It's hard to find a person who wouldn't like to have a washboard-flat stomach with rippin' abdominal muscles. It also might be hard to find many people whose idea of a good time is doing hundreds of sit-ups.
If you aspire to a flat stomach but don't relish the thought of earning it, you may be pondering just how many sit-ups it will take to do the job. Are 30 sit-ups a day enough to sculpt you into hard-bellied warrior? The answer is: yes, absolutely — so long as you throw in the same number of crunches, leg-lifts, planks and other abdominal exercises.
And don't forget the new dietary regimen to lose the excess belly fat that no amount of exercise is going to melt away. Just as there is no Santa Claus, there is no such thing as spot reduction. So add to all of the above a big helping of cardiovascular activity.
Thirty sit-ups will get you flat abs, as long as you combine them with other exercises like crunches, leg-lifts and planks.
Sit-Up Pros and Cons
Sit-ups have their good points, but they've got their drawbacks too. They work the lower abdomen better than crunches, which work the upper abdomen. They work the hip flexors. That's good as far as it goes.
But sit-ups are notoriously hard on the back. Those hip flexors are some of the strongest muscles in the body, and when they're over-developed to the exclusion of other muscles, the resulting imbalance can cause lower back pain. That's not a problem you encounter so much with crunches.
The fact of the matter is, sit-ups — and to some extent crunches — are no longer considered by many trainers to be the best way to go. (Crunches are basically partial sit-ups, in that the lower back does not leave the ground.)
Better Than Leg Lifts
But it may be too early to discard the sit-up just yet. A study in the February 2016 Journal of Physical Therapy Science compared sit-ups with leg lifts by using electromyography, which measures the electrical activity of muscle tissue. The sit-up proved to be better in activating the upper and lower rectus abdominis and the external obliques.
The researchers concluded that, when done correctly, sit-ups do a good job of working the abdominal muscles without over-involving the lower limb muscles. The key is doing them by curling the trunk while avoiding active flexing of the hips.
Avoid Getting Injured
For injury-free sit-ups, properly supporting the head and neck is crucial. Sit-ups should always be done with the knees bent. Most people find it necessary to have their feet anchored, either by a workout partner or a stationary object — inserting them under the couch is a common way to go — so the the upper body can rise without toppling backwards.
Anchored sit-ups can increase stress on the lumbar spine, reports Professor Len Kravitz of the University of New Mexico. If you do feel discomfort, don't work through it. Choose an alternative abdominal exercise, such as planks.
- Harvard Health Publishing: "Want a Stronger Core? Skip the Sit-Ups"
- Journal of Physical Therapy Science: "Comparison of Muscular Activities in the Abdomen and Lower Limbs While Performing Sit-Up and Leg-Raise"
- ACE Fitness: "Reality Check: Are Planks Really the Best Core Exercise?"
- ExRx.net: “Fat Loss & Weight Training Myths”