What’s Causing My Muscles to Cramp – Q&A

Question: I have been following a very low-carbohydrate diet and taking the ephedrine/caffeine stack for the past 4 months.  Recently I have been having problems with cramping in the gym, I find that if I get too close to failure on a set, I get very bad cramps.  I’m drinking plenty of water and taking a multivitamin and I can’t figure out what’s wrong. Please help.

Answer: Cramping is unfortunately a very complicated topic and while many simple solutions are often thrown out, they don’t always seem to work.   Usually the culprit is issues with hydration per se or electrolyte levels; electrolytes are things like potassium, calcium, sodium and magnesium they are involved in transmission of the electrical signals in the body.  Hence their name.

I’d note that hydration and electrolyte levels are intertwined as the amount of water in the body affects the relative concentrations of the electrolytes in the body. So if there is more water present, the relative concentration of each of the electrolytes will be lower because the water will dilute them.  By the same token, if you are dehydrated, the relative concentrations of the electrolytes goes up.

Most ideas about cramping tend to focus on a single electrolyte, potassium was blamed for quite some time which is the basic origin of the ‘eat a banana to stop cramping’ idea.  Bananas are an excellent source of dietary potassium.

The problem is that cramping is way more complicated than this and can be related to all of the different electrolytes, not simply the absolute amounts of each but the interactions between them.  Fixing the problem often entails trying different things to figure out what’s causing the problems for a given individual.

Now, a potential issue specific to very low-carbohydrate diets (less than 100 grams of carbohydrate per day) and cramping per se is that these diets cause water loss.  As well, the water losses can vary massively from a low of perhaps 1-2 pounds up to 10-15 pounds in larger individuals.    As well, very low-carb diets cause electrolyte losses and this can cause cramping and fatigue.

As I detailed in my first book The Ketogenic Diet, very low-carb dieters need to supplement their daily electrolyte intake with the following at a bare minimum:

  • 3-5 grams extra sodium hydrochloride
  • 1 gram potassium
  • 300 mg magnesium

Not only should this help with cramping issues, this has also been shown to fix some of the fatigue issues that often beset people when they start ketogenic diets.  Of course, an adequate calcium intake is important under all conditions for bone health.  How much you need depends solely on how much dairy foods you’re eating so whether or not you need to supplement extra will depend on that variable.

While you generally have to supplement magnesium separately, you can cover at least some of the potassium and sodium requirements with something like LiteSalt.  This is a table salt that contains 1/2 sodium chloride (standard table salt) and 1/2 potassium chloride.  It tastes just like normal salt but gives a better balance of sodium and potassium.  I’d note that pure potassium salt tends to be a bit bitter which is why I don’t recommend it; most won’t use it regularly.

So the above would be a good first step.  I’d note that empirically high doses of the amino acid l-taurine seems to help with cramps in some people.  If your hydration is good and you’re getting the above electrolytes but are still having problems with cramping, you should consider adding l-taurine to the mix.

I should also mention that stimulants in general and the Ephedrine/caffeine stack (as well as the drug clenbuterol) can cause cramps.  This is even more true on low-carbohydrate diets.  The reason is that they both cause calcium to flow into the muscles, essentially putting them in a low-level state of contraction.  When you put heavy training on top of this, cramping often occurs.   This is likely just an interaction between the low-carbohydrate diet causing dehydration and electrolyte loss, the EC/Clen causing calcium to go into the muscle and then throwing training on top of it.  It’s not very much fun.

I’d note that even for individuals who aren’t on very low-carbohydrate diets, cramping can still occur especially if they do a lot of training in the heat; as well some of the extremist attitudes towards diet such as ‘Never eat sodium’ among bodybuilders and other trainees can cause problems.  Again, this can be related to both hydration and electrolyte imbalance.  Unfortunately, it’s nearly impossible to give more than vague guidelines on this.

Recent research has found that water and salt loss during training can vary about 10-fold between people. This makes giving a specific single guideline (e.g. drink 1 gallon water) impossible even if people try to do it to keep things simple.

At least in terms of training, the old guideline was that you should weigh yourself before and after workout and for every 1 kg (2.2 lbs) of weight lost, you needed 1 liter (32 oz, 4 cups) of fluid to replace it.  This turns out to be wrong, you actually need 1.5 liters (48 oz, 6 cups) of fluid to replace every 1kg of weight lost.

Please note that you don’t have to pound this right after training, but you need to consume that much extra over the course of the day to cover losses.  Athletes who do a lot of training in the heat who don’t replace fluid losses can get into trouble pretty quickly.

As well, note that plain water is actually the worst rehydration drink out there.  As I discussed in Milk as an Effective Post-Exercise Reydration Drink, fluids containing sodium and potassium are retained far better than those that don’t.  Milk also provides good carbohydrates and high-quality protein so it does double duty after training if you can stomach it.

I’d note that, again, weight loss during a given bout of training can vary many fold.  One athlete might lose 1-2 kg (2-4.5 lbs) and another might lose 8kg (17 lbs).  Like I said, it’s impossible to give a specific value of how much fluid to consume because of this.  Weighing before and after for a few workouts will tell you what your personal hydration requirements are.

I’d also mention that sodium losses during activity are just as variable and calculations show that one athlete might only lose a gram or two of sodium during training while another can lose upwards of 20 grams.  I am currently unaware of any non-laboratory way to determine sodium losses during training.

But I also don’t believe in heavily restricting sodium for athletes; training in the heat requires that electrolytes be replaced and liberal use of something like the LiteSalt I mentioned above is a good idea for a number of reasons.

So anyhow, that’s sort of a basic look at cramping.  It’s a place where I wish I could give more firm guidelines but they simply don’t exist.  There is just too much variability and what works for one may not work for another.  In general, it tends to be related to hydration and electrolyte intake and this tends to be more of an issue on very low-carbohydrate diets.  But it can become an issue on carb-based diets as well.

So make sure you’re getting sufficient fluids, don’t skimp on salt (and get a sodium/potassium salt) and consider supplementation if you’re still having issues.  Some people seem more prone to have issues with stimulants as well so if they are causing cramping, you may need to drop them completely.

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