The Overlooked Muscles Every Runner Should Train

Whether you're a beginner or an experienced runner, you've likely hit a plateau at some point in your training.

Unclear technique, poor nutrition, or inconsistent workouts are often to blame. But even if you do strength training, are you sure you’re targeting the right muscles? What if we told you that the core unit, pelvic floor, and diaphragm play a critical role in running performance? Let’s take a closer look at these often overlooked muscles.

Don’t Underestimate the Power of Your “Core Belt”

The core unit includes the deep abdominal muscles and the pelvic floor muscles. Commonly referred to as the “core,” this group includes the transverse abdominis and the internal and external obliques.

These muscles handle trunk rotation, provide stability in every plane, and are active in nearly every movement. If you’ve ever felt soreness in this area, you know how essential they are!

In running, efficiency is key—being powerful while using as little energy as possible. Fortunately, the human body is equipped with muscles and ligaments that work like springs: they absorb impact and return energy for forward propulsion. A well-trained core helps optimize this mechanism while minimizing injury risk.

The Popular but Overrated Six-Pack

The rectus abdominis, known as the “six-pack,” lies closer to the surface and mainly serves to flex the trunk (e.g., crunches). Unfortunately, many runners still believe that doing crunches improves performance.

In reality, overtraining this muscle can cause muscular imbalances between the front and back of the body—leading to poor posture and possibly pain.

The Pelvic Floor: Small But Mighty

This muscular “bowl” at the base of your pelvis works in harmony with your deep abdominals and diaphragm to manage pressure and support organs during high-impact activities like running.

Weakness in these muscles can lead to urinary leaks or lower back discomfort. Runners of all genders should be aware of the role the pelvic floor plays in dynamic postural stability and running efficiency.

If you experience symptoms, consult a kinesiologist or healthcare professional for a strengthening program.

Last But Not Least: The Diaphragm

Often considered one of the body’s most important muscles—alongside the heart—the diaphragm is vital for runners. It’s the primary muscle of respiration, and yes, it can be trained!

Improved diaphragmatic control leads to easier breathing and delayed fatigue. In fact, recent studies suggest that respiratory muscles can account for up to 20% of total energy expenditure while running. Imagine the performance boost you could gain by simply improving your breathing mechanics!

Don’t leave these key muscles behind on the starting line!