cnighbor1
07-30-2012, 04:10 PM
Do Sports Drinks Really Work?
—By David Tulle
Just in time for the Summer Olympics in London, a top science journal has issued
a blistering indictment of the sports drink industry. According to the series of
reports from BMJ (formerly British Medical Journal), the makers of drinks like
Gatorade and Powerade have spent millions in research and marketing in recent
decades to persuade sports and medical professionals, not to mention the rest of
us suckers, that a primal instinct—the sensation of thirst—is an unreliable
guide for deciding when to drink. We've also been battered with the notion that
boring old water is just not good enough for preventing dehydration.
I've been as susceptible to this scam as anyone else; I knew, or thought I knew,
that if I'm thirsty after my half-hour go-round on the elliptical trainer, it
means I was underhydrated to begin with. So for years I've been trying to
remember to ignore my lack of thirst and make myself drink before working out.
Not any more.
The BMJ's package of seven papers on sports performance products packs a
collective wallop. The centerpiece is a well-reported investigation of the
long-standing financial ties between the makers of Gatorade (PepsiCo), Powerade
(Coca-Cola, an official Olympic sponsor), and Lucozaid (GlaxoSmithKline) with
sports associations, medical groups, and academic researchers. It should come as
no great surprise that the findings and recommendations that have emerged
through these affiliations have tended to include alarming warnings about
dehydration and electrolyte imbalance—warnings that conveniently promote the
financial interests of the corporate sponsors.
And who knew there was something called the Gatorade Sports Science Institute?
According to the BMJ investigation, "one of GSSI's greatest successes was to
undermine the idea that the body has a perfectly good homeostatic mechanism for
detecting and responding to dehydration—thirst." The article quotes the
institute's director as having declared, based on little reliable evidence, that
"the human thirst mechanism is an inaccurate short-term indicator of fluid
needs."
Another study in the BMJ package finds that the European Food Safety Authority,
which is authorized to assess health claims in food labels and ads, has relied
on a seriously flawed review process in approving statements related to sports
drinks. A third study reports that hundreds of performance claims made on
websites about sports products, including nutritional supplements and training
equipment as well as drinks, are largely based on questionable data, and
sometimes no apparent data at all. One overall theme emerging from the various
papers is that much of the research cited was conducted with elite and endurance
athletes, who have specific nutritional and training needs; any such findings,
however, should not be presumed to hold for the vast majority of those who
engage in physical activity.
Critics have long blasted sports drinks as being loaded with calories and
unnecessary ingredients. (Not to mention concerns about the environmental costs
of producing, shipping, and discarding all those millions of plastic bottles.)
Yet the product category represents a lucrative and growing market, with US
sales of about $1.6 billion a year, according to the BMJ. In fact, Powerade is
the official sports drink of the London Olympics, and Coca-Cola is hyping the
brand with a campaign featuring top-tier athletes.
The BMJ papers address two related but distinct questions: Should people who
exercise seek to proactively replace fluids lost, or can they rely on thirst to
guide them during and after physical activity? And when they rehydrate, do they
need all the salts, sugars, and other ingredients dumped into sports drinks, or
is water fine? The correct answers are: best to rely on thirst, and water is
fine. All that stuff about replacing electrolytes and so on you've been hearing
all these years? Never mind! The evidence doesn't support it.
Overhydration presents a far greater risk of serious complications, and even
death, than dehydration.
In a commentary accompanying the investigations in the journal, Timothy Noakes,
chair of sports science at the University of Cape Town, points out that
overhydration presents a far greater risk of serious complications, and even
death, than dehydration. Moreover, he notes, the notion that fluid and
electrolytes must be immediately replaced is based on a fundamental
misunderstanding of our past as "long distance persistence hunters" in arid
regions of Africa.
"Humans do not regulate fluid balance on a moment to moment basis," Noakes
writes. "Because of our evolutionary history, we are delayed drinkers and
correct the fluid deficits generated by exercise at, for example, the next meal,
when the electrolyte (principally sodium but also potassium) deficits are also
corrected…People optimize their hydration status by drinking according to the
dictates of thirst. Over the past 40 years humans have been misled—mainly by the
marketing departments of companies selling sports drinks—to believe that they
need to drink to stay 'ahead of thirst' to be optimally hydrated."
---Krehe Ritter
—By David Tulle
Just in time for the Summer Olympics in London, a top science journal has issued
a blistering indictment of the sports drink industry. According to the series of
reports from BMJ (formerly British Medical Journal), the makers of drinks like
Gatorade and Powerade have spent millions in research and marketing in recent
decades to persuade sports and medical professionals, not to mention the rest of
us suckers, that a primal instinct—the sensation of thirst—is an unreliable
guide for deciding when to drink. We've also been battered with the notion that
boring old water is just not good enough for preventing dehydration.
I've been as susceptible to this scam as anyone else; I knew, or thought I knew,
that if I'm thirsty after my half-hour go-round on the elliptical trainer, it
means I was underhydrated to begin with. So for years I've been trying to
remember to ignore my lack of thirst and make myself drink before working out.
Not any more.
The BMJ's package of seven papers on sports performance products packs a
collective wallop. The centerpiece is a well-reported investigation of the
long-standing financial ties between the makers of Gatorade (PepsiCo), Powerade
(Coca-Cola, an official Olympic sponsor), and Lucozaid (GlaxoSmithKline) with
sports associations, medical groups, and academic researchers. It should come as
no great surprise that the findings and recommendations that have emerged
through these affiliations have tended to include alarming warnings about
dehydration and electrolyte imbalance—warnings that conveniently promote the
financial interests of the corporate sponsors.
And who knew there was something called the Gatorade Sports Science Institute?
According to the BMJ investigation, "one of GSSI's greatest successes was to
undermine the idea that the body has a perfectly good homeostatic mechanism for
detecting and responding to dehydration—thirst." The article quotes the
institute's director as having declared, based on little reliable evidence, that
"the human thirst mechanism is an inaccurate short-term indicator of fluid
needs."
Another study in the BMJ package finds that the European Food Safety Authority,
which is authorized to assess health claims in food labels and ads, has relied
on a seriously flawed review process in approving statements related to sports
drinks. A third study reports that hundreds of performance claims made on
websites about sports products, including nutritional supplements and training
equipment as well as drinks, are largely based on questionable data, and
sometimes no apparent data at all. One overall theme emerging from the various
papers is that much of the research cited was conducted with elite and endurance
athletes, who have specific nutritional and training needs; any such findings,
however, should not be presumed to hold for the vast majority of those who
engage in physical activity.
Critics have long blasted sports drinks as being loaded with calories and
unnecessary ingredients. (Not to mention concerns about the environmental costs
of producing, shipping, and discarding all those millions of plastic bottles.)
Yet the product category represents a lucrative and growing market, with US
sales of about $1.6 billion a year, according to the BMJ. In fact, Powerade is
the official sports drink of the London Olympics, and Coca-Cola is hyping the
brand with a campaign featuring top-tier athletes.
The BMJ papers address two related but distinct questions: Should people who
exercise seek to proactively replace fluids lost, or can they rely on thirst to
guide them during and after physical activity? And when they rehydrate, do they
need all the salts, sugars, and other ingredients dumped into sports drinks, or
is water fine? The correct answers are: best to rely on thirst, and water is
fine. All that stuff about replacing electrolytes and so on you've been hearing
all these years? Never mind! The evidence doesn't support it.
Overhydration presents a far greater risk of serious complications, and even
death, than dehydration.
In a commentary accompanying the investigations in the journal, Timothy Noakes,
chair of sports science at the University of Cape Town, points out that
overhydration presents a far greater risk of serious complications, and even
death, than dehydration. Moreover, he notes, the notion that fluid and
electrolytes must be immediately replaced is based on a fundamental
misunderstanding of our past as "long distance persistence hunters" in arid
regions of Africa.
"Humans do not regulate fluid balance on a moment to moment basis," Noakes
writes. "Because of our evolutionary history, we are delayed drinkers and
correct the fluid deficits generated by exercise at, for example, the next meal,
when the electrolyte (principally sodium but also potassium) deficits are also
corrected…People optimize their hydration status by drinking according to the
dictates of thirst. Over the past 40 years humans have been misled—mainly by the
marketing departments of companies selling sports drinks—to believe that they
need to drink to stay 'ahead of thirst' to be optimally hydrated."
---Krehe Ritter