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I know riding and drinking only water can potentially lead to dangerous Hyponatremia or minor issues like muscle cramping. So I often supplement with electrolyte pills in my water like nuun or gu-brew, especially on long rides in hot weather and when doing multi-day tours.

Can too many electrolyte supplements be dangerous? Is there a ratio or formula to follow to make sure I'm getting enough electrolytes, but not too much?

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well worth firing off an email to nuun I would think, and letting us know what they say. I know for Vitamin C you pee any excess, I'm not sure whether that's true for the other ingredients in these tabs. – PeteH Jan 24 '13 at 14:40
up vote 9 down vote accepted

Yes, too many electrolytes can do all sorts of bad things to you.

Good article here:

The U.S. Army has done a lot of research, here's probably the most pertinent paper:

In general, if you are mixing the drinks according to the directions, you won't be too wrong. Most will be a more natural mix if you mix according to directions then dilute 1:1 with water.

Happy Riding.

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If your kidneys are functioning properly the body will eliminate excess amounts of "electrolytes" -- potassium, sodium, calcium, magnesium, etc -- without much difficulty. If you have kidney disease, though, you should discuss the issue with your docs.

Other stuff in some supplements -- herbals, carnitine, etc -- can be harder to eliminate.

And the electrolytes, taken in excess, can behave as a diuretic.

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The diuretic properties of an electrolyte-heavy intake will cause you to become's a catch-22 of hydration. – WTHarper Jan 24 '13 at 19:02
@WTHarper -- True - Taken in excess the electrolytes will make you pee more and become more dehydrated. (Hence, drinking sea water isn't a good idea.) Intake would have to be fairly excessive, though, for this effect to be significant. – Daniel R Hicks Jan 24 '13 at 19:32
Yeah! I would have to imagine that manufacturers of supplements would take into consideration the "more is better" logic, but then again, I don't manufacture much of anything. – WTHarper Jan 24 '13 at 21:22
@WTHarper - Keep in mind that most "supplements" work purely because of the placebo effect. So manufacturers don't have to make the supplements especially strong -- they don't expect them to actually do anything anyway. – Daniel R Hicks Jan 24 '13 at 23:52
I think it's the magic that makes them work (but only if you truly believe.) People have believed in stranger things. – WTHarper Jan 25 '13 at 1:31

I'd recommend you read this series of four articles on hydration and electrolytes from The Science of Sport, the blog maintained by Ross Tucker and Johnathan Dugas. They are two South African sport scientists, disciples of Dr. Timothy Noakes, author of Lore of Running and a respected researcher in all things sport physiology. As an indication, he published the first peer-reviewed paper on exercise induced hyponatremia.

One, two, three and Four. And five and six.

To make a long story short:

  • Hyponatremia is not caused by sweating, but by excessive fluid intake.

  • You should not be worried about what percentage of your body weight you lose to dehydration, but about the osmolarity (concentration of electrolytes) in your bodily fluids is.

  • The thirst mechanism is triggered by changes in the osmolarity.

  • Letting thirst guide what you drink will prevent you from taking too few or too many electrolytes.

  • If drinking by thirst, water will do just fine, as you will restore electrolyte levels to normal levels with dietary intake.

  • The link between cramping and dehydration or lowered electrolyte levels is not really supported by field studies.

So the most sound advice is to let thirst be your guide, and stop worrying about electrolytes.

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Curiously, this contradicts two somewhat common-sense approaches: 1) "you must drink often, if you get thirsty you have already waited too much, and this is bad for you". 2) "only [expensive] BeverAid have the exact electrolyte percentage, pure water is dangerous/bad for you". As a naturalistic person, I think industry claims are very doubtful, but sweat INDEED puts a lot of sodium out, and I think the pure-water approach needs some additional source of sodium in order to work. I drink water and eat salty-sticks during long rides in the summer, it has been working fine. – heltonbiker Jan 27 '13 at 0:02
And, knowing myself AND listening to my instincts (thirst, for example) should solve the "how much / how often" problem. In the other hand, I've had problems with low appetite in the summer, but I'm not sure what's the metabolic / physiological explanation for that. – heltonbiker Jan 27 '13 at 0:04
@heltonbiker From the fourth article linked "body fluids have a sodium concentration of 140mM while sweat has a value of 20-60mM. Therefore when you remove a liter of sweat from your blood, it has much more of an effect on the volume compared to the solutes (sodium), and what happens is that the osmolality rises in response to sweat losses." You really don't need any more Na, unless you are overdrinking. Things do get more complicated if you are also drinking, not eating, the calories to prevent bonking. But you could replace your salty sticks with gummy bears with little electrolyte risk. – Jaime Jan 27 '13 at 0:24
Actually I not always use salty-sticks, but there are times when I CRAVE for them. Usually, I alternate a sweet meal with a salty one (breakfast (sweet) / lunch (salty) / snack / dinner). So, depending a lot on time of day I am riding, I can have chocolate (or other candy) or salty sticks. I guess the really important is to know oneself, and listen to the body. – heltonbiker Jan 28 '13 at 1:05
If you are working hard, it is hot, and you are a salty sweater, you can lose a gram/liter of sweat. Do that for 5 hours, and you have lost 5 grams. If you eat lots of processed food, you might be able to make that up, but if you eat better than that (ie mostly fresh food without a lot of salt), you can easily become hyponatremic. Dealing with hyponatremia through salt supplements is pretty common approach if you read the information on sites like ultracycling. – Eric Gunnerson Sep 6 '13 at 3:56

Here is some information from the nuun website, might help you work out whats best for your body:

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Welcome to Bicycles! While this theoretically answers the question, it would be better to include the essential information in your answer, and provide the link for reference. – freiheit Jan 24 '13 at 19:18

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