In the competitive arena of bodybuilding, a narrow waist and wide shoulders represented the pinnacle of perfection. In recent years, a strange and controversial trend has emerged among bodybuilding fans a muscular body with an unusually large, bulging abdomen. Bodybuilders developing unusually large stomachs is often linked to a condition commonly referred to as bubble gut or palumboism.

But what causes certain bodybuilders to develop these unusually large stomachs despite having low body fat? This occurs due to a mix of performance-boosting substances, extreme nutritional plans, and the growth of internal organs.

What Is a “Bubble Gut” in Bodybuilding?

In the fitness world, the term bubble gut describes a specific type of abdominal distention where the midsection protrudes unnaturally, despite the athlete having extremely low body fat and visible muscle definition. Unlike typical belly fat, which can be burned off through diet and exercise, a bubble gut remains prominent even when a bodybuilder is in peak “shredded” condition.

Although bubble gut is not an official medical condition listed in clinical manuals, it has emerged as a significant topic of discussion and research in the bodybuilding community and among sports medicine professionals. Both experts and enthusiasts utilize the term to examine how contemporary training, rigorous nutrition, and particular performance-enhancing drugs lead to this “mass monster” look.

1. Excessive Growth Hormone (GH) Use

One of the leading contributors to bubble gut is long-term, high-dose growth hormone (HGH)^[1] use.

How HGH Affects the Abdomen:

Leads to enlargement of organs (visceromegaly^[2]), particularly
Thickens the abdominal wall
Raises internal pressure pushing the stomach outwards

In contrast to muscle hypertrophy^[3], the internal organs increase in all dimensions, leading to an increase in the abdominal girth and giving a rounded abdomen.

2. Insulin Abuse and Gut Distension

In many cases bodybuilders use HGH along with insulin to help their bodies absorb more nutrients and build muscles.

Effects of Insulin on the Gut:

encourages the buildup of fat around internal organs
Causes frequent bloating due to increased carbohydrate intake
Over time, it causes persistent abdominal distension.

The abdomen may appear permanently enlarged due to frequent insulin surges.

3. Extreme Caloric Intake & Food Volume

Professional bodybuilders often consume 6,000–10,000+ calories per day, which puts constant stress on the digestive system.

Increased stomach volume
Persistent stomach fullness
Elevated gas and abdominal distension
Expansion of abdominal tissues

Over time, the stomach adapts to large food volumes, contributing to the bubble gut appearance.

4. Visceral Fat Accumulation (Not Subcutaneous Fat)

Even when body fat is low, bodybuilders can have visceral fat^[4], which is fat that is stored deep around the organs.

Why it happens:

The use of steroids alters the distribution of fat in the body
Insulin resistance
Hormonal Imbalances Visceral fat causes the abdominal wall to bulge, which makes the stomach appear larger even if the abs are visible.

5. Weak or Relaxed Transverse Abdominal Muscles

The transverse abdominis functions as a natural corset, keeping the abdominal contents in place

Elements of Contribution:

Excessive focus on intense weightlifting
Disregard for fundamental stability exercises
Persistent abdominal tension while lifting heavy objects
When this muscle loses strength, the abdomen sticks out even further.

6. Chronic Bloating and Gut Health Issues

Long-term supplement use, high protein diets, and frequent meals can disrupt gut health.

Prevalent Digestive Problems in Bodybuilders:

Impaired digestive movement
Gas buildup
Modified gut microbiome^[5]
Inflammation of the gastrointestinal tract
This leads to ongoing bloating that exacerbates the bubble gut phenomenon

While growth hormone misuse, insulin resistance, and visceral organ enlargement play a role, these factors are explained in detail in The Bubble Gut Blueprint: causes and solutions for abdominal distension.^[6]

Final Thoughts

The large, protruding stomachs that are occasionally seen in certain bodybuilders are not the result of laziness or poor conditioning. These bubble guts are the result of many years of hard training, the use of performance-enhancing drugs, and the intentional overconsumption of calories and nutrients. The bubble gut phenomenon highlights the unseen cost of pushing the human body past its limits.

FAQs

Q1. What causes bubble gut in bodybuilders?

Ans. Bubble gut in bodybuilders can be because of certain reasons like high-carb diets, excessive protein intake, growth hormone use and constipation.

Q2. What is growth hormone?

Ans. Growth hormone is a peptide hormone which is produced by pituitary gland that helps in growth, cell reproduction and regeneration.

Q3. Is bubble gut a sign of poor health?

Ans. It is not, but sometime it can be because of poor digestion.

Q4. Can I boost Growth Hormone naturally?

Ans. Yes, you can boost it naturally by doing exercise daily, taking good sleep, and having protein-rich diets.

References

We value truthful content. 6 sources were referenced during research to write this content.

Ranabir, S., & Reetu, K. (2011). Stress and hormones. Indian Journal of Endocrinology and Metabolism. Medknow. http://doi.org/10.4103/2230-8210.77573
Lindholt, J. S., Juul, S., Fasting, H., & Henneberg, E. W. (2005, March 9). Screening for abdominal aortic aneurysms: single centre randomised controlled trial. Bmj. BMJ. http://doi.org/10.1136/bmj.38369.620162.82
Seynnes, O. R., de Boer, M., & Narici, M. V. (2007, January). Early skeletal muscle hypertrophy and architectural changes in response to high-intensity resistance training. Journal of Applied Physiology. American Physiological Society. http://doi.org/10.1152/japplphysiol.00789.2006
Birbrair, A., Zhang, T., Wang, Z.-M., Messi, M. L., Enikolopov, G. N., Mintz, A., & Delbono, O. (2013, August 15). Role of Pericytes in Skeletal Muscle Regeneration and Fat Accumulation. Stem Cells and Development. SAGE Publications. http://doi.org/10.1089/scd.2012.0647
Moszak, M., Szulińska, M., & Bogdański, P. (2020, April 15). You Are What You Eat—The Relationship between Diet, Microbiota, and Metabolic Disorders—A Review. Nutrients. MDPI AG. http://doi.org/10.3390/nu12041096
Jesus, L. E. de ., Cestari, A. B. C. S. S., Filho, O. C. da S., Fernandes, M. A., & Firme, L. H. (2015, September). Aerofagia patológica: uma causa rara de distensão abdominal crônica. Revista Paulista de Pediatria. FapUNIFESP (SciELO). http://doi.org/10.1016/j.rpped.2015.01.003