squeezing your glutes and keeping your legs straight stops your hips sagging and turns the plank into a full-body brace.
- Shoulders and serratus. Your shoulders and the muscles around your shoulder blades keep your upper body stable and stop you sinking between your arms.
Because the plank trains these muscles to work together, it transfers directly to compound lifts like the deadlift and goblet squat, where a braced core protects your spine.
How long to hold a plank
Forget the multi-minute record attempts. For building real core strength, quality and tension matter far more than the clock.
- Beginner: 2 to 3 sets of 15 to 20 seconds with perfect form.
- Intermediate: 2 to 3 sets of 30 to 45 seconds.
- Advanced: rather than holding longer than 60 seconds, move to a harder variation, add a weight plate on your back, or introduce movement.
The moment your form breaks (hips dropping or rising) you should stop, rest, and go again. A sagging plank held for two minutes trains bad positioning and can nag at your lower back.
Benefits
- A stronger, more stable core. The plank builds the deep bracing strength that protects your spine during everyday lifting, carrying and bending.
- Better posture and less back ache. A strong core helps you hold a tall, neutral spine, and core strengthening is a standard part of the NHS advice to help manage and prevent back pain.
- Carryover to every big lift. Squats, deadlifts and presses all rely on a braced trunk, so a strong plank makes you stronger elsewhere.
- No kit and little space needed. You can plank anywhere, which makes it ideal for home training, and the NHS recommends muscle-strengthening work on at least two days a week.
Common mistakes
Sagging hips. The most common fault. When your abs tire, your hips drop and your lower back arches, which loads the spine instead of the muscles. Squeeze your glutes and abs harder, and cut the hold short before it happens.
Backside in the air. Hiking your hips up turns the plank into an easy rest position and takes the tension off your core. Lower your hips until your body is a straight line.
Holding your breath. Bracing does not mean freezing your breath. Keep breathing in a steady, shallow rhythm while maintaining the tension.
Head dropping or craning up. Looking forward strains your neck; letting your head hang breaks the line. Keep your neck neutral and your gaze on the floor just ahead.
Chasing time over tension. A loose two minute plank is worse than a rock-solid 30 second one. Maximise the brace, not the clock. Adding an abdominal hollowing cue can increase deep muscle activation without extra time (hollowing and core stability).
Variations
Once a standard plank feels controlled for 45 seconds, progress with these instead of just holding longer.
- Side plank. Balance on one forearm and the side of one foot, body in a straight line, hips lifted. This targets the obliques hard. Hold each side for 20 to 30 seconds.
- Plank with shoulder taps. From a high plank (on your hands), tap the opposite shoulder with each hand without letting your hips rock. This adds an anti-rotation challenge.
- Plank with leg lifts. Lift one straight leg a few inches off the floor and hold, then swap. Raises the demand on your glutes and lower back.
- RKC plank. A short, all-out 10 to 20 second plank where you squeeze your glutes, quads and abs as hard as physically possible. Superb for teaching maximum tension.
- Weighted plank. Have someone place a weight plate on your upper back, or wear a weighted vest, to add resistance once bodyweight holds are easy.
A simple weekly plan
- Days 1 and 3: 3 sets of a front plank at your level, plus 2 sets of side plank each side. Rest 45 to 60 seconds between sets.
- Progress: when you can hold clean form for the top of your range, move to the next variation rather than adding time.
- Pair it up: planks work well at the end of a session alongside compound lifts, or as part of a core circuit with hanging leg raises and hip thrusts.
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Frequently asked questions
What muscles does the plank work?
The plank mainly works your deep core, including the rectus abdominis (the six-pack muscle), the internal and external obliques on your sides, and the transverse abdominis that wraps around your middle. Your lower back, glutes, shoulders and quads all fire to keep your body in a straight line, which makes it a genuine full-body brace rather than just an ab exercise.
How long should I hold a plank?
For most people a strict 20 to 45 second hold is plenty, repeated for 2 to 3 sets. Quality beats duration: a perfectly braced 30 second plank does far more than a sagging two minute one. Once you can hold clean form for 45 to 60 seconds, make it harder with a variation rather than simply holding longer.
Is a longer plank better?
Not really. Beyond about 60 seconds a standard plank becomes an endurance test that adds little for most goals, and form usually breaks down. It is more effective to progress to harder variations, add small movements, or hold a weight on your back than to chase multi-minute holds.
Do planks burn belly fat?
Planks strengthen and tone the muscles under your belly, but they do not burn fat from that specific area. You cannot spot-reduce fat. Losing belly fat comes from an overall calorie deficit through diet and regular activity, with planks helping build the core strength and definition underneath.
Are planks better than sit-ups?
For most people, yes. Planks train your core to resist movement and keep your spine stable, which is what the core does in real life and in most lifts. They are also gentler on the lower back and neck than repeated sit-ups. Sit-ups still have a place, but the plank is a safer, more functional starting point.
How often should I do planks?
Three to four times a week is plenty for steady progress. Your core recovers quickly, so you can train it more often than larger muscle groups, but there is no need to plank every day. Two or three quality sets on a few days a week will build a strong, stable midsection.
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