Sports Drinks & Athletes don't need sodium or protein

[jared]

I subscribe to Joel Friel's blog and found the following post that was sent to me on Question on Sports Drinks very interesting. I'm not changing my nutrition right now before IMLP but it's interesting to think about.

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Question on Sports Drinks
Posted: 01 Jul 2009 07:03 AM PDT
I just received a great question from a coach about what he should tell the athletes he coaches about sodium and protein in sports drinks during long events such as Ironman. Here is my reply...

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I’ve been doing a lot of reading in the literature and talking with informed people regarding, especially, sodium. I’m coming to the conclusion that sodium is not necessary during exercise for all of the reasons we have previously been told were so critical - cramping, coping with heat, and maintaining pace/power. I can find no good evidence to support any of these. Just a lot of opinions and sports drink marketing stuff (which most athletes have come to accept as factual).

That said, sodium is beneficial in the transport of water across the intestinal mucosa in the upper intestine where it is absorbed. In other words, with a bit of sodium in the drink you get more water into the body. That may be beneficial to performance if there is a real risk of excessive dehydration (which is far too often blamed for poor performance). As I’ve mentioned before, the most dehydrated athlete in the race is typically the winner. But this is a whole other discussion.

Is protein necessary or even beneficial in a sports drink? The research is murky on this still. However, there is something called “central fatigue” which has to do with the central nervous system experiencing the need for sleep during extended exercise. This seems to be related to circulatory branched chain amino acid status. A couple of studies have suggested that taking in protein during or before exercise may prevent this. But the condition seems to be quite rare. Interestingly I spoke with an athlete a few days ago who did an Ironman and felt like he just wanted to lay down beside the road while in the bike leg and take a nap. This may have well been central fatigue.

What do I do? I eat well before starting a workout. Then I drink water only when thirsty on very long rides and carry carb products such as gels and bars in my pockets. They have a small amount of sodium and negligible protein. Water-only works fine for the first two hours on long, easy to moderately hard rides for me. Then I start taking in carbs along with the water. For example, last week I rode over 500 miles in the Colorado mountains with thousands of feet of moderately hard climbing every day. The average duration was nearly 5.5 hours a day for 6 days. I did just what is described above and never experienced the least bit of problems.

But that was an n=1. Individual athletes may well have unique needs I don’t have for any number of reasons. Some experimentation (with an open mind) is necessary to discover what works. The problem is that most athletes have been so inundated with marketing hype (much of it from “science”) that they can no longer think critically.

I tell the athletes I coach that if they want to use sodium during exercise that’s alright. I know of no downsides (although there may well be some we don’t know about yet such as balancing potassium and sodium, and inter- vs intracellular fluid levels). The same goes for protein. It’s up to them if it has worked ok in the past. If they have had digestive tract problems such as nausea or the gut “shutting down” then I suggest omitting the protein.

Generally, I have come to believe that we need far less “stuff” in our guts during exercise than we have come to believe over the last 30 years. The only two things that seem to stand the test of time are water and carbohydrate. And it’s quite possible to be excessive with both of these.

I hope this helps a bit. I wish I could tell you without question that what I’m suggesting here is irrefutable. It’s where my head is right now on this subject. Time marches on.
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Interesting...

[johnny5]

I read that article too. My coach (USAT Level 1) is doing more research into the matter, but isn't convinced. He's also going to talk to his boss who is a Level 3 coach. Personally, I'm sticking with my nutrition plan of taking in more salt since it seems to be working for me.

[jared]

Let me know what you find out. I agree that I'm not changing my plan right now either. He also states that he doesn't see an adverse reaction to salt intake so it may just not help. I would like to see some studies into that and into protein intake.

I believe it also comes down to what works for you.

[jared]

Also, I'd like to ask the question about hyponatrinia (sp?) where you have too much water and not enough salt. Is that just an extreme case that doesn't relate to smaller amounts of intake of water? Are we just told that we need to take salt so that we can guard against drinking copius amounts of water and dying?

I'm sure that you've also heard of someone that has had issues cramping in the latter parts of races only to take salt caplets the next race and not have issues. Coincidence or is there something there? Too many questions?

[holli81]

Yes, hyponatremia is a real problem -- especially exercise-associated hyponatremia (EAH). In fact, there is a medical conference dedicated to this issue alone. I know the author doesn't believe all this "science", but I gotta tell ya, I'm a strong believer! Information that came out of the conference is that sodium levels are dependent of MANY different factors.

1. Well trained and more fit athletes tend to sweat more in volume than new and under-trained athletes. However, the sodium content of the sweat is MUCH less in well trained athletes. So I guess we can chalk this one up for the author with his hypothesis that endurance athletes might not need as much sodium replacement.

2. Hydration. This is probably the biggest factor right here. In recent studies, it was shown that most athletes tend to over-hydrate. When you consume more water, it will dilute the electrolytes already in your blood. This will cause hyponatremia not because too much was lost, but because it is too dilute. According to the EAH conference, endurance athletes (described as those with at least 7 hours of continuous exertion) should rely on their "thirst sensors". In other words, only drink when your body says to drink. One way of preventing over-hydration in races is to offer water less frequently -- this tactic has already been used in many races, including the Boston marathon where water stations are every 5k instead of 1.5k. When fluid is consumed, there isn't a difference between plain water and sports drinks like Gatorade. Although Gatorade does have sodium and potassium in it, it is a grossly low amount so that the net effect is to absorb more water and actually none of the electrolytes. What does this do? Worsens the hyponatremia! ...so I guess this point can also be chalked up to the author in that just plain ol' water is good enough. HOWEVER, it is the AMOUNT of water that should be taken into consideration.

3. Another factor is the natural hormones in our body that tell our kidneys not to excrete so much water (i.e. urine). Many factors were recognized that increase the amount of this hormone in athletes, so by that fact alone, athletes do not need to drink as much fluid as commonly recommended.

So basically, hyponatremia is a HUGE issue with athletes (Jared, you were right in that if sodium is too low, a person can have some serious and irreversible damage or even death if not corrected appropriately) and fluid consumption during exertion really ought to be re-evaluated. The biggest factor is hydration. The author claims athletes don't need sodium replenishment but this really varies from person to person. The real issue is not sodium replenishment, but appropriate water replenishment. If you are one to drink fluids constantly while working-out, then salt tablets would be good for you. If not, then just listen to your body and drink when it says to drink. Although, I don't think anyone doing IMLP should experiment at this point. If, at the end of the race, you feel like you may have hyponatremia (weakness, dizziness, headache, nausea and/or vomiting), you should seek medical attention right away. The EAH conference recommended that the medical tents at races have proper equipment to test your sodium levels, so I would hope that most of the IM medical tents would have them.

I think I'm rambling now. Sorry. I'm not sure if I helped or made things more confusing, but if anyone wants a copy of the article I read, I'll be more than happy to share it (I think I can download the article and email it, otherwise I will have to give it to you via hard copy).