Get access to everything we publish when you sign up for Outside+.
You have probably been told that in order to get abs, you need to do strength and core work. What you may not know is how cardio can also help work your abdominal muscles.
Abdominal Muscles Worked During Cardio
There are four types of abdominal muscles: the rectus abdominis (the 6-pack muscle), the internal obliques (inner sides), external obliques (outer sides) and the transverse abdominis (the deepest of the four muscles which runs around the abdominal region like a corset). All four muscles need to be worked in order to reach peak abdominal strength; however, cardiovascular exercise is needed on top of that to see ultimate ab definition.
“Typically, all four [types] activate during running as your arm and leg movement promote some rotation (will fire the obliques) and the impact force of running will fire the transverse abdominis and rectus abdominis to help stabilize the lumbar spine and reduce compressive forces in the spine,” explains NYC physical therapist, Dr. Karena Wu, owner of ActiveCare Physical Therapy. “With the very typical slouched posture, especially after a hard run, the rectus abdominis is kept in a shortened position so it’s not as necessary to contract that muscle. This muscle is a primary mover that controls trunk motion so it is also typically overworked. It is best to emphasize the transverse abdominis to help offset lumbar instability, and then the obliques.”
According to Dr. Wu and her colleague, NYC orthopedist Dr. David Neuman, Founder of Pop-Doc, in order to strengthen the core even more while running, hold your belly button into your spine, without holding your breath. This will keep the core tighter and power up the limbs. It will also give you that nice side definition on your abdominals.
How To Avoid Injury
You can, in fact, injure your abdominal muscles. “Any workout that causes muscle fatigue and overuse is injuring the ‘painful’, sore muscle—but, this is not a detrimental injury,” explains Dr. Neuman. “Actually, with proper hydration and nutrition, the healing muscles, as they repair themselves after a workout, can grow bigger in size and quantity.”
This definitely doesn’t mean to overwork your muscles in order to get bigger and better results, however. That can lead to long-term injury and the need for longer breaks from exercise.
So what can you do should you feel any soreness coming on? Stretch, of course. “Stretch in the opposite direction of the contraction (and the poor posture),” adds Dr. Wu. “This means stretch with your arms reaching long overhead and gently bending backward.”
Burn More Fat
Both doctors explains that running is the highest impact sport because there is a period of gait, in which no part of the body is in contact with the ground. After that moment, one foot hits the ground, all muscles contract at the same time, which means all get a little bit of an exercise.
Specifically, all muscles get a strength and endurance workout at the same time. With this, more fat is burned and your abs are able to look defined faster.
You should definitely be strength training and doing core work in addition to the cardio in order to get the best results. Dr. Wu explains that because the four abdominal muscles work in slightly different directions, it is important to do additional abdominal exercises if you truly want that definition.