The most common adaption mistake.
Athletes who transition to a ketogenic lifestyle often report a noticeable drop in performance during the initial weeks. Issues such as fatigue, cramping, and decreased strength are common, and much of this can be attributed to changes in sodium balance.
As I review more and more research, I see some basic steps in the adaptation process being completely ignored. Increasing sodium intake is one of the most egregious.
Let’s explore why keto-adapted athletes may require more sodium, the role sodium plays in performance, and how to optimize sodium intake during and after adaptation.
Keto-Adaptation causes increased sodium loss
When carbohydrate intake drops significantly, glycogen levels in the body decrease. Since glycogen binds water, a reduction in glycogen leads to increased water excretion. Along with this, lower blood glucose results in a general reduction of insulin levels. Insulin plays a key role in sodium retention, so as insulin decreases, the body excretes more sodium (Brands & Manhiani, 2012). Without sufficient sodium intake, athletes may experience dizziness, fatigue, and muscle cramps, commonly called the “keto flu.”
During this transition, the body must find a new balance to regulate sodium and water levels effectively. This balance ensures sodium can perform its roles in hydration, nerve signaling, and thermoregulation.
The Role of Sodium in Sports Performance
Sodium is vital for athletic performance for several reasons:
- Sodium helps maintain blood volume, which directly influences oxygen delivery to working muscles. Higher blood volume improves aerobic capacity and endurance. Research by Mora-Rodriguez & Hamouti (2013) emphasizes sodium’s role in sustaining blood volume during exercise.
- Sodium plays a critical role in thermoregulation, helping the body regulate temperature and delay overheating. Studies, such as those by Muller et al. (2011), show that adequate sodium intake can slow the rise in core temperature during prolonged physical activity.
- Sodium has been shown to enhance fat metabolism by potentiating lipolysis, the process of breaking down fat for energy. This is particularly important for keto-adapted athletes, who rely on fat as their primary energy source. Wu (2023) found that higher sodium intake can increase the availability of fatty acids in the bloodstream.
As you can see, there are some very important aspects of performance, including keto-adaptation itself, that require sodium. Imagine the difficulty your body has changing from carbohydrates to fat as a primary fuel substrate but not being able to break down body fat for fuel efficiently.
One study I’ve found so far that did include sodium supplementation had this to say about the results:
“With these supplements maintaining daily intakes for sodium at 3–5 g/d and total potassium at 2–3 g/d, our adult subjects were able to effectively maintain their circulatory reserve (ie, allowing vasodilatation during submaximal exercise) and effective nitrogen balance with functional tissue preservation.” (Phinney, 2004)
I’m not saying that increasing sodium will make the adaptation period a seamless experience. But, I have seen it dramatically reduce the initial symptoms and resolve to improve performance faster than without.
For most people, adaptation can take up to 12 weeks or more. I usually put the 12-week mark at the long end if the individual isn’t being consistent with their carb and electrolyte intake, recovery, and sleep. Like I said the adaptation process has a lot of moving parts. Sodium is just one thing to consider.
During the transition to having a fat and ketone dominate metabolism, the imbalance in sodium and hydration will cause periods of hyper and hyponatremia, or high and low sodium levels in the body. By keeping the sodium intake high in an environment where the body will readily remove excess, a buffer is created that allows for adequate availability of sodium at all times throughout this volatile period.
Once athletes have adapted, they may not need as much, and they are free to experiment with reducing daily intake and/or using sodium as a pre-workout or ergogenic aid.
Sodium as an Ergogenic Aid
Sodium supplementation can serve as a powerful ergogenic aid, enhancing performance during training and competition.
Pre-loading sodium before a workout increases blood volume and delays fatigue. Mora-Rodriguez & Hamouti (2013) suggest that sodium pre-loading can significantly improve endurance performance.
During prolonged exercise, sodium supplementation can prevent hyponatremia and maintain electrolyte balance. Veniamakis et al. (2022) highlight that sodium intake during activity helps sustain performance and prevents serious health issues.
So ketogenic athletes need more sodium and can even use sodium to help performance. How does that work?
Sodium Needs During and After Keto Adaptation
In the early stages of keto-adaptation, the body excretes sodium at a higher rate than it is used to. Increasing sodium intake to 3–5 grams per day during this period can help mitigate common adaptation symptoms and maintain performance. Providing more sodium than usual allows the body to establish a new homeostasis without compromising training quality.
Once fully adapted, the body becomes more efficient at managing sodium and hydration homeostasis. At this point, athletes may reduce daily sodium intake to 2–3 grams while using targeted supplementation during intense training sessions or competitions.
Practical Sodium Strategies for Keto-Athletes
Let me preface this by saying that I have seen some people who have been keto-adapted for years and regularly get upwards of 10 grams of sodium per day and others who don’t add any salt to anything they eat. These ranges are based on a combination of my clinical experience and the general recommendations for sodium intake.
- Daily Intake During Adaptation: 3–5 grams of sodium per day.
- Daily Intake Post-Adaptation: 2–3 grams per day.
- Pre-Loading Sodium: Consume 1–2 grams of sodium 1–2 hours before endurance events or intense workouts.
- Intra-Workout Supplementation: Take 500–1000 mg of sodium per hour during long-duration or high-intensity activities, especially in hot conditions.
For reference, I’m 52, I weigh 190 pounds at about 15% body fat. I do CrossFit 3–4 days a week. I’ve been following a carnivore diet for 7 years. I went for years doing between 6 and 8 grams of sodium daily. Only recently have I cut back to 3 to 5 grams, and I have not noticed any difference in performance. I’m looking to cut back because 1. I noticed I pee a lot, which is a sign of overconsuming sodium, and two electrolytes are expensive!!
Summary: You should try it if you haven’t already!
Transitioning to a ketogenic lifestyle can present significant challenges for athletes, especially in the early weeks when they often experience fatigue, muscle cramps, and reduced performance. A key factor in these struggles is sodium depletion. As glycogen stores decrease and insulin levels drop, the body loses more water and sodium, disrupting the balance necessary for optimal hydration, muscle function, and thermoregulation.
Sodium plays a crucial role in athletic performance by maintaining blood volume, supporting fat metabolism, and regulating body temperature. During keto adaptation, sodium needs increase significantly, with recommended intake ranging from 3–5 grams per day to buffer against symptoms of “keto flu” and support the body’s shift to fat as its primary fuel source. Once adaptation is complete, athletes can experiment with reducing daily intake to 2–3 grams and using sodium as a pre-workout or intra-workout supplement to enhance performance.
If you’ve been hesitant to try a ketogenic lifestyle because you’re afraid it will hurt your performance, don’t let that stop you. The key is ensuring you get enough sodium during the adaptation period. Challenge yourself to commit to the process, stay consistent with your sodium intake, and see how your body adapts. You might just discover that by dialing in your electrolytes, you can thrive on a ketogenic diet without compromising your athletic goals!
References
Brands MW, Manhiani MM. Sodium-retaining effect of insulin in diabetes. Am J Physiol Regul Integr Comp Physiol. 2012 Dec;303(11):R1101–9. doi: 10.1152/ajpregu.00390.2012. Epub 2012 Oct 3. PMID: 23034715; PMCID: PMC3533616.https://pmc.ncbi.nlm.nih.gov/articles/PMC3533616
Mora-Rodriguez, Ricardo & Hamouti, Nassim. (2013). Salt and Fluid Loading: Effects on Blood Volume and Exercise Performance. Medicine and sport science. 59. 113–9. 10.1159/000341945. PDF link
Muller, M., Ryan, E., Bellar, D. et al. Effect of acute salt ingestion upon core temperature in healthy men. Hypertens Res 34, 753–757 (2011). Nature link
Phinney SD. Ketogenic diets and physical performance. Nutr Metab (Lond). 2004 Aug 17;1(1):2. doi: 10.1186/1743–7075–1–2. PMID: 15507148; PMCID: PMC524027. Ketogenic diets and physical performance — PMC
Veniamakis E, Kaplanis G, Voulgaris P, Nikolaidis PT. Effects of Sodium Intake on Health and Performance in Endurance and Ultra-Endurance Sports. Int J Environ Res Public Health. 2022 Mar 19;19(6):3651. doi: 10.3390/ijerph19063651. PMID: 35329337; PMCID: PMC8955583. PMC link
Wu, Y. (2023). The role of dietary salt in metabolism and energy balance: Insights beyond cardiovascular disease. Diabetes, Obesity, and Metabolism. Wiley Online Library link
