How Does Bodybuilding Impact the Kidneys and How Can Kidney Health Be Improved?
Comparing the physiques of bodybuilders in the 1970s to those of the current era, it is clear that immense gains have been made in the sport. However, the gains in muscle mass have not been accompanied by similar progress in the overall health of many competitors. It seems that the overall health of bodybuilders has declined, at least for those at the extreme.
Bostin Loyd, a professional bodybuilder, unfortunately, lost his life in 2022 before reaching the age of 30. Before his death, Bostin Loyd admitted to extensive steroid use and discussed his resulting kidney failure. Ultimately Bostin Loyd succumbed to hyperkalemia, or excessive potassium levels, which is common in people with kidney failure. The tragic loss of Bostin Loyd serves as a reminder of the importance of supporting kidney health while working to achieve a bodybuilder’s physique.
Medical literature is littered with case reports describing “extremely muscled and toned” people in the intensive care unit due to kidney failure1. Many of the reports of kidney failure are due to chronic overuse of anabolic steroids, while others have lesser-known causes including vitamin intoxication and even overconsumption of energy drinks. This article discusses some of the underlying causes of kidney injury in bodybuilders and provides strategies to improve kidney health.
Anabolic-Androgenic Steroids (AAS)
Chronic use of high doses of anabolic-androgenic steroids (AAS) can have detrimental effects on the body’s organ systems. Body pressure often increases with the use of AAS and can lead to long-term damage to the kidneys and the cardiovascular system.
A literature search reveals many reports of such damage(1). A recent study of ten bodybuilders who had used AAS for 10-20 years found kidney damage in all of them. Nine had focal segmental glomerulosclerosis (FSGS), while one had glomerulomegaly. Among eight of the patients who were followed for over two years, all ceased the use of AAs. One patient progressed to kidney failure while the other seven remained on pharmaceutical interventions to preserve their kidney function(2).
Creatine is generally regarded as a safe supplement for most people, however excessive use or use in people with pre-existing kidney disease raises concerns. The kidneys are ultimately responsible for the removal of creatine from the body, and excessive use is theorized to increase the risk of kidney injury(3).
At least two case reports have reported acute kidney injury linked to over-consumption of creatine. One case study details a 32-year-old man who reported weakness and nausea at the hospital. He had taken 20g/day of creatine for 3 days then 1g/day thereafter for 3 weeks. The patient had interstitial nephritis, a form of kidney damage. Upon stopping creatine and being placed on short-term drug therapies, his condition improved profoundly(4).
Overuse of vitamins leading to hospitalization has been reported in numerous bodybuilders, particularly for those using injectable forms. Fat-soluble vitamins, including A, D, and E are of particular concern as they are not easily removed from the body. Vitamin D overload causes the body to absorb an excessive amount of calcium which is harmful to the kidneys(1).
A Brazilian case study series found excessive vitamin use in 16 people who had injected veterinary supplements with vitamins A, D, and E. Acute kidney injury was diagnosed in 13 of the patients and was deemed to be caused by excessively high calcium levels(5).
In contrast to the typical high-protein bodybuilding diet, people with kidney disease are instructed to eat low-protein diets, as the kidneys are responsible for the removal of excess protein and high-protein diets increase the workload of the kidneys. The International Society of Sports Nutrition states that a protein intake of 1.4 – 2.0 g/kg/day is safe. However, it is important to first ensure normal kidney function and to use strategies to ensure kidney health as it has been shown that people who have pre-existing kidney disease have an increased risk of kidney failure when eating a high-protein diet(1).
Energy drinks are often used by bodybuilders as aides to accomplish difficult workouts and are likely innocuous in reasonable quantities. However, excessive consumption of energy drinks has been linked to kidney dysfunction.
One case report described a 40-year-old man who reported to the hospital with an acute kidney injury. He reported drinking 100-120 oz of Red Bull daily for 2-3 weeks. Upon discontinuation of Red Bull, his kidney function improved within two days(6).
In most cases, it is not easy to isolate a single cause of kidney dysfunction because many of the components described above are used together. For example, one case report describes four men with kidney dysfunction who reported using AAS, while consuming 78 – 104 grams of protein powder and taking 15 grams of creatine daily. After stopping the injections and supplements the men regained kidney function to varying levels(7).
How Bodybuilders Can Protect Their Kidneys
The cases described in this article detail bodybuilders who sought to achieve improved physiques but failed to adequately protect their kidneys in the process. Some of these cases involve egregious and excessive use of AAS or supplements. It is important to consider the health of your organs while designing a bodybuilding regimen. It is critical to be cognizant of the effects of ingesting too much of any supplement. Of course, avoidance of AAS is optimal for kidney health but may not be feasible for all bodybuilders depending on their goals. One should aim to identify optimal doses of AAS and supplements that will help achieve goals while minimizing harm.
In addition, be sure to visit a physician regularly. This advice is beneficial to all but particularly to bodybuilders who may be at increased risk for kidney dysfunction. Many AAS can cause increased blood pressure, and high blood pressure is a major cause of eventual kidney failure. Therefore, it is wise to monitor blood pressure while on AAS and use lifestyle interventions or medications to lower blood pressure if needed.
Diet also has a major impact on our kidney health. If one is pursuing a bodybuilding lifestyle that may increase the risk of kidney injury, it is important to optimize other areas. Understand what constitutes a kidney-healthy diet and ensure adequate hydration, as dehydration is damaging to the kidneys. In addition, consider the smart use of supplements that may help to support the kidneys, including Kidney “Stuff.”
The risk of kidney injury to bodybuilders is legitimate as demonstrated by both the medical literature and real-world examples. Long-term health necessitates the recognition of the potential risks and thoughtful actions to mitigate these risks.
1. Gawad, M. & Kalawy, H. Gym nephropathy ‘bodybuilding versus kidney damaging’. Journal of The Egyptian Society of Nephrology and Transplantation 19, (2019).
2. Herlitz, L. C. et al. Development of focal segmental glomerulosclerosis after anabolic steroid abuse. Journal of the American Society of Nephrology 21, (2010).
3. Kim, H. J., Kim, C. K., Carpentier, A. & Poortmans, J. R. Studies on the safety of creatine supplementation. Amino acids vol. 40 Preprint at https://doi.org/10.1007/s00726-011-0878-2 (2011).
4. Ardalan, M., Samadifar, Z. & Vahedi, A. Creatine monohydrate supplement induced interstitial nephritis. Journal of Nephropathology vol. 1 Preprint at https://doi.org/10.5812/nephropathol.7530 (2012).
5. de Francesco Daher, E. et al. Acute kidney injury due to excessive and prolonged intramuscular injection of veterinary supplements containing vitamins A, D and E: A series of 16 cases. Nefrología (English Edition) 37, (2017).
6. Greene, E., Oman, K. & Lefler, M. Energy Drink-Induced Acute Kidney Injury. Annals of Pharmacotherapy 48, (2014).
7. Almukhtar, S. E., Abbas, A. A., Muhealdeen, D. N. & Hughson, M. D. Acute kidney injury associated with androgenic steroids and nutritional supplements in bodybuilders. Clin Kidney J 8, (2015).