electrolytes for humans

["Beth Glace" <lb@nismat.org>]

I've been meaning to respond to this for a few days now, but we're 
just finishing up some research on dancers,  which is to be presented 
next week.  Big rush to make slides, ahhh!!!
SO, now to switch mind set to endurance and electrolytes.  What you 
drink is very much tied into what electrolytes you choose.  Remember 
that humans have a much more dilute sweat than horses, and that our 
sweat has less electrolytes in it than the blood does.  This means 
that when we sweat it serves to pull comparatively more water than 
electrolytes from the blood, and the blood become very concentrated 
or hypertonic.  Eventually this will trigger thirst, and the problem 
will begin to correct itself.  So, loading up on a lot of 
electrolytes should always be followed by a lot of fluid.  

Now what kind of fluid.  If you are not doing a lot of fast  running 
you can probably do very well with a very concentrated beverage like 
Ultra Fuel.  We did a study a few years back with this product and I 
can tell you that it does not supply much potassium and provides 
about 20% of its volume in carbohydrates.  This can make it a bit 
unpalatable, as it can appear as almost a slurry. The cyclists in our 
study tended to end up with very low blood potassium levels after 
drinking it, since potassium follows the sugar out of the blood and  
into cells.   But if you like it, fine. Better to find something you 
like drinking than to not drink enough.   If you are doing alot of 
running or heavy physical exertion you may find that such a 
concentrated product may cause some nausea and diarrhea since they 
are absorbed more slowly from the intestines.  Play around with it in 
training and see what works. Remember that the first priority is 
fluid, the second is probably the energy source or carbs, and next is 
electrolytes.  Most sports drinks are formulated with this in mind.  

Beth Glace
Sports Nutritionist
Nicholas Inst. Sports Medicine and Athletic Trauma
NY, NY