A well-defined six-pack may be your ultimate fitness goal, but overworking your abdominal muscles can have negative effects on your posture, breathing and spinal health. Learning how to effectively exercise the muscles of your trunk and pelvic floor can save you from back pain and postural problems as you age.
Form and Function
Your abdominal muscles perform the important functions of stabilizing, flexing and rotating your trunk -- and helping you to breathe. The muscles that define your abs are the internal and external obliques, which work like a corset to define your waistline, and the rectus abdominis, the long muscle that runs from your rib cage to your pelvis. The rectus abdominis is dissected vertically by a thin sheath of connective tissue, and trisected horizontally by tendinous attachments, creating the six pack, or washboard look. According to exercise scientist Len Kravitz, Ph.D., many popular abdominal exercises are inadequate and ineffective, doing little to strengthen your abs while setting you up for low back pain.
Ripped or Hipped
Certain abdominal exercises like traditional sit-ups and leg raises rely on your hip flexor muscles as prime movers, with limited involvement of the abdominal muscles. The hip flexors include the rectus femoris of your quadriceps group and the psoas of your pelvic floor, both powerful muscles that draw your legs toward your trunk from the hip. According to Dr. Kravitz, if your abdominal muscles are weaker than your hip flexors, the hip flexors pull on your low back during certain exercises, causing it to arch and placing stress on your lumbar spine; this results in low back pain.
Your rectus abdominis originates at your lower ribs, and your internal and external obliques are attached to your ribs by fanned-out tendons that wrap around your trunk, all the way to your low back. Postural therapist Michaelle Edwards, LMT explains that overworked and tight abdominal muscles can restrict the expansion of your ribcage, inhibiting effective breathing. What's more, tight abs throw your trunk out of alignment, pulling your breastbone toward your pubic bone, and compressing your internal organs. This creates a distorted carriage, with the head and shoulders jutting forward. Over time, this posture can become rigid, resulting in the forward-bent posture associated with old age.
The Core Gives You More
Your abdominal muscles are part of a larger muscle group that stabilizes your trunk and pelvis, often referred to as the core. The "Harvard Medical School Family Health Guide" recommends training your core muscles, including your abdominal muscles, to promote good posture, reduce injury, and improve the effectiveness of your workouts. Exercises that target your core include traditional crunches, planks, supine cycling where you draw your knee to your opposite elbow, and stability ball exercises.