Sports drinks

[eardstapa]

Interesting how in the Panorama programme they showed Tim Noakes laughing at length at the idea of zero calorie electrolyte replacement drinks, whereas in The Lore of Running (by Noakes) there is a long detailed section on the importance of replacing sodium lost through sweating (4th edition, pp 213-217).

Summary: sodium determines the level of water in extra-cellular fluid; if you lose a significant amount of sodium through sweating and then just drink plain water, excess water is excreted to maintain proper osmolality - ergo, you still end up dehydrated. Therefore electrolyte supplements (eg Nuun) have a role to play.

I think the programme both misrepresented/oversimplified the scientific view and - perhaps more importantly - didn't really give much weight to people's actual experiences beyond setting up a few vox pops coming out of a gym to look like gullible stooges. They did this so they could present a sensationalist picture of credulous consumer-drones being duped by big corporations (again!). Muddled and without much room for nuance.

[Mike T]

Interesting how in the Panorama programme they showed Tim Noakes laughing at length at the idea of zero calorie electrolyte replacement drinks, whereas in The Lore of Running (by Noakes) there is a long detailed section on the importance of replacing sodium lost through sweating (4th edition, pp 213-217).

Summary: sodium determines the level of water in extra-cellular fluid; if you lose a significant amount of sodium through sweating and then just drink plain water, excess water is excreted to maintain proper osmolality - ergo, you still end up dehydrated. Therefore electrolyte supplements (eg Nuun) have a role to play.

I think the programme both misrepresented/oversimplified the scientific view and - perhaps more importantly - didn't really give much weight to people's actual experiences beyond setting up a few vox pops coming out of a gym to look like gullible stooges. They did this so they could present a sensationalist picture of credulous consumer-drones being duped by big corporations (again!). Muddled and without much room for nuance.

I think Noakes laughed because the discussion at the the time had mainly been about energy drinks. The electrolyte concentrations in most sports drinks are far too low to differentiate them from non electrolyte containing drinks in any way other than taste - in particular they do not reduce the risk of hyponatremia.

Under conditions of stress - marathon running/fell running/triathlons/multiday events - the body ignores osmolarity and retains water so that if excess water is taken in hyponatremia results. Supplements such as Nuun do have a role to play, though "most people" who become hyponatremic are mainly or purely water overloaded, rather than salt depleted. "Most people" have been poorly advised about fluid intake, and are not used to the long days out in the hills that most fell runners cope with easily.

Such programs are by definition simplistic, and have to be a bit sensationalist to get an audience - it was still interesting to see that others have not been able to find a scientific justification for most of these heavily marketed products - many will have held this view for some time, but of course there is a tendency to look for that which confirms an already held point of view, and ignore that which doesn't.

[noel]

but of course there is a tendency to look for that which confirms an already held point of view, and ignore that which doesn't.

Good post. That's exactly what I was thinking.

[eardstapa]

"Most people" have been poorly advised about fluid intake, and are not used to the long days out in the hills that most fell runners cope with easily.

Quite true. I think I fit into a somewhat broad and indeterminate margin between "most people" and the chosen few proper hard men () and am probably too willing to try anything that might make me feel a bit less like crap than I do after a few hours. Thanks for explaining that bit about the body ignoring osmolarity under stress; very interesting (I shall remind my own body which continues to sweat profusely and saltily long after I wish it would stop!)

[Glen222]

Sports drinks may be useful for the moment but using them on a regular basis is not a good choice. Energy drinks contain high sugar and caffeine value and may be bad for your fitness. But for heavy runners the situation is little bit different because they need some quick energy after running...

[zephr]

For those of you that are interested in the up to date knowledge on hydration, sports drinks etc, noakes has a new book out on it.
It's got pretty much all the recent studies and reviewed papers on hydration, and a fair amount of discussion as well. Not got hold of a copy yet, but its been highly recommended to me.

It's called waterlogged : the serious problem of over hydration in endurance sports
http://www.amazon.co.uk/Waterlogged-...2755475&sr=1-1