What are the most effective ab exercises in terms of muscle activation?

Question

Aside from the fact that abs are made in the kitchen, there must be differences among different types of ab exercises. Which are the most effective per unit of time in terms of muscle activation?

Tim Ferriss claims in "Four-hour body / 6-minute abs" that the plain-vanilla crunch is "utterly ineffective", and recommends the myotatic crunch instead. However, there's no comparison in the activation of the rectus abdominis when measured with electrodes and an EMG (electromyography machine) between the myotatic crunch and other exercises; also there's no source for the claims:

Bicycle crunch - 248%
Crunch with heel push - 107%
Captain's chair - 212%
Ab roller - 105%
Exercise ball - 139%
Hover - 100%
Vertical leg crunch - 129%
Traditional crunch - 100%
Torso track - 127%
Exercise tubing pull - 92%
Long arm crunch - 119%
Ab rocker - 21%
Reverse crunch - 109%

Some other answers suggest that indeed crunches are vastly sub-optimal.

Answer 1

The Problem with Ab Exercises

Most ab workouts/routines you see are mostly if not entirely composed of bodyweight exercises. These are great for beginners, because there is such a sharp learning curve due to the high body weight and lack of muscle. Unfortunately, they have a significant disadvantage.

The problem is as your muscle grows stronger and adapts to the exercise, your intensity decreases because your bodyweight is effectively static. This means that as you progress your only option will be to do more reps at a low intensity, which is more conducive for building endurance.

Use Weighted Movements

Since optimal muscle growth occurs under high intensity with low reps, the most effective ab exercises are subsequently those that are done with weights since they allow for progressively increased intensity. Since they can be loaded for whatever stage the lifter is in, they are far more consistent in terms of activating muscle in intermediate / advanced lifters.

Loaded ab workouts can be grouped into three separate categories:

• Machines/cables for exercises like pull-down ab crunches.
• Bodyweight exercises where weight can be safely added in, such as hanging leg raises.
• Compound lifts that engage the abs, such as deadlifts, overhead press, squat, etc.

The One Exercise to Rule Them All

Unfortunately I have not seen any study that defines one exercise over others as empirically best (though I am sure there is a ton of "junk science" from all of those "get ripped quick" ab programs). This is not to say the study doesn't exist, simply that I haven't seen it yet.

Personally I have gotten a six pack from both loaded ab exercises, and then again from compound barbell lifts after I took a long break. Both have worked well for me. Presently my focus is on heavy barbell compound lifts, but after the main lifts I do weighted cable crunches (and hyperextensions for balancing antagonists).

Answer 2

Bret Contreras's article, Best Ab Exercises uses EMG to test which exercises best activate the abs. (EMG or electromyography records the electrical activity of muscles.)

Bret charts the mean and peak activation for each muscle, for each exercise. The mean activation is the average level of muscle contraction throughout the exercise motion. Muscles can have different levels of activity at different points of the range so, peak activation or the point of highest level of activation during the repetition is another way to measure the muscle's output.

The entire article is a good read. Bret's conclusions for the top 3 exercises for each abdominal muscles and back extensors are:

• Rectus Abdominis

  Mean: Chin Up, Hanging Leg Raise, Ab Wheel

  Peak: Chin Up, Hanging Leg Raise, Swiss Ball Crunch

• Internal Oblique

  Mean: Ab Wheel from Feet, Ab Wheel from Knees, Bodysaw

  Peak: Ab Wheel from Feet, Bodysaw, Tornado Ball Slam

• External Oblique

  Mean: Ab Wheel from Feet, Hanging Leg Raise, Bodysaw

  Peak: Turkish Get Up, Hanging Leg Raise, Bodysaw

• Erector Spinae

  Mean: Kneeling Cable Lift, Landmine, Reverse Hyper

  Peak: Kneeling Cable Lift, Tornado Ball Slam, Lumbar Extension

So, if his electrode placements are accurate, the above exercises best target the individual abdominal muscles. Interestingly, he also reports different levels of muscle activation for different parts of the rectus.

Answer 3

this exercise here @ https://www.youtube.com/watch?v=GxV54ivkt3A is the best becasue your abs are actually your prime movers as opposed to other exercises where your abs just statically contract and instead of actuallyy causing a movement