What do salt deposits mean?
This might be obvious, but what does it mean when you have the white salt "streaks" on your clothes at the end of a workout? Does it mean you have been taking in TOO MUCH salt? Or not enough??
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This might be obvious, but what does it mean when you have the white salt "streaks" on your clothes at the end of a workout? Does it mean you have been taking in TOO MUCH salt? Or not enough??
Comments
john:
it's not obvious at all. i have seen this question many times in the forums. the answer is: neither.
too much or too little salt would be reflected in a physical symptom, like swelling or cramping. if you have no symptoms, only streaks, then it's just a sign of a normally functioning body and probably more a reflection of weather (evaporating the water in your sweat) or minor dehydration.
you don't need to correct what is not broken in other words or you can get into trouble.
happy training!
gh
Thansk for the response Gilberto. I have experienced cramping during half ironman races but there doesn't seem to be any correlation to the amount of white streaks I see. Sometimes I go for a long bike ride and my shorts are very white, but I don't feel badly at all. Thanks for helping to clarify.
So salt on the shorts/top just means your sweat is salty (duh), it's drying = salt on the kit. Can we learn/say anything about that fact that Timmy's kit is more salty than Sally's? Anything to adjust?
I've always attributed that to the fact that I simply sweat more than most others, and have higher intake demands as a result. I lost 5 pounds in a 70' run' this morning, including taking in 20z of water, and find that I need to take in upwards of 40z per hour on the bike in warm conditions.
I can really only offer my own casual observations on the too much / too little topic, but since I need to drink so much per hour, I tend to favor large quantities of water over any sports drink. This of course is because I don't want, nor could tolerate, the amount of calories / maltodextrin / other sugars that would come with drinking that quantity of Infinit or other drinks. Of course, I could simply dilute the mix that much more, which I have experimented with, but it is very difficult to bring the total amount of nutrition with me I need for a multi-hour ride without having at least one higher concentrated feed bottle. As a result, I feel that I'm flushing out large quantities of electrolytes / minerals by taking in so much water, potentially subjecting myself to hyponatremia.
I think I'm going off topic at this point, but I'm continuing to experiment with this as we have another day with a 113 degree heat index here today. Next up on my agenda for experimentation, salt pills, a topic I discarded as superfluous some time ago and am definitely revising.
Yeah, interested in the same (salt pills) because currently my only source of sodium on the course is Perform, which is also my calorie source. I prefer to race in a low cal range = I may need to supplement that with salt tabs...that's my thinking anyway.
Here is a very straight forward way of thinking about the concept:
total body sodium/total body water: this is measured clinically (i.e. symptoms like edema, mental status changes, muscles not functioning normally);
serum sodium: amount of sodium in liquid part of the blood and this can be measured with a blood test, BUT does not correlate directly with total body sodium. example: dehydration can lead to an elevated serum sodium, but total body sodium can still be normal and you function normally.
the total body sodium/total body water ratio is what matters in terms of our bodies functioning normally. various conditions can affect this ratio, but lets just focus on endurance exercise.
replace what we lose is our job during racing or training. we lose sweat and sweat is more water than salt (i.e. hypotonic). so, we need to put back in a hypotonic solution = powerade or gatorade or perform. the composition of trevor's sweat is no different than Rich's, except that trevor produces more of it. so, Trevor requires more fluids than Rich, but should still be hypotonic fluid.
a caveat: our small intestine and kidneys play a big role in fluid balance as well...
kidneys: besides the obvious function, they also monitor volume. if we get dehydrated and less volume is detected, then they stop excreting sodium at the normal rate. retaining sodium in the blood results in total body water getting shunted via osmosis from the intracellular compartment to the extracellular compartment. this corrects the volume issue, but also starts to increase the numerator of the ratio. also, the lack of sweat due to the dehydration also results in less sodium being lost. NOW imagine you adding salt pills!!! also, realize that if you take advil at an aid station, then your kidneys are being afected even more. the result is swelling and eventual more dangerous symptoms.
small intestine: a significant amount of absorbtion of what we take in gets absorbed here. there is a sodium glucose co-transport that lives here. both these molecules are very important for normal function, but also for endurance racing. optimal absorption of sodium requires glucose. this is why gatorade and drinks like this have glucose. the optimal way to ensure that your salt gets absorbed is to take it with glucose. i don't know of any studies that have measured how much of a salt pill gets absorbed with just water, but i do know the co-transport evolved and stuck around for a reason and for sure is more efficient than a salt pill and water!
Hope this helps.
So, my direct answers are:
Rich: i don't think you can use salt streaks to guide nutrition intake, since their appearance can be influenced by too many factors. your strategy of going minimal with nutrition is VERY GOOD, since it eliminates the factor that can completely screw up your race the most....YOU!!! in other words, the body knows what to do and we are the ones who always screw things up, thinking we know more.
Trevor: more hypotonic fluids should work best and if flavor is an issue, then get a drink with no flavor (infinit) or dilute the commercial ones. the commercial ones are often overly sweet so that people buy them, but as you pointed out, it can upset your stomach. you WILL have more streaks because you secrete more volume.
GH
Ok, awesome, next question: is it a valid recommendation to preload your body with sodium and fluid before a race? That is, It would seem that if I salted my food/drank sports drink beginning about ~48hrs before an event, my body would respond to the increased salt intake by increasing the fluid content of the body? Or does the body just say "you're whack, I'm getting rid of both salt and fluids through the kidneys" while you're trying to preload? I guess the question is can you make your body start the race in a super-hydrated state, as a way to get a head start on the race?
Making small changes in the diet...cutting down on the salt and the streaks should dissapear
Not sure if the science is behind this...but it worked for them :-)
Rich:
the pre-race loading is likely going to have the greatest impact at the sodium blood serum level and overall serum volume level. the total body sodium and water will always equliibrate no matter what, unless there's a defect somewhere. in other words, your total body will think you are wack, but your blood serum will be happy.
if your blood sodium and volume is topped off, then the volume reaching your kidneys will not trigger any sodium retention. the hypotonic nature of a gatorade will introduce just enough sodium to not cause any alrms to go off and the sugar will help to absorb the salt and keep hunger away, so you don't stuff yourself before the race.
we are optimized to function on less, but motivated to want more...this way we stay alive, if we were back in the non trader joes days.
of course, despite this knowledge, i overloaded on the bike and had to go #2 at CdA during the run!!!!
live and learn, but that's what life is all about.
i'm going minimal in my nutrition, like you, from here on in.
GH
just re-read my response and here's a more direct answer:
the idea would be to do no harm in the 48hrs before a race. a properly balanced diet, that correlates well with your activity level in those days is best. suddenly increasing sodium, should be avoided, although your body will probably process it and balance things out by race day...unless u go overboard.
most people don't drink enough water on normal days. on race week, they start to pay attention and drink more. they start adding more salt to things, but that's ok, since they are also adding more water. no harm was done, since the ratio was not affected.
the problem is when you start adding a ton of more salt, or drinking a ton more water and not adding salt. or eating a ton, despite not working out as much during taper, etc.
likely the best approach is to really stay focused on the proper balance all the time, so that in training, you confirm that your intake is well balanced. on race day, with the proper meal early and the sipping gatorade before the start should be enough and then supplementing throughout the race will keep everything optimized.
GH
Awesome, thanks! FYI, I never salt my food, eat very little processed food, other than some bread, mueslix, etc. Rather, I can't recall the last time I picked up a salt shaker...
One thing I have not seen mentioned in this tread is how well the athlete is acclimated to heat. Give me a day or two to find the research but I am confident that one of the key physiological adaptations that comes through heat acclimation is that the salt levels in your sweat reduce significantly!!!
I have seen this in race including Kona where athlete 1 is covered in salt and athlete 2 is not. So in the same conditions, significantly different physiological responses
I am a heavy sweater with sweat tests in ~100 heat index giving 85-96 oz of fluid loss per hour at MP run pace. Early in the season I will get salt on the face and jersey, once acclimated, even at those sweat rates, no salt stains on the jersey. The body given the opportunity to adapt to the conditions conserves the precious electrolytes in hot conditions.
Let me find the research and I will post.
hi Matt, it is mentioned. only instead of heat, i mention dehydration. the decreased volume that comes with dehydration and the kidney retention of sodium is the mechanism for the decrease sodium in sweat in the heat. if you get too dehydrated, then you don't even sweat.
gh
Gilberto - you mention the change in sodium retention relative to dehydration. Yes I agree with that.
sorry, had to answer a question at work...
yes, so we are not saying different things, but your message implies i was not clear.
first: nothing wrong with salt streaks, when there are no symptoms;
second: if you do see salt streak differences between 2 people, then first remember the first point above and then realize that the every body has different rates of sweating or different rates of cleaning themselves with sponges, so they can't be compared.
third: everyone's body will respond the same, unless there is a disease process, in order to keep the total body sodium/total body water at a proper level. in the heat, blood volume gets decreased and sodium is retained, but same thing can happen in the cold if you don't drink enough.
the key is to appreciate the mechanisms driving the body's response to maintain the proper total sodium/toal body water ratio. then our job is to replace what we lose. i wouldn't supplement with too much salt in the heat, because you are already retaining salt due to the decreased blood volume. instead i would make sure to hydrate, check that i have saliva in my mouth, see if i am sweating, check HR: if yes, then i am back at the normal replacement strategy of gatorade and water. if not, then i'll likely be better off drinking more, since my body is already retaining sodium, etc. these checks are more informative than salt streaks.
of course, as you and others have shown, slowing down helps a whole lot, but that's another story.
hope that clears things up a bit.
gh
hi again Matt, you responded as i sent the other message.
so, i think i addressed your point in my last message.
you point out a phenomenon that results in the heat and i point out the mechanism for that phenomenon. the reason the body responds in this way is to preserve function of our cells and organs.
someone who has acclimated to the heat, has allowed for the body to make the necessary adjustments so that total body sodium and water are at the appropriate ratio. day in and day out in the heat and your body adapts and so do you by drinking more water and realizing that you don't need that much more sodium than you think. another person, arrives in the heat and if they understand the body's response to those conditions, then they'll be drinking more, slowing down, and running thru those hydration tests i mentioned (forgot also peeing as one of those tests).
joe schmoe does not understand or forgets and starts taking in salt tabs...if he already has high blood pressure or takes a whole boat load of salt tabs, then he'll start to get swelling all over and if he keeps it up mental status changes.
our diarreah is isotonic, so i will replace with isotonic saline. baby diarreah is hypotonic, so i replace with pedialyte (baby gatorade). replace what you lose.
Rich and others wanted to know if there was anything one can do in the 48hrs before a race to "load up" on salt or if there was anything to be learned from the salt streaks.
so, i don't think we are saying different things, but likely i am really bad at explaining!!!
gh
Gilberto ,
Consume 3,500-4,000 milligrams of sodium 1-2 hours before training with approximately 21 ounces of fluid in 7 portions.
For example, consume 3 ounces of water with 500-571 milligrams of sodium every 10-15 minutes.
Protocol Test #2 (This should be done one week or more after Test #1)
Consume 3,500-4,000 milligrams of sodium 18-24 hours before training. The additional sodium is above your normal intake and can be spread out between 2 - 4 meals or snacks. (Test workout #2 should mimic the same environmental and duration of test #1)
Matt,
as usual, very cool and very thorough.
here are some caveats for people to consider:
-recall that the essential balance of fluids in the body is measured clinically, not by measuring plasma, etc.
-in order for us to have survived so long over time, as a species, the standard error between what is "optimal" is very wide. we are not delicate creatures that need everything at a very narrow window.
i don't have a lot of time to offer my critique of the manner in which these studies are conducted (e.g. how do they accurately measure how much water evaporates in the heat from the skin, the mouth, etc. across different subjects? less water to measure = more salt to measure, etc. i can go on and on), but the good thing is that the two approaches are here as a starting point for those curious to learn more.
my take home message is that our bodies will optimize whatever we put into it, up to a point. if we understand the basic principle total body sodium/total body water ratio, then we simply have to replace what we lose from that perspective, not by what is happening on the surface. this is why i can run fast with salt streaks or without.
there is usually no harm in people concluding from the studies you cite, that salt loading is helpful nor that they can run a better race or train better by following salt streak signs. the body will do what it was designed to do regardless.
however, there is more of a chance of someone screwing up physically AND psychologically if they start freaking out about streaks or that the race site hotel is out of salt. even more sinister of a salt load effect is with the age grouper who has undiagnosed high blood pressure or atherosclerosis or wacked out kidneys.
i too am a scientist (and medical doctor), so don't think i don't appreciate the numbers, i just interpret the data differently.
Be Well!
GH
Let me put a 2X on many of Gilberto’s points. Humans are vary adaptable creatures, given time our systems can deal with an amazing range of conditions with a wide range of nutritional, hydration and electrolyte strategies.