Hi all! As some of you know, I am a cyclist and currently riding over 100 miles a week (160km). I also do Reformer Pilates and recently added some lifting. You may also know that I live in the devil’s inferno (AKA Las Vegas) and the heat here is no joke (or apparently, it IS…) and it seems no matter how much I try to keep my electrolytes in balance, I keep getting debilitating leg cramps - most times in the middle of the night, but sometimes if I try and sit with one leg crossed over the phone. Sometimes it’s my calf and shin, sometimes it’s my inner thigh and hamstring.
Because it’s hot here and I do outdoor workouts, I take a LOT of salt. I do 1.5tsp of pink salt in water each day (along with ZipFizz), plus I salt my food and often times take sodium/salt pills - 1200-1500mg of sodium each time. (When I get done with a ride, I have a visible layer of salt on my skin that I have sweat out.) ZipFizz has almost 1000mg of Potassium, and I take 600mg of magnesium (citrate/malate) daily.
SO…the big question. Potassium. I eat very minimal vegetables - usually 3-4oz of spinach a day and I can’t eat avocados (food intolerance), so I think I need to supplement further. BUT…how much? All the heart palpitation talk about Potassium has me nervous to add more. Does anyone have hard guidelines on this? Any suggestions from people who have experienced cramps like this?
It is difficult to give you a good supplement dosage without knowing your potassium (K+) levels, Definitely with your activity level, and from your description, you appear to be processing quite a bit of potassium (K+) on a daily basis. Generally in the ICU if I have a patient with a K+ <3.5, I would give 20meq (1,500mg) of oral potassium. If they are on a diuretic we may give 40meq (3,000mg) of potassium. What you have to keep in mind though is that we take daily labs, and these patients are also being monitored via telemetry (on a heart monitor in the room).
To give you general advice without knowing what your K+ level is risky at best, but the recommended daily potassium intake for an average adult is 4,800mg (64meq). So the big question is how much potassium (K+) are you getting from your diet each day. Muscle cramping can definitely be a sign of low potassium, but so can low magnesium levels. The average female only needs about 300mg of magnesium per day, so with your amount of activity 600mg should be enough, but it is hard to say again without having a look at your baseline magnesium level.
So if you can determine the amount of dietary potassium you are consuming on a daily basis (yes I know it will vary some) then you can subtract that from the recommended daily requirement of 4,800mg and start from there to see if this helps with your cramps. If an average adult needs 4,800mg, someone of your activity level and environment may need a slightly higher dose. Research done of endurance athletes running for 40 minutes at 70 degrees Fahrenheit indicated that they lost approximately 435mg of potassium per hour. Making the rate of potassium loss approximately 200 mg/kg of weight lost during exercise at this level.* Obviously you are exercising and living in quite a hotter climate and probably have a higher loss of potassium per hour. I hope this can give you a round about way of how to try and make some safer decisions when supplementing potassium.
*Wenk C, et al. Methodological studies of the estimation of loss of sodium, potassium, calcium and magnesium through the skin during a 10 km run. Z Ernahrungswiss 1993 Dec;(4):301-7.
This is fantastic, thanks! I eat 10g total carbs daily - usually 3-4g in the form of spinach, but that’s probably the only potassium I’m getting outside of suplementation. I don’t eat avocados (allergy) or any other potassium rich food. Based on my fitness pal tracking, it looks like I’m getting around 500mg a day of potassium, before ZipFizz or any supplementation. The last week, I’ve started taking around 500mg on top of that, and have noticeably fewer cramps.
Great, that a small amount of potassium is helping with your cramping. It is a shame that there is not a quick, inexpensive, home monitor that can take a blood sample and test your electrolyte levels. Such a device would help so many people that are on a ketogenic diet. Maybe one day such a device will exist similar to a blood glucose monitor. Such a device would be highly useful in many situations.
