Bodybuilding is a demanding sport, requiring not just physical strength but also optimal nutrition to support muscle growth, recovery, and overall performance. If you have one kidney or are worried about kidney health, picking the right workout supplements takes some serious thought and planning. Here, I'll offer some research-backed insights to help you safely incorporating supplements into your regimen while prioritizing kidney health.
Workout supplements and their impact on kidney health
Ready to explore workout supplements and what they mean for your kidneys? I'll cover the ones bodybuilders often use and how they can affect your kidney health. This should help you make smarter choices for your fitness journey while keeping your kidney healthy.
Whey protein
Widely favored among bodybuilders for muscle recovery and growth, whey protein should be consumed in moderation. Excessive intake can strain the kidney due to increased nitrogenous waste; the kidney must filter out this waste, potentially putting stress on its function. Interestingly, one animal study found that while consuming a high-protein diet impacted renal health in sedentary rats, resistance training seemed to have a protective effect on the kidneys.
Recommendation: When selecting protein supplements, opt for high-quality whey protein isolate. Consume in moderation, aiming for 0.8-1.0 grams of protein per kilogram of bodyweight per day. (Some studies recommend exercising caution when you have compromised renal function.) Monitor protein intake closely and adjust as necessary to maintain kidney health.
Plant-based protein
Compared to animal-based proteins, plant-based options are gentler on the kidneys. They have lower nitrogen levels and are easier for the kidney to process. And recent studies suggest that plant proteins, like the ones found in tofu and edamame, can be just as good for building muscle as whey and other animal proteins. Plant-based proteins also offer other health benefits that reduce the risk of other chronic diseases like heart disease and diabetes.
Recommendation: Opt for high-quality plant-based proteins like pea, rice, or hemp. Aim for up to 1.0 grams of protein per kilogram of bodyweight and monitor intake to maintain kidney health.
Creatine monohydrate
Creatine is a popular supplement for increasing muscle mass and strength during exercise. But its impact on kidney health remains a (hot) topic of debate. Some studies suggest that while creatine may elevate creatinine levels—the current marker for kidney function—it may not directly damage the kidneys. Nonetheless, people with one kidney should use caution.
Recommendation: Consult a healthcare provider before starting creatine supplementation and consider kidney function tests. Follow the recommended daily dosage of 3-5 grams and stay well-hydrated to minimize side effects.
Branched-chain amino acids (BCAAs)
BCAAs—leucine, isoleucine, and valine—support muscle protein synthesis, making them popular among athletes and fitness enthusiasts for promoting muscle growth and recovery. Some studies suggest that BCAAs can help reduce muscle soreness and fatigue, particularly when taken before or during exercise. Yet, high doses of BCAAs can increase the nitrogen load on the kidney; one animal study found that prolonged intake, especially through supplements, may result in higher levels of nitrogenous waste products in the body.
Recommendation: If your kidneys are compromised, go easy on BCAAs. Stick to 5-10 grams a day from whole foods like meat, dairy, eggs, and legumes. And always check with a doctor before taking high doses of BCAAs if you have kidney issues.
Essential amino acids (EAAs)
EAAs are essential for building and repairing muscles, but your body can't produce them, so you need to get them from food or supplements. There are nine EAAs—histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine—and each has a specific role in supporting cellular function and tissue maintenance. Studies show that consuming EAAs, whether through meals or supplements, can improve muscle protein synthesis and support recovery following exercise. But there's not much research on how they affect kidney function overall.
Recommendation: Be careful with EAA supplements, sticking to under 15 grams a day. Get regular kidney function tests to keep an eye out for any possible issues.
Citrulline
Citrulline, a natural component of watermelon and synthesized by the body, is often taken as L-citrulline in supplements. Research suggests that L-citrulline can indeed boost nitric oxide levels, promoting improved blood flow. And this improved circulation may increase exercise performance and could potentially benefit conditions like high blood pressure.
Citrulline is considered safe for kidney health when taken in moderate amounts, but too much can stress your kidneys.
Recommendation: Take around 6 grams daily but consult a doctor before starting. They can make sure the supplement won't cause issues for your kidney
Beta-alanine
Beta-alanine is known to help buffer acid in muscles, and this, in turn, can improve exercise performance and muscle endurance, according to research. While considered safe, there is limited data on its impact on those with one kidney. However, one study found that taking 6.4 grams of beta-alanine daily for 24 weeks didn't affect blood markers for kidney, liver, or muscle function. Another found that consuming beta-alanine at typical doses doesn't have harmful effects on users.
Recommendation: Stick to 4 grams a day at most. Before you start, talk to a healthcare professional to guarantee the supplement won't harm your kidneys.
Taurine
Taurine, a free amino acid in the plasma and cytosol, has been shown to have a protective effect on the kidneys, which play a key role in maintaining taurine balance. Studies suggest that taurine can reduce oxidative stress and inflammation, potentially benefiting overall kidney function. Still, the long-term effects on people with one kidney are not well-documented.
Recommendation: Limit yourself to 3 grams daily of taurine but consult a healthcare provider beforehand. They can provide personalized guidance to make sure the supplement won't affect your kidneys.
Glutamine
Glutamine helps the kidneys balance acidity and remove extra nitrogen from the body. It's also important for making the amino acid arginine, which helps the body build protein. But taking too much glutamine might cause problems for your kidneys, according to research. In one study, researchers gave extra glutamine to rats with and without diabetes for 15 days. They found that the rats given extra glutamine had more inflammation in their kidney tissue and changes in their kidney structure. This suggests that taking too much glutamine, especially if you have high blood sugar, could make kidney damage worse.
Recommendation: Try for around 4 grams daily but speak with a doctor before starting glutamine. They'll give you personalized advice to avoid kidney issues.
Other supplements for consideration
Tongkat Ali and Ashwagandha: Tongkat Ali and Ashwagandha are herbs used in traditional medicine for various purposes. While some believe they can help with things like energy, stress, and sexual health, there's not a lot of scientific evidence to support these claims. If you have kidney problems or are on medication, consult a doctor before using these herbs.
Caffeine: Caffeine is a common pre-workout supplement known for boosting energy and focus. Research suggests that moderate consumption is generally safe for people with one kidney, but excessive intake may pose risks to blood pressure and kidney function. Consult with a healthcare provider before starting caffeine supplementation.
Fish oil/omega-3 fatty acids: Fish oil supplements containing omega-3 fatty acids help reduce inflammation and support heart health, helping recovery. Studies show potential benefits for people with one kidney, but it's important to avoid high doses that could strain the kidneys. Regular kidney function monitoring is essential.
HMB (beta-hydroxy beta-methyl butyrate): HMB supplements may help reduce muscle breakdown and promote growth, especially during intense training. Research suggests cautious use for people with one kidney, with regular kidney function checks. Before taking HMB supplements, consult your doctor.
ZMA (zinc, magnesium, vitamin B6): ZMA supplements may boost immune function and recovery, as well as benefit people with one kidney. One study found that zinc may protect against worsening kidney dysfunction, while another discovered that magnesium may help prevent kidney damage from too much phosphate buildup. For its part, vitamin B6 helps kidneys process proteins and regulate oxalate levels, and one study suggests it might lower the risk of kidney stone formation in women.
5 actions to protect your one kidney while taking supplements
Educate yourself: Understand the specific interactions between your chosen workout supplements and kidney function. Knowledge is power, and the more you know, the better equipped you'll be to make informed decisions.
Hydrate strategically: Experiment with different hydration strategies tailored to your body's needs. This might include electrolyte-enhanced water, herbal teas, or homemade hydration blends to optimize kidney health during intense workouts.
Seek expert advice: Surround yourself with a supportive network of healthcare professionals, including not only doctors but also nutritionists, dietitians, and trainers like me who specialize in kidney health. Their collective expertise can provide invaluable guidance for your unique fitness journey.
Supplement mindfully: Explore alternative or lesser-known workout supplements that have minimal impact on kidney function while still supporting your fitness goals. For example, consider natural options like beetroot powder for improved endurance or collagen peptides for joint health, which are gentler on the kidneys compared to traditional supplements.
Track and tweak: Keep a detailed journal of your supplement intake, hydration levels, and kidney function test results. By closely monitoring these metrics over time, you'll gain valuable insights into what works best for your body and can make personalized adjustments accordingly.