Good morning.  My sister-in-law sent me the following study about the use of skimmed milk to prevent dehydration after a workout. 

Enjoy!

Chris Heupel

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Study plays up skimmed milk sports hydration boost

By Neil Merrett

7/30/2008- Skimmed milk may become an unlikely new secret weapon within
an athlete's kit bag, with new research linking the product to a
beneficial effect on preventing dehydration after a workout.

The Milk Development Council-funded study, appearing in the European
Journal of Applied Physiology, backs similar research suggesting that
skimmed milk is more effective at post exercise hydration then a
commercially available carbohydrate-electrolyte drink.

Researchers at Loughborough University's School of Sport and Exercise
Sciences, said that in trials of seven male subjects, consuming milk
after exercising was found to ensure improved fluid balance to the
energy drink.

Following post-exercise testing, the study found that subjects who had
consumed skimmed milk had a positive fluid balance three hours after
exercising, while those consuming electrolyte-fortified products were
more negatively affected.

The team, led by Phillip Watson, added that while milk had been found in
the study to improve fluid retention over the commercially available
carbohydrate-electrolyte drink, Powerade, there were no differences in
terms of the exercise capacity of respondents. 

However, citing previous research, the study stressed that the link
between the availability of carbohydrates and fatigue after prolonged
exercise has been widely acknowledged.

"The progressive depletion of the muscle's limited supply of glycogen
and reductions in circulating blood glucose concentrations have both
been linked to a loss of performance in endurance-type events," said the
researchers.

As part of the study's conclusions, replacing electrolyte loss was
highlighted an essential factor in restoring water balance in the human
body, to which it was claimed that milk is well suited.

"Compared to many other fluid replacement options available to the
sports performer, milk contains relatively large quantities of
electrolytes," stated the researchers.

Sports drink multi-tasking

While agreeing that being fully hydrated before, during and after
exercise was essential to ensuring a strong performance, David Rogerson,
a sports nutritionist at Sheffield Hallam University, said other factors
often needed to be considered in athlete performance.

Commenting independently on the research, Rogerson added that there were
many different types of sports drinks on the market for various
purposes, from products to be consumed before training or competition,
to formulations designed for use during or after exercise.

He claimed that a number of factors needed to be considered in terms of
providing sports benefits.

"[These benefits include] the availability of energy for immediate
performance and energy replenishment post exercise, and proteins and
amino acids for muscle repair and nerve impulse conduction," Rogerson
told DairyReporter.com.

"Sports drinks will often contain additional vitamins, minerals,
antioxidants that will assist energy production, help prevent or limit
oxidative damage from performance and facilitate the recovery processes
as well as assist hydration. 

While sport drinks makers were continuing to research product innovation
in a bid to produce more sophisticated energy products, Rogerson said
that water should nonetheless remain a starting point in maintaining
hydration.

Methodology

In performing the Loughborough testing, the researchers took seven male
volunteers with an average age of 23, excluding any lactose intolerant
subjects, to test there reaction to hydration under fixed-temperature
conditions.

Before exercising, respondents were required to detail dietary intake
and physical activity during the 48 hours before the trials, while no
alcohol or strenuous exercise was allowed during the 24 hours before
testing. 

An overnight fast was also required by each subject during the evening
before trials took place to ensure better metabolic balance between each
subject. Each respondent was then asked to ingest 500ml of plan water
90 minutes before arriving at the laboratory. 

Urine and blood tests were then taken along with the application of an
absorbent patch on their backs to measure sweat upon arrival.

Each subject was then put into a climatic chamber kept at a temperature
of about 35 degrees Celsius and humidity of between 60 to 70 per cent
where they were measured for their nude body mass to the nearest 10
grams, the researchers said.

Subject were then required to undergo 10-minute long cycling sessions
with five minute breaks in between for towel drying and nude body mass
testing.

"Sweat losses were determined for each period of exercise through
changes in body mass, and this pattern of activity and rest continued
until the subject had lost approximately 1.8 per cent of the initial
body mass," stated the researchers.

The sweat patch was then removed after the subjects were found to have
lost one per cent of body mass. 

Half an hour after testing had finished, respondents were then given
either a skimmed milk or commercially available carbohydrate-electrolyte
drink measuring 150 per cent of the body mass lost during exercise. The
drinks were supplied in four equal helpings every 15 minutes, according
to the researchers.

Once the practice was complete, subjects were then asked to rest for an
additional three hours without consuming any other food or drink
samples, before being asked to empty their bladders as much as possible.

The difference in new fluid balance between pre-exercise to afterwards
was measured through sweat lost, beverage ingested and urine produced,
according to the researchers.

Source: European Journal of Applied Physiology
Published online, DOI 10.1007/s00421-008-0809-4
"A comparison of the effects of milk and a carbohydrate-electrolyte
drink on the restoration of fluid balance and exercise capacity
in a hot, humid environment."
Authors: Phillip Watson, Thomas Love, Ronald J. Maughan, Susan M.
Shirreffs

Douglas S. Kalman PhD, RD, CCRC, FACN

Miami Research Associates

Director, Nutrition & Applied Clinical Research

6141 Sunset Drive #301

Miami, FL. 33143

305-666-2368

305-595-9239 (fax)

www.miamiresearch.com <http://www.miamiresearch.com>