Having defined abdominal muscles, often referred to as a ‘six-pack’, is considered by many to be the holy grail of fitness goals. But some people seem to be genetically predisposed to develop only 4 distinct abdominal muscles, known as ‘4 pack abs’. So how rare is it to have just 4 abdominal muscles showing instead of 6?
What are the abdominal muscles?
The abdominal muscles are a group of muscles that extend from the rib cage to the pubic bone and from the spine outward to the sides. The main abdominal muscles are:
- Rectus abdominis – this long flat muscle extends along the length of the abdomen and is split into left and right halves by the linea alba, giving the six pack appearance.
- External obliques – these muscles run diagonally down and inward from the lower ribs to the pelvis on each side.
- Internal obliques – sit just under the external obliques, running perpendicular to them.
- Transversus abdominis – the deepest layer of abdominal muscles that wrap around the torso.
The rectus abdominis is the muscle that becomes visible as a six-pack when developed through strength training. But some people naturally develop just 4 distinct segments of the rectus abdominis instead of 6, leading to ‘4 pack abs’.
What causes 4 pack abs?
There are a few possible reasons why some people develop 4 pack instead of 6 pack abs:
- Genetics – Some people are simply born with fewer segments of the rectus abdominis muscle. Each segment is separated by fibrous bands of connective tissue called tendinous intersections. Most people have 3 of these fibrous bands that divide the muscle into 6 segments, but in those with 4 pack abs there are only 2 tendinous intersections instead of 3.
- Incomplete muscle development – Even genetically predisposed to 6 packs, some people do not achieve full muscular development, so not all 6 segments become visible. Poor nutrition or insufficient training stimulus can mean only the upper 4 segments develop well enough to show.
- High tendinous intersections – Sometimes the tendinous intersections do not run symmetrically across the entire width of the rectus abdominis. If the lower intersections are set higher, only 4 segments will be visible on the surface.
So in summary, having fewer segments of the rectus abdominis muscle due to genetic factors is the predominant reason some people present with 4 packs instead of 6 packs.
How common are 4 pack abs?
There are no large scale studies quantifying the prevalence of 4 pack abs compared to 6 packs. However, experts estimate that around 10-15% of people with well-developed abs will have just 4 abdominal segments visible rather than the typical 6 packs.
Based on this estimate, 4 pack abs are relatively uncommon compared to 6 packs, but certainly not extraordinarily rare. Their occurrence is high enough that many personal trainers and fitness experts will have come across clients who display the 4 pack formation.
Are 4 packs and 6 packs equally impressive?
In terms of impressiveness, 4 pack and 6 pack abs are comparable physical achievements. Both require adhering to a strict training and nutrition regimen to reduce body fat levels and develop the abdominal musculature.
The main difference is that someone with a natural predisposition to 4 packs may find it marginally easier to achieve visible 4 pack definition compared to someone pursuing the standard 6 pack look. However, both require consistent hard work and dedication to diet and exercise.
The 4 pack appearance is no less impressive or aesthetic than a 6 pack on a fit physique. Many models and athletes with top-tier physiques in fact exhibit the 4 pack formation rather than 6 packs.
Can you convert 4 packs to 6 packs?
It is not really possible to change the structure of your abdominal muscles from displaying as 4 packs to 6 packs. As the main factor is genetic limits on the number of muscle segments, you cannot add extra divisions by training the abs.
However, someone with high tendinous intersections or incomplete muscular development may find they can achieve 6 pack definition with extremely low body fat levels. The lower segments may start to become visible at body fat percentages under 6-8% for men and 16-18% for women.
But for most, the number of packs will be set based on your inherited abdominal muscle structure. With dedicated training, 4 packs can be achieved just as impressively as 6 packs.
Training and nutrition tips
Here are some evidence-based tips for maximizing abdominal definition whether you have the potential for 4 or 6 packs:
- Perform compound lifts like squats, deadlifts, pull-ups, and rows to build overall muscle mass. Larger abdominal muscles show through better.
- Include targeted ab training with planks, leg raises, crunches, sit-ups, and ab wheel rollouts. Shoot for 3-4 ab workouts per week.
- Incorporate high protein foods like meats, eggs, dairy, beans, and soy products to support muscle growth.
- Reduce overall body fat percentage through a moderate calorie deficit. Losing fat reveals the abdominal muscles.
- Include healthy fats from sources like nuts, seeds, olive oil, avocado and fatty fish. These support hormone production.
- Engage in regular cardio like running, cycling, swimming for a calorie deficit. Monitor changes with photos.
By combining strength training, nutrition, cardio, and patience, you can achieve impressive visible 4 pack or 6 pack abs. Just stay consistent!
Example physiques
Here are some examples of impressive 4 pack and 6 pack physiques:
4 Pack | 6 Pack |
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Conclusion
In summary, while 6 packs are the more common presentation, having 4 pack abs is not at all uncommon or problematic. It simply comes down to natural limits on the segments of the rectus abdominis muscle in some individuals.
Both 4 packs and 6 packs require rigorous training and dieting to achieve, so are equally impressive as indicators of fitness. It is difficult to convert 4 packs to 6 packs as segmentation is mostly genetically determined.
With smart programming focused on compound lifts, targeted ab exercises, cardio and quality nutrition, you can reveal an aesthetically impressive set of abs whether you have the potential for 4 or 6 packs.