Isotonic drinks

[crays]

Hi guys, i am not sure if its here i should post this but couldn't find a better category.

Just wondering, after exercising, we're often thirsty and drinking isotonic drinks is better than drinking normal water, why is that so?

[Monique]

During exercise you loose electrolytes through transpiration, by drinking isotonic drinks with electrolytes you restore your body's supply. Also, the isotonic drink will maintain the osmolality of your blood, so that less urine is produced (making the rehydration more effective).

[crays]

Then would normal water with additional of salt have the same effect ?

[negitron]

http://www.livescience.com/health/090519-bad-sports-drinks.html

The primary function of a sports drink is to hydrate the body. Depending on your body weight, you might lose a quart or two of water per hour of exercise through sweating. A sports drink contains water, electrolytes (such as sodium and potassium lost in sweat), and sugar, euphemistically referred to as fuel.

Plain old water is fine for hydration when working out for less than an hour or even biking casually for two hours. Your body has enough fuel and electrolytes to last this long. Water is in fact superior because it contains zero calories. Gatorade contains 50 calories per 8 ounces of fluid, and bottles typically contain 20 to 32 ounces. So, to burn off those additional 125 to 200 calories, you'll need to run an extra mile or two.

Bottom line is if you're engaging in light to moderate exercise for under an hour or so, an isotonic sports drink is unnecessary. There is also evidence that overconsumption of sports drinks (exacerbated by their pleasant flavor) can contribute to excess hydration resulting in a potentially dangerous condition called hyponatremia:

http://adisonline.com/sportsmedicine/pages/articleviewer.aspx?year=2005&issue=35100&article=00005&type=abstract

The present review demonstrates why fluid overload predominates over electrolyte loss in the aetiology of exercise-associated hyponatraemia (EAH), and why the excretion of electrolyte-dilute urine is highly effective in correcting EAH (nonetheless, loss of sodium and potassium is significant in long events in warm weather). Sports drinks will, if overconsumed, result in hyponatraemia. Administration of a sports drink to an athlete with fluid overload hyponatraemia further lowers [Na+]p and increases fluid overload. Administration of either a sports drink or normal (0.9%) saline increases fluid overload.

[crays]

Thanks for the info :)

[f95toli]

If it usually a good idea to add some juice to the water to give it some taste. The reason is simply that it will make you drink more; most people will simply not drink enough fluid to get properly re-hydratet otherwise.
The fact that sports drinks make you drink more (and sometimes even make you a bit thirsty) is one reason why they are often more efficient than water.

But other than that I agree with what has been said above; unless you are exercising for over one hour isotonic drinks are probably not necessary. The one exception might be if it is really warm and you are sweating a lot.

[liannagreyson]

Thanks. very helpful post. I read a few of your other posts and they all helped me.

[Andy Resnick]

Not yet mentioned, there is a sodium-glucose transporter. So, in order to more efficiently absorb glucose, it helps to add some salt.

[Moonbear]

If it usually a good idea to add some juice to the water to give it some taste. The reason is simply that it will make you drink more; most people will simply not drink enough fluid to get properly re-hydratet otherwise.

That's generally a myth. Most people drink plenty, and often far more than they need to drink to remain hydrated. Unless you're ill, or working out for a long time in the heat, as long as you drink when you're thirsty, you'll be fine.

Here's a simple test if you're concerned you may be dehydrated. Pinch the skin on the back of your hand into a little tent. If it immediately returns to normal when you let it go, you're hydrated. If it stays tented when you let it go, or returns to normal slowly, you're dehydrated.