It seems like there are ads for electrolytes everywhere you look, and the more you look, the more ads find their way to your eyeballs. The interest and availability of electrolyte packets has exploded into a $40B industry. The market is projected to double by 2034. However, there are risks associated with overconsumption. A balanced diet often provides enough electrolytes. Looking at my most successful diet of all time (the IVF diet by Zita West), I was regularly getting 1000mg Na from the food, and on some days as much as 3500mg Na. The contributors to high sodium were soy sauce, capers, olives, canned green beans, and shrimp or fish fillets.
Supplements I have or still take (or haven't tried yet)
The items in bold are the things I used during the marathon.
SaltStick Chewables: 100mg Na, 30mg K, 6mg Mg, 10mg Ca, 1g carb
LMNT: 1000mg Na, 200mg K, 60mg Mg, 0g carb
Prime: 600mg Na, 400mg K, 75mg Mg, 10mg Ca, 2g carb
Electrolit: 330mg Na, 370mg K, 20mg Mg, 40mg Ca, 10g carb
Venture Pal: 500mg Na, 280mg K, 20mg Mg, 104mg Ca, 8g carb
Tailwind: 620 mg Na, 180mg K, 24mg Mg, 54mg Ca, 50g carb
Liquid I.V.: 510mg Na, 390mg K, 12g carb
Skratch: 400mg Na, 49mg K, 48mg Mg, 54mg Ca, 19g carb
Gatorade Zero: 380mg Na, 110mg K, 2g carb
Gatorade: 270mg Na, 80mg K, 35g carb
Powerade Zero: 240mg Na, 80mg K, 0g carb
Powerade: 250mg Na, 60mg K, 35g carb
Nuun: 300mg Na, 150mg K, 13mg Mg, 13mg Ca, 4g carb
Solgar liquid: 300mg Mg, 600mg Ca, 2g carb
NOW Ca&Mg softgels: 333mg Mg, 667mg Ca, 25mg Zn, per 2 softgels
365 Ca&Mg capsules: 500mg Mg, 1000mg Ca per 3 capsules
NOW Ca&Mg tablets: 500mg Mg, 1000mg Ca per 2 tablets
TUMS: 1000mg calcium carbonate
Coconut water: 50mg Na, 646mg K, 24mg Mg, 53mg Ca, 15g carb
"Astronaut Juice": 145mg Na, 12.5g carb per 8 oz serving
Coca-Cola: 40mg Na, 42g carb
Pickle Juice shot: 470mg Na, 20mg K, 2mg Zn, 0g carb
Nerds gummy clusters: 15mg sodium, 71g carb
Gu: 55mg Na, 30mg K, 20mg Ca, 23g carb
Clif bloks (3): 50mg Na, 18mg K, 24g carb
Biscoff (4 cookies): 115mg Na, 23g carb
Stroopwafel: 75mg Na, 18g carb
Clif bar: 230mg Na, 225mg K, 40mg Ca, 42g carb
McDonald's salt packet: 280mg Na
Heinz mustard packet: 65mg Na
For me, learning about electrolytes has been a trial-and-error process. When you train with a friend or a group, someone will see you suffering and lean over to whisper about their favorite bonk-breaker. I was told about Gu from a running friend when the mileage climbed above 9 miles for a long run. We would stop to take a gel at mile 7. I remember refilling a water bottle during a 60-mile bike ride in 2010, and someone quietly slipping a Nuun tablet into my bottle. At the time, I was primarily concerned with drinking water, and I thought it was enough to quench my thirst.
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| Marty's Tom's Farms ride |
When I was hiking in the Verdugos, I got food poisoning in 2012 from my own self. I had probably put a Nuun tablet into a hydration bladder and then let it fester. The next time I tried to use it, it was full of pests, which infested my GI tract. I vowed then and there to NEVER contaminate my hydration bladder again. I've heard people put flat Coca-Cola into their water bottles, so I've added Coke for comparison. But I'm too scared of not being able to fully wash it out to put anything other than water in my hydration vest/belt bottles. I remember examining Nuun's ingredients, and in terms of macronutrients and micronutrients, it was similar to the growth medium used to culture fungi.
The kicker for me came when I cramped during the 2024 Santa Monica Classic. I called my sister to complain, and she asked me what type of electrolytes I was taking. When I told her none, she said it was incredible that I lived in such a hot climate and that nobody had taught me about the importance of replenishing electrolytes. To be honest, every time I think about this race, it still burns me that I skipped the 10k and only finished a 5k. The course was shortened due to the heat.
I've been wanting to write a blog about salt for a long time, but it seems like I'm always staying so busy. I had to take a break from grading student work because hackers disrupted our access to the LMS, Canvas. It's been unavailable for just over 24 hours, which is pretty much the timeline I predicted. But it still sucks that I lost about 8 hours of productivity. Although it did give me the opportunity to write and read a little about salt.
What I can say is that during the 2025 LA Marathon, I took two SaltStick chews every 30 minutes and ended up feeling gross at mile 17. I adjusted that to one SaltStick chew every 30 minutes in 2026, and it was perfect. I felt amazing up until mile 25.
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| MyFitnessPal all time data |
LA Road Runners Chat #9 Dietition Serena Marie - Part 2 (10-30-2025)
https://youtu.be/f5gXdJ4i4yQ?si=KmMON9FYyumPI4ux
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| LA Road Runners Thursday Night Coach's Zoom |
You can calculate your sweat rate, and a dietitian who spoke to my running club explained that you should track all of this, including the weather. To convert sweat rate to sodium loss, multiply your sweat volume (in liters) by your sweat sodium concentration (typically 200–2,300 mg/L, with an average of ~950 mg/L). A typical, moderate sweat rate is 1.2 L/h, which, at an average concentration, results in ~1,000 mg (1 gram) of sodium lost per hour. I've never done it, but maybe I can make this a summer project.
Sodium to Salt Conversion: 1 gram of sodium equals ~2.5 grams of salt (NaCl).
Range: Most people lose 200–2,300 mg of sodium per liter of sweat.
Factors: Sweat concentration is mostly genetic, but sweat volume depends on intensity, temperature, and acclimation. You can use this worksheet to calculate your sweat rate, then use that to determine how much sodium you need. I don't feel like I'm a heavy sweater, but at the Naughty Girl Fitness workout, I was dripping sweat, so maybe I just don't notice it when I'm running.
https://koreystringer-institute.media.uconn.edu/wp-content/uploads/sites/3814/2024/08/Sweat-Rate-Calculator.pdf
I am mindful that we need more magnesium as we age. I wonder how much magnesium from supplements is bioavailable. I still take a lot of supplements, pushing calcium and magnesium as I have since pregnancy and postpartum. But because of the cost, I sometimes wonder if I should stop. Also, I wonder if I'm putting myself at increased risk of kidney stones by overdoing it on electrolytes. In all, the body is pretty great at maintaining homeostasis. But I have heard of people overdosing on TUMS and ending up with stones.
I have heard of people taking salt packets from McDonald's, as well as mustard packets. Some people love Nerds gummy clusters. I guess I spent a lot on food/fuel when I was first getting started running, but now that I'm more settled on what I like (what works for me), I don't spend as much. I included fuel and all the food from the race weekend in this calculation. Someone in my running group suggested signing up for ALL the races. Like YOLO. They justified it by saying, "What is your health worth?" And that got me thinking about how much I spent on running in the past few years.
For sure, running has been crucial to my mental health, now and at various previous times in my life. The American Heart Association recommends a sodium intake of less than 1,500 milligrams per day. The form matters. Salt tabs called "buffered" seem to contain sodium citrate, not just sodium chloride. The buffer helps balance lactic acid and possibly other amino acids produced in anaerobic pathways. In fact, some athletes take sodium or potassium bicarbonate prior to intense efforts, such as sprinting.
A future post could explore branched-chain amino acids (BCAAs), another fitness craze, as well as ketones such as beta-hydroxybutyrate. I feel like I'm not interested in doing fasted exercise. I'm trying to fuel while training to avoid dipping into ketosis. What I can say is that I took
BCAA Complex in my smoothies this past training cycle. Not by choice. My son wanted to put them in there because he loved making a rainbow smoothie with many different ingredients. But I did feel a difference in my energy throughout the day. It felt similar to taking a high dose of B vitamins. He also put in
Nature's Superfruits powder (which does have insane amounts of B-vitamins).
Looking at the literature, it seems that a lot has been discovered about metabolism since I left grad school. I remember discovering that ketones and branched-chain amino acids are produced by plants under low-oxygen stress. I'm not saying I'm responsible for these discoveries, but I remember finding these findings and reporting them, and the people in the plant hypoxia world saying it just wasn't possible. Records are being broken every day by athletes who are figuring out better fueling strategies, and I'm sure some of that has to do with electrolytes, too.
I haven't been taking my
collagen powder,
creatine powder, or my
MCT powder supplements in my coffee. For some time now, I've been drinking it black. But I do take a
creatine capsule at bedtime with all my other supplements. Not that you should take my advice. We're all out here doing the best we can. My race results:
https://www.athlinks.com/athletes/85696593/results I'm not trying to win my age group. I am trying to run sustainably so I can continue doing this. It helps balance my mood, and I feel like it's helping me ease the menopause transition.
One strange thing I did notice was: I kind of feel like my belly fat is decreasing now that the marathon is over. It's been two full months now. I feel like longer walks, lower stress, and more cross-training are actually making a big difference. I started running to get rid of the belly fat and lose weight. But running long distances hasn't really lowered the number on the scale much. I'm trying to revisit the idea of cortisol. Doing workouts that raise cortisol will increase belly fat. Doing workouts that lower stress may actually have a larger impact in the direction I would like to go.
I've been enjoying the off-season, following the Fit4Mom 5k plan A, which is really chill. I've been doing Royal Core 4.0 from RunFitMama and some workouts here and there from Naughty Girl Fitness. I am thinking that the long walks and some weight lifting are revving up my metabolic engine. I think I might need to keep lifting heavy shit. I'm in pain every day anyway, from my joints aching. Why not add some muscle soreness? Dietarily, I've tried to reduce my intake of fried foods and increase my intake of dietary fiber from fruits and vegetables.
My previous posts about salt:
Other References:
The use of buffered salts as anticoagulants for the maintenance of true cell volume and for the determination of plasma proteins. Chorine, V.
Revue d'Immunologie (1940), 6, 193-208.
Magnesium: Exploring Gender Differences in Its Health Impact and Dietary Intake
By: Mazza, Elisa ; Maurotti, Samantha ; Ferro, Yvelise ; Castagna, Alberto ; Pujia, Carmelo; Sciacqua, Angela ; Pujia, Arturo; Montalcini, Tiziana.
Nutrients (2025), 17(13), 2226.
Magnesium in Obesity, Metabolic Syndrome, and Type 2 Diabetes. Gabriele Piuri, Monica Zocchi, Matteo Della Porta, Gian Vincenzo Zuccotti, Luciano Pinotti, Valentina Ficara, Michele Manoni, Jeanette A. Maier and Roberta Cazzola. Nutrients (2021), 13, 320.
Perspective: Ketone Supplementation in Sports—Does It Work? Pedro L Valenzuela, AdriΓ‘n Castillo-GarcΓa, Javier S Morales, Alejandro Lucia.
Adv. Nutr. (2020) Oct 22;12(2):305–315.
Effects of a commercially available branched-chain amino acid-alanine-carbohydrate-based sports supplement on perceived exertion and performance in high intensity endurance cycling tests
Marco Gervasi, Davide Sisti, Stefano Amatori, Sabrina Donati Zeppa, Giosuè Annibalini, Giovanni Piccoli, Luciana Vallorani, Piero Benelli, Marco B L Rocchi, Elena Barbieri, Anna R Calavalle, Deborah Agostini, Carmela Fimognari, Vilberto Stocchi, Piero Sestili.
J Int Soc Sports Nutr. (2020) Jan 20;17:6.
