Which are best for your core – planks or crunches? This is a question asked a lot and for good reason. Both exercises work muscles in the core, but one is a clear winner when it comes to building a solid core. But first, let’s take a look at each one separately.
When people think of crunches, they think of building a strong six-pack … and it will do that (provided your body fat percentage is low enough for them to show through). But doing crunches the normal way involves placing excess pressure on the weakest part of your back … the lower part, by flexing it forward.
A better style of crunch is with your spine straight (neutral) instead of bent forward (flexed). According to how the spine is built, it was never meant to be flexed, but kept in the neutral straight position. So the next time you do crunches, do them with your back straight from your shoulder to your butt.
Planks on the other hand are meant to be done with the spine in the neutral position. Because planks are an isometric exercise where the angle of the joint does not change appreciably, they work most of the the heavy hitters of the core muscles – abs, obliques and erector spinea. However, some other secondary core muscles are also worked including the deltoids, trapezius, rhomboids, in addition to the glutes and hamstrings.
By contracting your ab muscles, which draws them closer to your spine, you develop the abs, but you are also developing muscles that support your spine. So not only do you end up with a nice six-pack, but an overall better developed physique to frame your six-pack.
So to answer the question “Which is best for your core, crunches or planks?” planks win hands down. And the two main reasons are because they keep your spine straight and work more of the muscles that make up your core. Crunches will help develop the front of your core – the abs – but often at the expense of spine instability due to the flexing.
When planking, keep these tips in mind:
• Keep your shoulders directly above your elbows when front planking
• Keep your hips in a straight line with your shoulders once in place
• Pull in your glutes and quadriceps
• Keep your hips high during the side plank to work the external obliques
If you have always done crunches, try planks instead and notice how your body responds.