July 24 To Your Health column: Separating myth from facts when it comes to core strength
Much confusion exists on the science of good trunk fitness
Dear Colin: My trainer tells me that a strong core is necessary for great abs and to protect my back. Do you agree? What is the core? Im confused and I think my trainer is too as he cant give me a concrete answer. Kevin P.
The term core has been used in fitness for years and refers to trunk muscles. Unfortunately, many claims made by the core strength movement contradict science and research. Let me shed light on this by explaining three relevant principles.
Strength vs. endurance. Strength is the maximum tension a muscle can generate, while endurance reflects a muscles ability to sustain contraction for an extended period. To build strength, you must exercise at high intensity so you fatigue rapidly; to build endurance, exercise at low intensity for a long time. For example, performing a set of 10 repetitions where on the 10th you think you cant continue would build strength; walking for 40 minutes instead of your usual 30 would build endurance.
Spinal stabilizer vs. motion producer. The muscles primarily responsible for stabilizing your spine, the multifidii muscles, are small and composed of fibers made for endurance, not strength. Research shows stabilizing the spine requires coordination and endurance (not strength), so the term core strength is really a misnomer. To use the multifidii muscles, pull your belly in away from your beltline while keeping your pelvis still.
Muscles that produce trunk motion are the rectus abdominis (your six-pack muscles), obliques (sides of your belly) and erector spinae (your low/mid-back muscles). These muscles do not stabilize the spine; they flex, rotate and extend your trunk.
Use of muscles during exercise. Proper technique while exercising large muscle groups (chest, back, legs) simultaneously trains trunk muscles and burns more calories per time unit. This is important because effective exercise doesnt just enhance spinal stability; it fights fat, too.
For basic fitness goals, perform a couple of trunk exercises at home. If youre involved in sports-specific training for repetitive, high-speed trunk motions (such as golf and tennis), you may need more trunk training, but not much more as the majority of strength requirements for virtually all sports lie in the legs.
And dismiss the infamous myth that training your trunk area will make it look better. A great-looking midsection comes from having low body fat, not special abdominal exercises, so watch your diet and exercise daily. Remember that trunk exercises burn very few calories, so dont waste much time on them. How few? An Oregon State University study showed that it would take 27.4 years to burn a pound of fat doing 100 sit-ups per day!
So if you want to maximize exercise results while creating spinal protection, aggressively strengthen the major muscle groups along with the gluteus medius (on the side of your hips) and biceps/triceps (upper arm) muscles while keeping your belly drawn in and pelvis still (this is difficult to do). By doing so, you will burn more body fat while creating a safe haven for your spine.
Colin Hoobler is a licensed physical therapist, hosts a live health segment on KGW Channel 8 and has written two books on exercise as treatment for disease and injury