What Is the Rarest “Abs”? It Depends: A 10-Pack for Muscles, AB-Negative for Blood

The rarest “abs” depends on what you mean: for abdominal muscles, a true 10‑pack is the rarest visible configuration; for blood types, AB‑negative is the rarest ABO/Rh group worldwide. Below, we explain both interpretations, how each arises, and why the distinction matters.

Contents

If You Mean Abdominal Muscles
If You Mean the AB Blood Group
Summary

If You Mean Abdominal Muscles

When people talk about “abs,” they usually mean the rectus abdominis, the paired muscles on the front of the torso separated by the linea alba. The number of “packs” (4, 6, 8, or rarely 10) reflects how many tendinous intersections segment these muscles. This is a genetic and anatomical variation—not something you can change with training—and the rarest configuration reported is a true 10‑pack.

How Many “Packs” Exist and How Common Are They?

The appearance of your abs is determined by the number and placement of tendinous intersections, plus body-fat levels that reveal or obscure them. While exact global percentages aren’t established in medical literature, the relative frequency is well understood.

4‑pack: Results from fewer tendinous intersections; seen in a minority of people.

6‑pack: The most typical configuration when lean enough for muscle segmentation to be visible.

8‑pack: Less common; arises when there’s an additional pair of intersections.

10‑pack: Extremely rare anatomical variant documented in isolated cases; far less common than an 8‑pack.

In practice, most lean individuals who “show abs” display up to six segments; eight is notably less common, and ten is an outlier rooted in unusual muscle segmentation.

Why Training Can’t Create a 10‑Pack

Exercise can hypertrophy (grow) and define your abs, but it cannot increase the number of tendinous intersections. Genetics sets the blueprint. To make whatever pack you have visible, you need a combination of muscle development and low enough body-fat levels, alongside good posture and core stability.

Performance and Health Matter More Than Count

A strong core supports spinal stability, athletic power transfer, and injury prevention. Exercises that challenge anti-rotation, anti-extension, and hip-to-rib control (planks, dead bugs, carries, hanging leg raises) build functional strength whether you have a 4‑, 6‑, 8‑, or rare 10‑pack.

If You Mean the AB Blood Group

In the ABO/Rh blood system, AB‑negative (AB−) is the rarest type globally. Its rarity follows from two factors: AB is the least common ABO phenotype in many populations, and Rh‑negative is uncommon worldwide—especially in East and South Asian populations—making their combination especially scarce.

How Blood Type Rarity Generally Ranks

While distributions vary by region and ethnicity, the following ordering is a common global pattern from most to least common, with AB− at the bottom. Prevalence figures vary, but AB− typically accounts for roughly half a percent of donors in the United States and even less in many parts of Asia.

O positive (O+)

A positive (A+)

B positive (B+)

O negative (O−)

A negative (A−)

AB positive (AB+)

B negative (B−)

AB negative (AB−) — rarest

Local patterns can shift (for example, B+ is more common in parts of South Asia), but AB− remains scarce across populations due to the low prevalence of Rh negativity combined with AB.

Why AB− Matters in Transfusion Medicine

AB− red blood cells can be given only to AB− recipients, which makes the type vital but logistically challenging because the pool of both donors and patients is small. AB plasma (regardless of Rh) lacks anti‑A and anti‑B antibodies, making it a “universal” plasma donation—hospitals prize AB plasma for emergencies when there’s no time to match. For red cells, O− is the universal donor, while AB+ is the universal recipient; AB− recipients typically require Rh‑negative, ABO‑compatible units (O−, B−, A−, or AB−).

Summary

If you’re asking about muscles, the rarest abs are a true 10‑pack—a genetic anatomical variant of the rectus abdominis. If you’re asking about blood, the rarest “ABs” are AB‑negative—the scarcest ABO/Rh combination worldwide and a critical consideration for transfusion planning and blood donation.

Which are the hardest abs to get?

The 10-pack is generally the hardest to achieve, but the lower abs are the most difficult to develop visually due to their location and the body’s predisposition to store fat there. This combination of genetic predisposition to a lesser-defined pack and the challenge of reducing lower abdominal fat requires significant, dedicated effort through both proper diet and targeted exercise.
Genetics and Rarity

10-Pack: The most genetically rare, only a small percentage of people can develop 10-pack abs, which depend on individual muscle structure and body composition.

Visibility and Fat Distribution

Lower Abs: Making the lower abdominal muscles show is challenging because the body stores fat in this area. This evolutionary trait means that even with developed muscle, they can remain hidden under a layer of fat, making them hard to show off.

Achieving Lower Ab Visibility

Diet: Opens in new tabA significant factor is diet. “Abs are made in the kitchen” is a common saying, emphasizing that a low body fat percentage is essential for muscles to be visible.
Targeted Training: Opens in new tabExercises that specifically target the lower abs are needed, though it’s difficult to achieve significant isolation of this area.
Overall Core Strength: Opens in new tabWhile exercises like the Dragon Flag or Weighted Plank build incredible core strength, focusing on exercises that can be performed with control and stability, combined with a clean diet, is key to making the lower abs pop.

Which type of abs is rare?

While 6 packs are the most common, some bodybuilders such as Schwarzenegger can only attain a 4 pack. This is due to humans being born with different amounts of fascia bands. The most you can have is a 10 pack, which is rare.

Are 8 pack abs rare?

Yes, 8-pack abs are rare because their presence is determined by genetics, and only about 20% of people are born with the necessary genetic structure to potentially develop one. To achieve a visible 8-pack, a person also needs to have a low body fat percentage, along with the correct genetic predisposition for four rows of tendinous intersections that divide the rectus abdominis muscle.
Why 8-pack abs are rare:

Genetics determine the number of divisions: Opens in new tabWhether you can have an 8-pack is determined by the number of horizontal bands of connective tissue (tendinous intersections) you have in your abdominal area, according to Live Science.
Fewer than 6-pack genetics: Opens in new tabWhile 6-pack genetics are the most common (around 60% of people), only about 20% have the genetic structure for an 8-pack.
Low body fat required: Opens in new tabEven with the right genetics, you still need to have a very low body fat percentage to make the lower abs visible, making an 8-pack a combination of genetic luck and dedication.

How 8-pack abs are formed:

Abdominal muscle divisions: The “packs” are the visible divisions of the rectus abdominis muscle.
Tendinous intersections: These are bands of connective tissue that divide the rectus abdominis into sections.
The 8-pack configuration: An 8-pack forms when a person has four tendinous intersections instead of the three typically found in a 6-pack, creating eight distinct abdominal muscles.

How rare is 10 pack abs?

A 10-pack of abs is extremely rare because the number of distinct abdominal muscle segments, or “packs,” is determined by genetics. While most people are born with the genetics to develop a 6-pack, and some have the genetics for an 8-pack, only a very small number of people are born with the five horizontal tendinous intersections in their rectus abdominis muscle needed for a 10-pack.
Why 10-pack abs are so rare:

Genetics dictate the structure: The layout and number of visible abdominal muscles are predetermined by the number of tendinous bands you are born with.
Most people have a 6-pack structure: Research suggests that approximately 60% of the population is genetically predisposed to a 6-pack.
Fewer people have an 8-pack: Around 20% of people are born with the four tendinous intersections for an 8-pack.
The rarity of a 10-pack: A 10-pack requires a rectus abdominis muscle with five tendinous intersections, a genetic variation that is uncommon.

What it takes to see them:
Even if you have the genetic potential for a 10-pack, it would still require an extremely low body fat percentage and significant muscle development to become visible.