Smart Ab Exercises you should do (Leg Raises is a 2!)

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Last updated on February 8, 2023

Everybody wants great abdominal muscles and ultimately a six pack. Yet relatively few people ever end up with such great visible abs. The reason? Training the rectus abdominis, or the abs, is the most misunderstood topic in physique development. One result of the misinformation that has come to be regarded as fact regarding training the abs is that most people are training them the wrong way. In this article, I take a look at some popular ab exercises, rating them according to their effectiveness. I’ll then show you the single best abdominal exercise that you should be doing in order to develop your abs.

The Straight Facts on Ab Training

The first and most fundamental thing to understand about ab training is that you cannot spot reduce body fat. In other words, you could be doing a thousand reps of the best ab exercise every day; but if you don’t remove the fat that covers them through caloric restriction you will never see them.


The next thing to understand when it comes to ab exercises is that the rectus abdominis is one muscle – not two. In other words there is no such thing as the upper ab and the lower ab. So you cannot do exercises to target the lower or upper abdominals. The entire rectus abdominis originates on the pubic bone and inserts onto the front of the ribs. It’s only action is to produce spinal flexion, drawing your chest toward your hips and extending it back.


You should also know that you cannot change the shape of your abdominals. You may have, four, six or eights, separate abdominal sections. But whatever you’ve got, you’ve got them for life!


Ok, let’s start rating some ab exercises . . .


Hanging Leg Raises – Rating: 2

The hanging leg raise involves hanging from a bar and lifting your legs up with the idea of working your abs. However, the legs do not even attach to the abs! This exercise will work your hip flexors, which raise the legs – the abs do not and so are not involved. All that the abs do during this hanging movement is to provide a small degree of isometric stabilization.


Adding weight to the hanging leg raise by holding a dumbbell between your feet will not make this exercise any better for your abs. What it will do is to make it worse for your lumbar spine with increased pull. The lumbar spine is the antagonist muscle to the rectus abdominis. According to the principle of reciprocal innervation, when a muscle is worked its antagonist relaxes. In other words, the movement of bringing up the legs, with or without weight, effectively shuts down any slight ab activation that may have been possible with this exercise.

In addition, hanging from the bar can be detrimental for the shoulder joint. Summing all of this up, the hanging leg raise offers absolutely no benefit for the abs whatsoever – don’t waste your time!

Plank – Rating: 2

The plank is touted as a great ab exercise. It is also known for its core engagement and therefore considered a great core exercise, that will help develop a strong core. Yet, it is a completely isometric exercise. It does not involve any extension or contraction of the target muscle. Isometric exercises were debunked as an effective muscle builder decades ago. We don’t do isometric exercises to build our chest, or quads or biceps – so why should we do one for our abs?


Logic tells us that we shouldn’t!


An isometric contraction exercise is never going to be as good as a dynamic movement exercise. So, even the least effective ab exercise that involves spinal flexion is more productive for your abs than the plank position.

Knee Tucks – Rating: 3

Knee tucks has a start position sitting on the edge of a bench with your legs out on an angle and pulling your knees in toward your torso, causing hip flexion. There is virtually no dynamic movement in the rectus abdominis when you do this exercise. It simply contracts isometrically. In this sense, it is similar to the plank. Isometric contraction, as we have already noted, will neither strengthen nor develop your abdominals. Your abs are not involved in movement of the hips so this is not an effective abdominal movement.


Seated Cable Ab Crunch – Rating: 10

The seated cable ab crunch has you seated on a back supported bench set a few feet in front of a pulley machine. The pulley should be set level with your shoulders and have a rope handle attached. Grab the handles above your head and crunch down with the pivot point being your mid spine. Your torso below that point should remain against the back of the bench. On the return strtech back to fully extend the abs. Choose a weight that will allow between 15 to 30 reps.


Doing the ab crunch in this manner allows for full range of motion of the abs. Their job is to contract and extend the spine. When you are lying flat on the floor you can do a good job of contracting but your ability to extend the abs is compromised by the floor. Using a cable machine for your ab crunches also makes it much easier to increase the resistance. Remember, your abs are a muscle and just like all of your other muscles, they respond to progressive resistance.

How to do the Seated Cable Ab Crunch

Wrap Up

When you are exercising your abs, have clearly in mind what the function of that muscle group is – to contract and extend the spine. Know, too, that the rectus abdominis does not attack itself to your legs. Those two pieces of information will automatically rule out many of the most popular ‘ab’ exercises that you see be doing ad nauseum in every gym on the planet.


If you are serious about working your abs, you will perform the most effective ab exercise for them. That exercise is the seated cable ab crunch. It is more biomechanically efficient than bicycle crunches, the reverse crunch, captain’s chair or any other crunch variation. I suggest that you work your abs once per week with this exercise, performing six sets. Here is a rep scheme that has proven very effective for many people:


  • Set One: 30 reps
  • Set Two: 25 reps
  • Set Three: 25 reps
  • Set Four: 20 reps
  • Set Five: 20 reps
  • Set Six: 15 reps


SmartFitnessResults has great articles on fitness and nutrition from experts for the lower and upper body. This includes how to articles (for example how to do a barbell back squat, the mountain climber exercise); and best exercise advice (for example best battle rope exercise, best stability ball exercises, best medicine ball exercises, best arms and legs exercises).


Whatever your fitness goals ( for example reduce body fat percentage) we should have articles to help you. Enjoy !

Steve Theunissen has qualified from the International Sports Sciences Association (ISSA) and is a certified Personal Trainer and Nutritionist. He has over 30 years experience in fitness and nutrition and currently working with famous fitness professionals. He is currently living in New Zealand with is wife and daughter.

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