Why You Should Just Stop Doing Crunches

Published February 18, 2016 07:15PM

Adapted with permission of VeloPress from Core Envy: A 3-Step Guide to a Strong, Sexy Core by exercise physiologist and personal trainer Allison Westfahl. Learn more at coreenvybook.com.

It might come as a shock that a good core strengthening program should not include crunches!

As an exercise physiologist, I omit crunches from my personal training programs because they don’t utilize a significant percentage of your core musculature.

While it feels like you’re working hard when you’re 70 reps into a grueling round of 100 crunches, you are predominantly working a single muscle group—the rectus abdominis (rectus). In actuality, the true “core” of the body includes countless other muscles. It’s all the core muscles that affect how well you move—and how good you look.

This brings up the issue of function versus vanity. Why wouldn’t you want to focus your gym time on developing a rockin’ rectus? Aren’t those the beach muscles that look great with a spray tan? If a well-developed rectus is what turns heads, do we really need a well-rounded core routine that works all the other muscles?

The short answer is that a high-functioning core leads to a better-looking core.

Focusing on only a few core muscles can lead to poor posture (which makes your tummy stick out) and injuries (which will inhibit you from being able to work out). Build a solid foundation for your core with a well-rounded core routine, and you will accomplish the dual goals of looking good while being strong and pain-free.

When I talk about the foundation for your core, I’m not referring just to the intricate musculature beneath your abs. Your glutes and hamstrings are also involved. These muscles are traditionally categorized as “lower-body” muscles, but they serve a dual function in helping to stabilize and move the pelvis, which makes them part of the core. In fact, any muscle that is attached to either the pelvis or the spine is technically part of the core. Add to the major muscle groups all of the smaller, deeper muscles in this area, and the count of how many muscles are in the human core easily reaches into the hundreds. If your core strengthening routine is based solely on crunches, you’re neglecting 95 percent of your core musculature.

When a large percentage of your core muscles is routinely ignored, it creates a muscular imbalance in which a muscle or group of muscles becomes tight and overactive, therefore causing a neighboring or opposing muscle to become weak and underactive.

Core imbalances are problematic because our muscles control our joints and bones, and when a certain muscle is doing too much work, it will start to pull the bones and joints it is attached to into uncomfortable positions.