Core workout: six exercises, a 20-minute session and an honest progression

What the core actually does

The core is not one muscle. It is the group that wraps the trunk: the rectus abdominis at the front, the obliques on the sides, the deep transverse abdominis, the muscles along the spine, and the hips and glutes below. Most of the time their job is to stop movement rather than create it. When you carry a suitcase in one hand, the side of the trunk stops you leaning over. When you push a heavy door, the abdomen stops the lower back arching.

That is why a modern core workout mixes three kinds of exercise: anti-extension (the plank, the dead bug), anti-rotation and anti-lateral flexion (the side plank, the carry, the bird dog), and hip extension (the bridge). Sit-ups and crunches are not banned, but they train only one direction of a muscle group built for several.

Trunk endurance can be measured. McGill and colleagues built a set of hold tests for the back extensors, the trunk flexors and the side bridge, which proved highly reliable in young adults, with coefficients above 0.97. Their tests also showed that the balance between the front, the sides and the back varies from person to person, which is a good argument for training all three.

Six exercises, with technique

1. Dead bug. Lie on your back, arms pointing at the ceiling, hips and knees bent at right angles. Press the lower back gently into the floor. Slowly lower one arm and the opposite leg towards the floor, then return. The set ends when the lower back lifts.
2. Bird dog. On hands and knees, hands under shoulders and knees under hips. Reach one arm forward and the opposite leg back until both are level with the trunk, hold for two seconds, return. Keep the hips square, as if a glass of water sat on your lower back.
3. Front plank. Forearms under the shoulders, body in one line from heels to head, abdomen and glutes tight, breathing normally. Our plank exercise guide covers the details and the common faults.
4. Side plank. On one forearm, elbow under the shoulder, hips stacked, body straight. Start from the knees if needed.
5. Glute bridge. On your back, knees bent, feet flat. Push through the heels to lift the hips until the knees, hips and shoulders line up, squeeze the glutes, lower slowly.
6. Suitcase carry. Hold one dumbbell, a kettlebell or a full shopping bag in one hand and walk 20 to 30 metres without leaning. Switch hands.

How hard each exercise should feel

The NHS advises muscle-strengthening work on at least two days a week, for all the major muscle groups including the abdomen, and describes a set as 8 to 12 repetitions taken close to the point where another one would be difficult. For holds, the same idea applies: the set should end when form starts to break, not long before.

For the dead bug, bird dog and bridge, aim for 8 to 12 slow repetitions per side. For the plank and side plank, holds of 20 to 60 seconds are a common coaching range; no study sets an ideal duration. Once a minute feels easy, make the position harder rather than longer. The calculator on this page adds up holds and rests so you can see how long the block really takes.

A 20-minute core session

1. Warm-up, 3 minutes. March on the spot, then ten slow cat-and-camel movements on hands and knees.
2. Dead bug, 3 minutes. 3 sets of 8 per side.
3. Bird dog, 3 minutes. 3 sets of 8 per side, two-second hold at the top.
4. Front plank, 4 minutes. 4 holds of 30 seconds, 30 seconds of rest.
5. Side plank, 4 minutes. 3 holds of 20 seconds on each side.
6. Glute bridge and carry, 3 minutes. 2 sets of 12 bridges, then two carries per hand.

This block also fits at the end of a full-body session, after push-ups or the hip hinge, when the large movements are done.

How to progress over eight weeks

• Weeks 1 and 2: easiest versions. Knee side plank, plank with hands on a bench, dead bug with only the legs moving.
• Weeks 3 and 4: full versions, adding one repetition or five seconds per set each week while the form stays clean.
• Weeks 5 and 6: harder positions. Plank with one foot lifted, side plank with the top leg raised, single-leg bridge.
• Weeks 7 and 8: add load or instability. A heavier carry, a band pulled sideways during a standing hold, dead bug holding a light weight.

An electromyography study by Escamilla and colleagues found the highest abdominal activity in exercises such as the roll-out on an ab wheel, the hanging knee raise and the reverse crunch on an incline. They are good options once the basics are solid, but muscle activity on a sensor says nothing on its own about long-term results.

What core work will not do

It will not flatten the stomach on its own. In Vispute's trial, six weeks of abdominal exercise did not reduce abdominal fat. Fat is lost from the whole body through overall activity, food and sleep, as our guide to losing belly fat explains. The toning principles guide shows what changes how a midsection looks.

It is not a special cure for back pain either. Saragiotto's Cochrane review of 29 trials found that motor control exercise helped chronic low back pain compared with minimal intervention, but was not better than other exercise. A broader 2021 Cochrane review by Hayden and colleagues found that exercise therapy in general reduces chronic low back pain. If your back hurts, read our guide to exercises for back pain first.

If you have back pain that is severe, getting worse or comes with numbness or weakness in the legs, see a doctor before starting core work. Stop any exercise that sharpens the pain, and keep breathing during holds, especially with high blood pressure.

Start your core workout with Never Skip Club

The simplest way to make core work stick is to stop treating it as an extra. In Never Skip Club, you choose the body area, the level (Easy, Medium or Intense), 20, 30 or 45 minutes and where you train, and the app builds a guided session of five or six animated exercises in about a minute, with your sets logged. Set up a crew of three to seven friends with a rhythm such as three sessions a week: the ranking rewards regularity, not extra sessions, so nobody wins by overdoing it. Create your free account, launch your first core session tonight, and if you want an expert to check your plank and your bridge, find a coach from our network. Already a member? Sign in.