The “core” refers to the main muscles in the trunk of the body. They help protect the spine, provide stability, and increase strength.

Strengthening the core muscles can improve athletic performance, help prevent injuries, and improve posture.

Having a strong, well-trained core can also help create an athletic-looking physique if a person combines a focus on these muscles with a healthful diet and lifestyle that includes other forms of exercise.

This article looks at the benefits of core training and the most effective exercises — for beginners and people with more experience.

a woman performs one of the core exercises known as the plank in a public parkShare on Pinterest
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The following are the core muscles, located in the body’s trunk:

  • Rectus abdominis: Also known as the “six pack,” this helps the body bend forward.
  • Internal and external obliques: Located at the sides of the core, these muscles help the trunk rotate and bend to the sides.
  • Transversus abdominis: This helps stabilize the pelvis during movement.
  • Lumbar multifidus: This back muscle helps support the spine during movement.
  • Erector spinae: This group of muscles and tendons works to straighten the trunk after bending and support the body during lifting.

According to Harvard Medical School, strengthening the core muscles can help:

  • improve balance, stability, and flexibility
  • prevent falls and injuries
  • reduce back pain
  • improve posture

Having a routine that includes some of the following exercises may help strengthen and stabilize the core and improve mobility.

The American Council on Exercise (ACE) recommend starting with exercises that help build core stability before moving onto those that improve mobility, such as exercises called mountain climbers.

Below, we list ACE-approved core exercises, starting with those for beginners. We also give tips to make these exercises more challenging.

1. The bridge

This also helps strengthen muscles in the lower back, hips, and buttocks. The muscles of the buttocks are called the gluteal muscles, or “glutes.”

To perform the bridge:

  • Lie on a mat, with the knees bent and the feet hip-width apart, firmly planted on the floor. The hands should be palm-down at the sides.
  • Squeeze the glutes and lift the hips until there is a straight diagonal line from the knees to the shoulders.
  • Hold this position for 20–30 seconds before slowly lowering the body to the floor. Do this one vertebra at a time, starting at the shoulders and ending at the pelvis.

Intermediate: While lifting the hips, raise the right foot off the floor until the knee is at a 90-degree angle from the hip. Alternate legs for 20 repetitions.

Advanced: Use a resistance band around the hips, securing the band to the floor with your hands. This will make the muscles work harder.

2. Toe taps

These help engage the core muscles while strengthening the glutes, hips, and legs.

To perform toe taps:

  • Lie on the floor, with the feet raised and the knees bent at 90 degrees. Place the hands at the sides of the body with the palms facing down.
  • Lower each foot in turn, lightly tapping the floor, before raising it to the starting position.
  • While doing this, it may help imagine a thread pulling the belly button down into the floor. The aim is to keep the spine stable and prevent the lower back from arching.
  • Perform 2 sets of 8 or 3 sets of 12, depending on the level of fitness.

3. The high plank

This strengthens the abdominal muscles, shoulders, back, glutes, and legs.

To perform the high plank:

  • Start off on all fours, with the hands shoulder-width apart and the feet hip-width apart.
  • Extend the legs behind the body, until the body’s weight rests on the hands and the balls of the feet.
  • Pull in the belly button to keep the core muscles active.
  • Hold this position for 20 seconds while breathing deeply and looking directly at the floor, then return to the starting position.
  • Perform 8 repetitions per set for 2 sets.

Intermediate (elbow plank): Instead of resting the weight on the hands, lower the forearms to the floor so that the arms form a right angle to the floor. Move the feet closer to the body. Hold the position for 30 seconds. Repeat 3 sets of 12.

Advanced (side plank): Lie on one side, with the elbow directly beneath the shoulder and the forearm flat against the floor. The legs should be slightly bent.

Using the oblique muscles, lift the hips to form a straight line, with one leg balanced atop the other. Raise the free arm straight up in the air, holding the position for as long as possible without losing balance — at least 30 seconds. Repeat 3 sets of 12.

4. Bird dog

This exercise strengthens the abdominal and back muscles by challenging stability.

To perform the bird dog:

  • Begin on all fours, with the hands shoulder-width apart and the knees hip-width apart.
  • Tighten the core and extend the right leg behind the body until it is level with the hip.
  • Extend the left arm forward until it is level with the shoulder, keeping the thumb facing upward.
  • Hold this position for 20 seconds.
  • Perform 2 sets of 8 repetitions, alternating with the left leg and right arm.

Intermediate: Once in position, with the right leg and left arm extended, draw these limbs in beneath the abdomen until they are as close to each other as possible. Then extend them to the starting position. Hold this for 30 seconds. Perform 12 repetitions per set for up to 3 sets.

Advanced: Use a resistance band around the feet to work the glutes harder.

5. Abdominal crunches

These help strengthen the core, lower back muscles, and obliques.

To perform abdominal crunches:

  • Lie face-up on a mat, and bend the knees until the feet are roughly 12–18 inches from the tailbone.
  • Place the hands behind the head, and exhale while slowly curling the torso toward the thighs. Continue until the upper back lifts from the floor.
  • Hold this position for a few seconds.
  • Lower the torso slowly to the floor.
  • Beginners should aim for 2 sets of 8 repetitions. Others should aim for 3 sets of 12.

Intermediate: Begin in the same position, but instead of keeping the feet flat on the floor, raise them toward the chest while curling the torso toward the thighs.

Advanced: Hold a weighted medicine ball to the chest while curling the torso upward. Swivel left and right, bringing the ball across the body, before returning to the starting position.

6. Bicycle crunches

This is one of the most effective intermediate exercises for strengthening the rectus abdominis, also known as the six-pack.

To perform bicycle crunches:

  • Lie on a mat with the knees bent and the hands behind the head.
  • Lift both feet.
  • Bring the right knee toward the chest while straightening the left leg.
  • At the same time, lift the shoulders and upper back, bringing the left elbow toward the right knee. Try to touch the elbow to the knee and hold this position for a few seconds before returning to the starting position.
  • Repeat, this time bringing the right elbow toward the left knee.
  • Repeat as often as the fitness level allows.

7. Warrior crunches

These work the abdominal muscles, glutes, thighs, and quads.

To perform warrior crunches:

  • Stand with the feet slightly farther than hip-width apart and the toes pointed outward.
  • Place the hands behind the head and squat as far as is comfortable.
  • Bend the upper body to one side, and return to the center.
  • Repeat on the opposite side. Try not to lean forward or backward while bending. It may help to imagine the body between two panes of glass.
  • Aim for 2 sets of 8 repetitions or 3 sets of 12 repetitions, depending on fitness levels.

8. Mountain climbers

This exercise strengthens the abdominal muscles as well as the shoulders, hips, hamstrings, and triceps.

To perform mountain climbers:

  • Start in a high plank position.
  • Keeping the abdominal muscles tight, bring the right knee to the chest.
  • Return the right leg to the starting position. Bring the left knee to the chest.
  • Start slowly, working up to a faster rhythm. The aim is to alternate legs in one fluid movement.
  • Begin with 2 sets of 8, working up to 3 sets of 12.

The core muscles help protect the spine, stabilize the body, improve posture and balance, and increase strength.

Working these muscles through resistance-based exercise can also help improve mobility.