Are Sit Ups Causing Your Lower Back Pain? Why the Army, Navy & Marines Are Ditching Sit Ups
Are Sit Ups Bad For Your Back?
The US Army recently nixed sit ups when they updated their physical readiness tests, and the Navy and Marines are set to do the same this summer. They’re all finally following what fitness researchers (and your chiropractor) have been saying for years: sit ups, V-ups, and the like are all awful for low back pain, and there are vastly better ways to condition and strengthen your core.
So what’s so bad about sit ups that are causing military institutions to give up on one of the long-time staples of their physical fitness routines?
Sit ups vs. crunches
The sit up had long been the gold standard for improving ab strength, slimming waistlines and revealing the elusive six-pack. Then came the crunch, which unseated the sit up as the go-to ab exercise. Crunches give more focus to the rectus abdominus muscles, unlike sit ups which tend to put too much emphasis on the hip flexor muscles.
The transition from sit ups to crunches was a positive move, but crunches were quickly supplanted by static planks.
The plank
There are lots of variations on the plank, but the basic form is in prone position with forearms and toes on the floor, and hips up in a neutral position. In other words, your body is held straight like a plank for 20-60 seconds at a time. It’s what is referred to as an isometric exercise – muscles are contracted without any actual movement happening.
Planks are great not just for abdominal strength but total core strength. Your obliques, gluteus, and hamstrings are all used while planking, even your shoulders and arms are involved to some extent.
Sure, they look easy (and maybe boring), but staying still and as stiff as a board while on your elbows and toes is a lot more difficult than it looks.
So why are planks better than sit ups and crunches?
The military is switching to planks because they’re coming to realize what experts have been preaching for years: they beat sit-ups in pretty much every way.
Planks have been proven both in the gym as well as in the laboratory to be the most effective way to:
- Activate the abdominal and core muscles
- Support proper posture
- Encourage proper alignment of the spine and pelvis
Planks target the abdominals in the manner in which they are intended to work: isometrically. The main function of the abs is to stop, not start motion. The plank came out of what the abs are asked to do, which is resist the spine from moving, such as when fighting off an opponent or stabilizing the lower back during a run.
Plus, muscle activation during a plank has been shown to be almost twice as active as in a standard sit-up.
Can you do both?
So do you really have to totally give up sit ups and crunches? Can’t you incorporate them alongside planks for a complete workout?
The truth is that not only are sit ups significantly less beneficial than the plank; they’re actually dangerous. If you’ve ever felt lower back pain and strain during a sit-up, you know this already. In fact, one study actually found that 56% of all soldiers’ injuries caused by the old physical readiness test administered by the Army were directly due to sit-ups.
With a sit-up, and to lesser extent crunches, the position and movement of the body works against the natural curvature of the spine, putting extreme compression on the discs in the lower spine. The U.S. National Institute of Occupational Safety and Health sets the safe limit for low back compression at 3300N. Repetitive loading above this level is linked with significantly higher rates of low back injuries in workers. Every single sit up repetition produces compression forces of around 3400N on the lumbar spine.
Additionally, as mentioned earlier, sit ups tend to activate the hip flexor muscles instead of isolating the abdominals. Tight hip flexors “tug” on the lower back and pelvis, leading to anterior pelvic tilt and low back pain.
The Bottom Line
The plank is the most effective, most efficient, and most importantly, the safest core strengthening and stabilizing exercise.
Planks, if done correctly, are safe and put no unnecessary strain or compression on the spine. Variations of the plank movement can be performed to increase or decrease difficulty and target different muscles.
So if you haven’t done so already, it’s time to ditch the sit-up. Stick with planks for the best all-around core and ab strengthening workout.
Brookfield Chiropractor
Whether you’re a pro athlete, weekend warrior or just looking to tone up, study after study shows that regular chiropractic care is an essential part of reaching your full potential. Ready to get stronger? To make an appointment at Ascent Chiropractic, call 262-345-4166 or schedule an appointment with our online scheduling app.
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