Planks vs crunches: When to do them

Planks and crunches are two popular exercises to help strengthen the muscles around your midsection. But is one better than the other to help you build a stronger core?

Overall core strength is important for proper posture and balance. If you want six-pack muscles, a strong core is part of the equation.

What muscles do you work?

Both crunches and planks engage the rectus abdominis and the obliques. However, the plank also targets the erector spinae, glutes, hip flexors, quads and deltoids.

Planks

The plank is the best exercise to strengthen the core. It engages the ab muscles, glutes, shoulders, biceps and legs. This isometric exercise is basically a contraction of the muscles of the spine.

It is a bodyweight exercise, which means you use your body weight (instead of other weights like dumbbells or barbells) to build strength.

According to the Centers for Disease Control and Prevention, creating a strong core can help prevent back injuries and improve stability. While you will find people doing both in and out the gym, planks are the gold standard for working your core,

What are the benefits of planks?

Improves posture – Planking strengthens the core and lower back muscles, thereby improving your posture.

Reduces back pain – If you suffer from back pain, planking can be one of the solutions. Since this exercise targets both the core and back muscles, it strengthens them,

Simple and effective – Planks are a full body workout, strengthening muscle throughout your midsection, upper body and lower body. You can hold them for just seconds or longer.

What are the disadvantages of planks?

Tough on wrists – A traditional plank can be tough if you have weak wrists because your body weight is bearing down on your hands and feet.

Plank variations

Basic plank

• Lie facedown in a push-up position with your feet shoulder-width apart and legs fully extended.
• Push your body up and support it on your palms and the balls of your feet.
• Keep your back straight; You should be making a perfect straight line from head to heels.
• Keep the abs engaged by sucking the belly button in.

Tip: Keep your hips squared and in a neutral position, preventing them from dropping down or lifting above the line you create with your body.

Forearm plank

• Lie facedown in a push-up position with your feet shoulder-width apart and legs fully extended.
• Bend you elbows and support your weight on your forearms.
• Lift your hips and balance yourself on your forearms and toes
• Tighten your core.
• You should be making a perfect straight line from head to heels.

Side plank

• Lie on one side with your legs almost straight and your hips, knees and feet stacked.
• Ensure that your elbow is directly under your shoulder, with your forearm flat.
• Push your hand and forearm into the floor to lift your torso. Maintain a tight core and keep your hips lifted, straightening your legs fully. Your body should be close to a straight line.
• Try to hold this position for 20–30 seconds, then switch sides.

Tip: To make it easier, keep your knees touching the floor while you hold the rest of your body up. To modify with knees on the floor, your knees should be bent with your feet pointed back to avoid putting strain on your knees.

Shoulder tap planks

• Start in a basic plank position. Widen your legs for more stability, if needed.
• Keeping your core tight, lift your right hand off the floor and touch your left shoulder. Then, return your right hand to the floor.
• Lift your left hand and touch your right shoulder.
• Continue to alternate hands for 20–30 seconds.

Tip: Don’t let your hips sway from side to side during this movement. The goal is to keep your body in a straight line.

Planks with leg lifts

• Sit tall on the floor with your legs extended in front of you. Place your hands behind you on the floor, with your fingertips pointed toward your body.
• Engage your glutes and core to lift your hips as high as you can, forming a straight line from heels to shoulders.
• Avoid dipping your hips by slightly tucking your pelvis.
• Hold this for 20–30 seconds, or as long as you can while maintaining proper form.

Try this 5 exercise plank workout

Put it all together with a plank workout (video available).

Crunches

Crunches are a classic core exercise that’s great for building your entire core and defining your ab muscles. The crunch is a dynamic movement with a spinal flexion.

There are different variations – each designed to target different areas of your abs.

What are the benefits of crunches?

No equipment needed – You do not need any equipment. A yoga mat can be help but not necessary.

Improve core strength – Improving your core muscles can help reduce lower back pain.

What are the disadvantages of crunches?

Can cause injury – Crunches can place pressure when flexing your spine especially if you already have lower back issues or pain.

Crunch variations

Traditional crunches

• Lie on the floor facing up with your knees bent.
• Put your hands behind your head with your fingers lightly touching your head. Keep from interlacing your fingers.
• Lift your head, neck, shoulders and chest up by pulling from your abs.
• Your shoulders should be off the floor after crunching up.
• Return to the starting position and repeat

Bicycle crunch

• Lie on your back with fingertips behind your ears and elbow out wide.
• Squeeze your abs and bring both legs bent to 90 degrees in a tabletop position.
• Bring your right knee toward your chest and at the same time lift your shoulder blades off the ground, twisting your torso so your left elbow touches your right knee. At the same time stretch your left leg keeping it off the floor.
• Change sides keeping your elbows wide.
• Repeat.

Vertical leg crunch

• Lie face up with your lower back pressed into the floor.
• Place hands behind your head.
• Extend legs straight up, crossed at ankles with a slight bend in knees.
• Contract abdominal muscles by lifting torso toward knees.
• Make sure to keep chin off your chest with each contraction.
• Exhale as you contract upward, and inhale as you return to the starting position.

Scissor crunch

• Lie faceup with legs extended, feet together and hands behind head with elbows wide.
• Raise right foot straight up toward the ceiling, keeping left leg extended and left foot a few inches off the floor.
• Perform a standard crunch, then lower your upper body to about an inch from the floor and switch legs.

Technique tips: what to watch out for

• During crunches, it can be tempting to place your hands behind your head. As a result, you can pull forward on your head. Avoid poor form by touching your fingertips to your forehead. You should also always keep your chin tucked.

Wrap up

The plank strengthens your abdominal and lower back muscles as well as your upper back and shoulders. Core exercises also activate muscles in your pelvis, hips, and abdomen, and demand that all your muscles work in harmony. 

Many experts now recommend planking rather than crunches or situps, since planks put less strain on your spine and hip flexors.