Exercise and fainting?

[El Greco]

El Greco: I'd have to disagree with you that nausea and dizziness are not symptoms of hypoglycemia.

But I didn't say they are not symptoms of hypoglycemia, I said they are much more symptoms of lactic acidosis. Notwithstanding that all symptoms are of course highly individualized (eg I've never felt nauseous or dizzy when hypoglycaemic), it is nevertheless common that feeling so dizzy that you have to sit down and so nauseous that you actually have to vomit are characteristics of the lactic acid "poisoning".

 

[El Greco]

In any case, pure water has a lower concentration of solute than water+anything, and gets absorbed more quickly.

Now, I'm willing to be shown I'm wrong in this, but to date, I've not found evidence of it (a lot of claims from various people selling miracle drinks, but no evidence). IF anyone more knowledgable can weigh in on it, feel free

There are other factors besides osmosis (like gastrointestinal discomfort etc) which make pure water not the best solution. I'll dig up the studies when I get home.

 

[El Greco]

I always avoid manufactured sugar, sucrose or corn syrup containing drinks, plus if you make your own with fruit, you are getting a portion of anti oxidant vitamins and friut sugars or fructoses which are less damaging to teeth than glucose or sucrose.

Just wait and watch me get shot down for these comments!!!!

Well...

I don't disagree, but fructose often causes gi problems in athletes and besides, fruits (especially ripe ones) do contain a lot of glucose themselves.

 

[Doubt]

There are other factors besides osmosis (like gastrointestinal discomfort etc) which make pure water not the best solution. I'll dig up the studies when I get home.

Not sure if I have it right or not, but one of the things affecting the osmosis of water from the stomach is the sodium level in your blood. If you are already low on electrolytes it will take longer to absorb the water in your stomach. Even if your initial absorbtin rate is faster with just water, it won't stay that way.

Ancedote: At Ironman florida in 2002 I was part of a group of 4 people traveling to the race from my club. Two of us did not use salt tablets during the race and the other two did. The two of us that did not use the tablets reported water sloshing around in thier stomachs at the end of the race. (That was after about 12.5 hours of racing in my case.) The other two that did use them did not experience that feeling at the end. Other than the tablets, we consumed similar amounts of Gatoraid, energy bars, etc. Doing another Ironman this year. I will have salt tablets this time.

 

[Doubt]

Well...

I don't disagree, but fructose often causes gi problems in athletes and besides, fruits (especially ripe ones) do contain a lot of glucose themselves.

I have read about the gi problems caused by fructose but have yet to experience them. I often use honey as a cheap replacement for energy gels. The gel packs cost about a dollar for 1.1 oz. I can buy a lot of honey for the same money.

I am not sure if I have either just been lucky or is there some element of adaptation involved.

 

[Hellbound]

There are other factors besides osmosis (like gastrointestinal discomfort etc) which make pure water not the best solution. I'll dig up the studies when I get home.

Cool, I'd like to see them. It may be that I'm misremembering, as well. I knwo this is true for IV fluids (Normal Saline rehydrates faster than any alternatives), but it may be that this does not apply to drinking, and I'm confusing two issues

But I didn't say they are not symptoms of hypoglycemia, I said they are much more symptoms of lactic acidosis. Notwithstanding that all symptoms are of course highly individualized (eg I've never felt nauseous or dizzy when hypoglycaemic), it is nevertheless common that feeling so dizzy that you have to sit down and so nauseous that you actually have to vomit are characteristics of the lactic acid "poisoning".

My fault, then, I misread your statement. Howefver, considering the amount of exercise and that she's on a restricted diet, I'd tend to lean towards low sugar myself. Of course, it's easy enough to test...eat something

 

[Luciana]

I am not sure of terminolgy here, but the clear liquid that comes from the inside of a coconut has some sugars and salts only, no fat.
Fats and oils do not mix with water, you would see a cloudy or muddy drink.

But coconut water can be cloudy and muddy.

The water of a young ("green") coconut is transparent, nearly tasteless (if not slightly salty) and with little to no fat.

The older the coconut gets, the denser the water becomes, and then it's deliciously sweet and cloudy. A single coconut can make you feel bloated if it's old enough. Those are the best. But fatty. You get coconut water in every other corner of Rio.

However if you press the white flesh of the coconut, you get a white milky liquid which we call coconut milk in the UK and this does contain oil.

Yep, that's coconut milk, a staple in Thai food. Very fatty and delicious.

We rely too much on convenience manufactured foods, why eat a food bar, nature makes them for you, nuts, bananas, seeds, sultanas or raisins from california.

When I ride my bike I do not use Gatorade, I drink water and carry fruit.

I consider one of the advantages of living in a tropical country the availability, freshness and taste of fruits. In other countries you get a dozen fruits with multiple recipes. That's fine, and some have a wonderful taste... but around here there are more fruits than I could name, and they keep bringing novel things from China! Walking home from work I pass multiple stands, so I'm always buying stuff. I envy those who can eat while exercising, so if that's you case, then I envy you.

 

[Aardvark]

Hi Luciana,

I am a working class bloke from industrial North England, it takes a lot to stop me eating.

Lads with whom I hyave ridden before have eaten full fry ups of eggs, bacon, sausage with tea and toast within an hour of starting a ride or within an hour of finishing.

By restricting my eating to bananas, apples, plums, peaches etc at least I am trying to avoid an early death from CHD

 

[EHocking]

Nope, it's a bike, because it's underwater, but the strange thing is that both times I felt dizzy some good 30 minutes later (after showering, changing, walking 2 blocks) and it was more than dizziness, it was a distinct feeling of "my legs won't hold me and I'll fall soon".

My wife had this problem, and her trainer pointed out that blood pressure is key to this. Read through this (ignoring the scary stuff about heart conditions and diseases) and you will find that there are a number "conditions" that could be causing this.

Note that I'm not a doctor, nor do I play one on internet, but my wife was recommended to have a quick check by a doctor to determine what was the problem. In a complete flip of "common" knowledge, her blood pressure drops while she's exercising.

In the first instance, I don't think you have to worry, but it is probably a good idea to find out what is causing this condition.

 

[CriticalThanking]

Luciana,

I know you are just looking to drop some weight quickly, but I'd still suggest you get a heart rate monitor and see what is going on during your exercise regimen. It does take a while to figure out what is "normal" for you. There are lots of websites that will tell you all about max heart rates and recommended aerobic ranges, etc. You may find a common thread on days you have the fainting reaction you describe.

If you get serious about regular training, I would even recommend paying for metabolic testing. Find out accurately what heart rates work for you. You may be working far harder than you should. El Greco accurately described working on your lactate threshold. But everyone has a different genetic range/limit to work with. How careful were you in choosing your parents?

I would also second the idea that you experiment with different fuels during a workout. 2 hours is a long time to go with nothing but water. Everyone is different. Some can deal with gels, while others can only take things in true liquid form. I can tolerate most anything, even solid foods on the bike as long as I have not already bonked. But very few gels will, um.... "stay with me" during a run. And you only find these things out the hard way.

CriticalThanking

 

[CriticalThanking]

And I am very jealous of the availability of good fruit there. Congrats.

CT

 

[El Greco]

The voluntary rehydration:

Consuming highly palatable flavored beverages facilitates voluntary rehydration. Voluntary rehydration using three beverages was studied in boys after exercise dehydration during heat exposure: (1) plain water, (2) grape-flavored water, or (3) grape-flavored water containing 6% carbohydrate and 18 mmol * L^-1 NaCl. The flavored carbohydrate-electrolyte drink elicited the largest total voluntary fluid intake (1157 mL), followed by the flavored drink (1112mL), with the smallest volume recorded for plain water (610 mL).

Ok, I quoted the above just for the sake of completeness. Now salt:

Because the kidneys continually form urine, the volume of ingested fluid following exercise must be larger (usually by 25 to 50%) than exercise sweat loss to restore fluid balance. However, unless the beverage contains a sufficiently high sodium content, excess fluid intake merely increases urine output with no benefit to rehydration. Pure water absorbed from the gut rapidly dilutes plasma sodium concetration. A decrease in plasma osmolality, in turn, stimulates urine production and blunts the normal sodium-dependent stimulation of the thirst mechanism. Maintaining a relatively high plasma concetration of sodium (by adding a moderate amount of sodium to ingested fluid) sustains the thirst drive, promotes retention of ingested fluids (less urine output), and more rapidly restores lost plasma volume during rehydration.

Hyponatremia:

The exercise physiology literature contains more than adequate information about the need to consume fluid before, during and after exercise. In many instances the recommended beverage remains plain, hypotonic water. However, we now know that excessive fluid intake under certain conditions may actually be counterproductive, producing a potentially serious medical complication hyponatremia or "water intoxication". Symptoms range from mild (headache, confusion malaise, nausea, cramping) to severe (seizures, coma, pulmonary edema, and death).

The likely scenario most conductive to hyponatremia includes high intensity, ultramarathon-type, continuous exercise lasting for 6 to 8 hours duration, although it can occur in only 4 hours.

...and glucose:

To reduce the risk of hyponatremia in prolonged exercise we recommend refraining from overhydration, that is, do not consume more than 1000mL*hr^-1 of plain water either before, during or after exercise, and add a small amount of sodium (approximately 25 mEq*L^-1) to the ingested fluid. Also, the inclusion of some glucose in the rehydration drink facilitates intestinal water uptake via the glucose-sodium transport mechanism.

Fructose:

Athletes should not substitute exogenous fructose for glucose during prolonged exercise because less fructose oxidizes when equivalent amounts are consumed during prolonged exercise.

Fructose is absorbed more slowly from the gut than either glucose or sucrose, causing only minimal insulin response with essentially no decline in blood glucose. These observations have stimulated debate about whether fructose might be a beneficial immediate pre-exercise exogenous carbohydrate fuel source for prolonged exercise.
Although the theoretical rationale for fructose appears plausible, its exercise benefits remain inconclusive. From a practical standpoint, consuming a high-fructose beverage often produces significant gastrointestinal distress (vomiting and diarrhea), which in itself negatively impacts exercise performance. Once absorbed by the small intestine, fructose must first be transported to the liver for conversion to glucose. This further limits how quickly fructose becomes available for use by the body as an energy source.

There are of course lots of info on ergogenic benefits of carbohydrate feeding during exercise which is not directly related to the issue of rehydration but if you are going to take carbs and water anyway you could as well take them together.

All of the above quotes from "Sports & Exercise Nutrition" by McArdle, Katch & Katch. There are references to studies available for most of the above quotes. If I'm not too bored I'll look later in a couple of other books as well.

ETA: Fluid replacement during and after exercise in the heat.
Carbohydrate and fluid ingestion during exercise: are there trade-offs?
Should carbohydrate concentration of a sports drink be less than 8% during exercise in the heat?

 

[Hellbound]

Cool, thanks.

Makes sense now that I see the mechanisms...although the first link you posted seemed to have more to do with psychology than physiology But the second quote makes some good points. So something in the .9% range seems to be what you're looking for.

Although the hyponatremia seems specific to long-term exercise, but the glucose information in that seems to support the idea that glucose helps out.

I'll bow to your knowledge on this

 

[Dustin Kesselberg]

I find it funny people like El Greco are arguing all of these scientific details about exercise yet looking at his avatar it doesn't look he even exercises!



Did you try what I asked? Whoever posted this thread? Did it work? I bet it did.

 

[El Greco]

Dustin, you have posted a lot of stupid things in reply to several posts of mine and others, but I have let it go so far realizing your diminished intellectual capacity. I remind you the first thread you started on bodybuilding where it is evident that you are not only athletically, but also socially and mentally impaired. I also remind you that I have posted pictures of mine in that thread of yours while you didn't because you were afraid that gays would use them for masturbation material. Need I need remind you the relevant poll as well ? So STFU, dear Dustin, because my patience is not as unlimited as your imbecility. Please don't interpret my reluctance to answer to you in may occasions so far as weakness.

 

[plindboe]

I googled for it but found way too much information and I couldn't wade through those long words. So please keep it simple.

I've been in a 1,200 calorie diet for about 10 days. Quite simple: lean meat, veggies, legumes, fruits and some milk in very small portions. No problems here, I've done this before and it always worked.

Last Wednesday I exercised for nearly 2 hours (water workout + underwater spinning) and about half an hour later I felt dizzy and nauseated. But I forgot about it later. Then on Friday the same thing happened, only this time I got drenched in sweat and was very close to passing out completely. I was in juice shop and looked around to see if there was any hot strong guy to support me if I fell, so that I could sigh and look all delicate and helpless, but there wasn't any, so you see how frustrating the whole experience was. Kidding aside, it's just an overall unpleasant experience and I'm not used to this.

I'm not in any medication and I'm not diabetic or have any heart condition. I had those checked last year when my father had heart problems. That's why it's so problematic to find good info, google just wants to convince me I have to have those to nearly faint after exercise. Oh, and my blood pressure has always been in the normal range.

I gather there is something missing in my diet? Basically, how can I do cardio for two hours without fainting like a Victorian virgin later?

I haven't read the thread, so others have probably provided fine answers already, but here is my reply anyway. I have tried feeling like this several times, it can be rather unpleasant. It's actually fairly well-known and common among people who train seriously. Happens because the body doesn't have enough energy. It's important to eat a decent meal(in your case 400-500 kcal) 1-2 hours before the work-out, with a good amount of carbs(oatmeal, rice, pasta, bread). 2 hours is a long way to work out, so you can supplement with a drink that contains some quickly digestable carbs. Instead of an expensive sports drink, just add some sugar to a bottle of water and drink a little throughout the workout. Not only is it much cheaper, but those fancy sport drinks usually contain much more energy than your body really needs, and isn't optimal during a diet. Just some thoughts, that I hope can help.

 

[Luciana]

Well, update... on Friday I screwed up completely, that is, showed up to work out at 7pm, having had a light lunch at noon, and I was late to think of anything. I thought "guys at JREF can't hear about this" so I rushed into a juice shop and bought papaya+orange+acerola and took half of it before class and the other half in a 10-minute interval I gave myself. So I worked out two hours with no problem. The problem was later when I felt again dizzy and nauseated... but I was home already. Well, it helped that I knew (after some of you used small words to explain to me) that it is not necessarily a bad thing.

On Monday I paid more attention and had a power bar in the afternoon and drank Gatorade throughout the workout, so I was fine.

I swear to Ed I could workout and eat pretty much anything when I was younger. But it could be that now I have a more erratic schedule, so meals are secondary. I'm not much of a planner in a micro-scale.

 

[Dustin Kesselberg]

Dustin, you have posted a lot of stupid things in reply to several posts of mine and others, but I have let it go so far realizing your diminished intellectual capacity. I remind you the first thread you started on bodybuilding where it is evident that you are not only athletically, but also socially and mentally impaired. I also remind you that I have posted pictures of mine in that thread of yours while you didn't because you were afraid that gays would use them for masturbation material. Need I need remind you the relevant poll as well ? So STFU, dear Dustin, because my patience is not as unlimited as your imbecility. Please don't interpret my reluctance to answer to you in may occasions so far as weakness.

Is this post a joke? It must be!


First of all...I am "athletically impared" because I bailed out of a thread that was hijacked by people talking about the size of bodybuilders penis's? I'd like to see the logic behind THAT claim!

Second of all..You post up some photo of a guy who isn't more than 160lbs and looks like he hasn't worked out a day in his life and you get offended and pissy when someone points out the hypocrisy of you giving workout advice? Grow up buddy.



The only one "socially impaired" would be you. Attacking me because I point out the obvious and criticize you. Not only that..But you use some random thread that was hijacked by others as evidence i'm "mentally and athletically impared"?


All I can say at this point is...

HAHA!

 

[rjh01]

What is this? A long running competition to see who can get deepest into the gutter? Because it looks like it. Please do not criticise each other's looks or intelligence. Show how poor the other's arguments are and leave it up to the rest of us to work out who has impaired intelligence and looks.

 

[Gravy]

On Monday I only exercised for one hour and today will be the same, because I'm dealing with the flu.

Workiing out while you have the flu! You're a stronger man than I am! But seriously, THAT sounds like a good way to faint.