Electrolytes: Nature's Little Enablers Layne Wallace

This appeared in the = newsletter for the Hammerhead Triathlon Club
Some = material has been added or modified because of comments received after the original article = was published

It's usually a mistake to spend a lot of time on one aspect of athletic endeavor because it's all tied together - the Zen of sports. One aspect of physical activity has an effect on some other aspect. Only those who are = truly enlightened are able to think of the whole without thinking of the parts. I ain't one of 'em. So, here goes with electrolytes.

Electrolytes are amazing little compounds when used in a human body. They are even more amazing when the human body runs out of them. Basically, the electrolytes that interest athletes are salts. There are many different = kinds of electrolytes but athletes tend to focus on just a few. While sodium is = the electrolyte that gets the most press, three others play a significant role = in endurance activities: potassium, calcium, and magnesium. The primary = purpose of electrolytes is to make the muscles work (OK, OK, there's more to it but = this isn't a biology paper). When the electrolyte balance gets upset, the muscles get upset. When the electrolyte balance gets really upset, brain function doesn't - function. More on this later.

Electrolytes need to be replenished because the body uses and loses = them on a regular basis. The obvious way we lose electrolytes is through sweat. The more we sweat the more electrolytes we lose. Body fluids and the water in = them interact with electrolytes to the point where we can't really talk about one without talking about the other. Another way to think about it is that electrolytes are dissolved in the fluids so where the fluids go, the electrolytes tend to go.

For example, dehydration is often considered just the loss of water = from the body. However, that fluid loss also affects the electrolyte balance since electrolytes are also lost with the fluids. When our electrolyte supply gets low, the muscles can no longer work smoothly so they tend to overreact = (cramp). As we lose more electrolytes the muscles' function will start to degrade and require more glycogen to contract and release leading to a bonk. At the = extreme end of electrolyte loss, muscle control is lost and brain function is = impaired (potentially causing convulsions and worse). The extreme loss of = electrolytes will cause more than just muscle cramps.

If we only replace the lost fluid with water we get hyponatremia. Hyponatremia is obviously dangerous because the balance between water and electrolytes has become way out of whack. The fluid in the body doesn't have the necessary concentration of electrolytes so our body will try to retain fluids. This means sweating stops. When sweating stops our core body temperature goes up. "The electrolyte bone connected to the sweat bone. The sweat bone connected to the body temp bone." The opposite (too much electrolyte) is called hypernatremia (and other things depending on the electrolyte). In extreme cases this can cause kidney problems. =

The amount of electrolyte loss depends on the person's natural loss/retention rate, the amount of sweating, the weather conditions, and the electrolyte levels at the start of the activity. That last one is usually = the wild card. Bottom line: Electrolytes HAVE to be replaced after 'short' activities and during 'longer' activities.

Back in the day, we used NaCl tablets (table salt) and water. Because we were dumping a load of salt on a stomach under stress, stomach problems were common and fueling during endurance activities was compromised. Today we use three primary ways to replace electrolytes: salts provided in fluids (sports drinks), salts in nutrition (gels and bars), and electrolyte supplements. =

As a general rule, sports drinks do not have enough electrolytes to see = us through 'longer' sports activities. For someone in Florida in the summer who sweats efficiently, 'longer' is anything over 45 minutes and certainly = anything over an hour (the amount of time you sweat tends to trump the effort = during the sweating). While some sports drinks provide more electrolytes than others, = the important question is, "Is it enough?" The answer is usually, "No." The same is true for gels and bars. Several years ago a bar came out with enough electrolytes to be beneficial - very few people could = eat it. The key seems to be getting the electrolytes past the taste buds without upsetting a stomach under stress. Electrolyte supplements attempt to do just that.

Electrolyte supplements come in tablets, capsules, and powder. The powder seems to be out of favor right now since it's difficult to get the powder = past the taste buds. The best form of the electrolyte delivery varies from = person to person. For example, some people have no problem whatsoever with capsules during a strenuous physical activity while other people tend to gag on them. The only way to know is to try them during a strenuous training session = (that's why we train). There are also a small number of people who can tolerate = large amounts of salt so they open the capsules and dump them into their sports drinks. This technique definitely needs to be tried before a race and not during.

Electrolytes, like carbohydrates, have a limit on how much the body can replace in a given time period. The basic rule of thumb for a 6% = carbohydrate liquid absorption is about 2 liters per hour. Any more fluid can cause = stomach distress and a possible DNF. Studies have found that combining sodium with carbs (some suggest that maltodextrin and sucrose are absorbed more = efficiently than glucose or corn syrup) actually helps absorption of water, carbs, and sodium. However, the amount of effort affects the amount of absorption the = body can do. The more the effort the less the absorption. Actually, this is still being debated among the sports physiology people but the wise move is to = err on the cautious side and assume it's true.

"OK, so what? All of this bio-waffle is fine but what do I need to = do about electrolytes?" Good question. Glad you asked. First disclaimer: = The following recommendations are based on existing literature and personal experience. The literature is there for anyone to read. However, the = personal experience has to be earned by each individual. Second disclaimer: I'm not a physician (although I did play one in grade school fairly often). Third disclaimer: I have no ties to any of the companies discussed below (but I'm willing to discuss a kickback).

For longer activities, use a sports drink with an electrolyte = supplement and consider a carbohydrate supplement. All right, it's not a big news flash. = The real trick is the form and the amount of electrolyte. As with carbs, one = main issue is getting the electrolytes to the stomach (and small intestine). If = you can't easily swallow a capsule, then don't use capsules. Consider using a tablet that dissolves in liquid. Finding the right form of electrolyte replacement just takes some practice.

The amount of electrolyte is a much more difficult problem. The amount of replacement depends on the amount of loss. During hot days with large = efforts, we need more electrolyte replacement than in light workouts on cool days. = For activities lasting less than an hour, sports drinks will provide enough = electrolytes. However, for events lasting over an hour and half, sports drinks don't even come close. Noakes =5Bpause for reverent silence=5D suggests starting with = at least 200mg of sodium per hour and going up to 900mg of sodium for ultra = distances. Ultramarathoner Ann Trason was able to get by with only 200mg of extra = sodium per hour but she also used very salty foods during events. Most people are = not able to tolerate 900mg of sodium per hour. The rule of thumb at the USA = Olympic Training Center in Colorado Springs is 600mg per hour for endurance events longer than 2 hours. So, the recommendation proposed here for activities = over 2 hours is 600mg of sodium per hour. Let's put it all together. =

If we are using a sports drink like Cytomax (other drinks will work in a similar way as long as you are able to drink two bottles an hour without gagging), we're getting 120mg of sodium (along with other electrolytes) = per 16 ounces. If we drink two 16oz bottles an hour (roughly 2 liters), we're = getting 240mg of sodium per hour. All we need is another 360mg of sodium from a supplement. We've left out any consideration of plain water bottles or nutrition. That can be in our next episode.

Let's look at some current electrolyte supplement products. A note of caution: Companies rarely keep the same formula for very long (the = exceptions like Succeed Caps=21 are rare) so be sure to double check the amount of electrolytes in the dosages of your supplement. I found 43 different = brands of electrolyte supplements before I stopped looking. The following list is = based on discussions in online endurance sports forums.

Brand	Delivery	Dose size	Sodium	Potassium
Succeed	Capsule	1 cap	341mg	21mg
Hammer Endurolytes	Capsule	1 cap	40mg	25mg
Zone Caps	Capsule	1 cap	51mg	14mg
Salt Stick	Capsule	1 cap	215mg	63mg
Nuun	Tablet	16oz/tab	360mg	100mg
Zym	Tablet	16oz/tab	250mg	50mg
CamelBak	Tablet	24oz/tab	410mg	70mg
Elete	Powder	32oz/.5tsp	125mg	130mg

There are two philosophical approaches to electrolyte supplements: small amounts taken often (Hammer Endurolytes) or large amounts taken less often (Succeed S=21Caps). Both are valid approaches for different people. You = need to consider your hydration techniques to choose the right one for you. There = are several ways to determine if your electrolyte level is OK. Unfortunately, = most require the services of a biolab. Cramps are one way to estimate electrolyte need but remember that there are several other ways cramps can occur. If you tend to have cramps on every long activity then examining your electrolyte intake is highly recommended.

Sources

While preparing this article I checked the Web for a table to compare different electrolyte products. Not surprisingly, the Web sites with tables were all supporting a specific product and had omitted or mistyped info = about their competitors. Here's one that has a goodly number of products. =

http= ://www.saltstick.com/products/sscaps/ccompetitors.htm

I also checked for online articles to make sure I wasn't duplicating something that already existed. The articles I found seemed to be either physiology journal articles, "drink before you're thirsty" = articles, or articles written by dogs while their owners were away. As such, the following resources are books.

If you could only have one resource about the practical physiology of sports, I'd suggest
Noakes, T. 2003. Lore of Running. Champaign, IL: Human = Kinetics.

There are actually some very nice books about sports nutrition = available. I grabbed the top three from my stack assuming that I use them more than the others.
Eberle, Suzanne G. 2007. Endurance Sports Nutrition. Champaign, IL: Human Kinetics.

Fernstrom, Madelyn H. 2005. The Runner&=238217;s Diet. = Emmaus, PA: Rodale. (Yes, it surprised me, too, that it is that good.) =

Clark, Nancy. 2008. Sports Nutrition Guidebook. Champaign, = IL: Human Kinetics. (No, I'm not getting paid by Human Kinetics - they just = put out good books.)

Lastly, just because &=238230; Burke, Edmund R. 2002. Serious = Cycling. Champaign, IL: Human Kinetics.

 

Debi Bernardes

USAT Level 2 Coach

USAC Level 3 Coach

8385 Tomahawk Drive

King George, VA 22485

(540) 709-1484