Runners are always told to strengthen their core. It’s good advice, but many people still assume “core” is synonymous with “abs,” implying that whatever tightens your belly will also make you a stronger runner. The truth is that most traditional core exercises (i.e. planks, crunches) don’t translate into the kind of stability needed to fully power your running or protect you from injury.
In fact, core stability starts with a deeper group of muscles often referred to as the “inner core”—the diaphragm, pelvic floor, multifidus, and transversus abdominis (the only ab muscle in the bunch).
Women are more likely to have difficulty activating their inner core muscles, in part because the female pelvic floor is more prone to dysfunction (due to anatomy and poor posture habits or as a result of pregnancy). However, men commonly suffer from a weak core as well because of prolonged sitting and poor posture. If you’re not engaging your inner core, the outer core lacks a firm foundation to function to its fullest, and you’ll lack the stability to power your running. The result? Greater potential for injury and decreased performance.
So how do you ensure your inner core is functioning properly?
1. Drop your ribs.
Neutral posture for running is when your ribcage is positioned directly over your hips. Think "looking over the edge of a cliff" or "going off a ski jump" - you want your chest and head facing straight ahead, with ribs stacked over hips.
2. Untuck your butt.
When you stand with your butt tucked under you, you assume a posterior pelvic tilt. Not only does this limit your ability to utilize your inner core, but also it leads to weak, underused glute muscles. Instead, think "a string attached to your tailbone, pulling it towards the ceiling" while running.
3. Don’t suck in your gut.
When you suck in your stomach, you are unable to breathe with your diaphragm and your pelvic floor muscles can’t relax. Over time, your inner core can become tight, weak and dysfunctional, you will get breathless easily, and never reach your full running capacity.
4. Breathe Right
Inhale using your diaphragm (allowing your rib cage to open to the sides and belly to expand) rather than just breathing using your chest. When you exhale, your pelvic floor and transverse abdominis recoil. This generates deep tension in your torso—good tension that anchors your core and creates stability when you run.