Sports Nutrition

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Determining sweat loss

Monday, November 12th, 2012

  Do you know how much fluid you should drink while exercising?

Appropriate hydration during exercise is important.  For years, the emphasis was on drinking enough fluid during training to prevent problems such as heatstroke. Recently, more attention has been given to over-hydration and now people come to me with fears of water intoxication or dilutional hyponatremia.  There is a lot of confusion about the appropriate amount of water to consume during exercise but the following
technique can help you develop a personalized hydration plan.

First, jump onto a digital scale immediately before an hour long bout of exercise.  At the end of the workout, take your weight again, using the same scale. Also record the amount of fluid consumed.  Both weights should be the same if your hydration was appropriate.  Weight gain indicates that too much fluid was consumed. Weight loss indicates dehydration and the need to increase your fluid intake during exercise.  Each pound of
weight loss is equivalent to 16 ounces of sweat that was not replaced. To increase the accuracy of your hydration plan, repeat this test in various weather conditions and through a range of temperatures.  This is especially important if you train outside.

Example:  A runner who weighed 180 pounds before an hour long run weighed 179 pounds after the run.  During the run, he drank 10 ounces of water.  He had a total sweat loss of 26 ounces and should drink an additional 16 ounces of fluid the next time he trains.

Is there any aid in Gatorade or Powerade?

Thursday, August 9th, 2012

  Often, I am asked what brand of sports drinks, gels, energy bars, or protein bars is the best.   Regardless of the type of food product, I always answer that the best brand is the one that tastes the best to them and that settles the best in your GI tract.

Engineered sport products are more about convenience than necessity. Sports foods and fluids are not sources of “magic ingredients”, are not better digested than standard fuels, are not likely to enhance performance, are not necessary BUT they are a booming business in the food and sports industry.   In fact, the number of sports drink products is expected to grow by 33% worldwide in 2012. What more could we “need” from a beverage??

Experiment during training to see if these products are worth the money or if you would do just as well with real “sport foods”such as chocolate milk, bananas, pretzels, broth, flat soda, etc. Often, real foods taste a lot better and leave more money in your wallet!

Beet up on your competition?

Tuesday, June 26th, 2012

 At the Tour de France in 2011, beetroot juice made its large scale debut as a potential legal performance enhancing supplement.  Initial studies
do suggest that beetroot, also know as the garden beet, may improve performance by delaying the time it takes to fatigue. Should you be
drinking it?

In 2010, researchers at Peninsula Medical School in the United Kingdom found that cycling performance improved by 16% when cyclist consumed a
glass of beet juice a day.  Similar results have been found in other studies, such as one at St. Louis University in which researchers found
that eating a little less than a cup of baked beets an hour before running improved speed slightly.

The mechanism behind this potential benefit may lie in the high nitrate content of the beet.  Nitrate widens blood vessels in the body, allowing
blood to flow more easily.  It is suggested that eating nitrate before exercising may reduce the VO2 max (amount of oxygen needed) and
increase muscle efficiency.  Further studies are now being conducted to see if beetroot juice could be useful beyond athletics, such as in the
treatment of high blood pressure.

At this time, it is best to use caution pending more studies.  All of the studies conducted thus far have included only a small number of
subjects.  Furthermore, doses used in these studies provided almost twice as much nitrate as deemed the acceptable daily level of nitrate by
the World Health Organization.

Cuckoo for coconuts?

Tuesday, March 6th, 2012

     Coconut water, the clear juice found inside young coconuts, is one of the latest American health crazes. Should everyone be drinking it?

Coconut water does not contain any fat or cholesterol and is low in calorie – all three of which land coconut water smack dab in three big nutrition trends right now.  This explains some of the hype around coconut water. Coconut water does contain water, a little carbohydrate, a little sodium, and a lot of potassium. It is largely this high potassium content that is responsible for the rest of the hype.

Research shows that adequate potassium in the diet is essential for health.  However, potassium is also found in fruits and vegetables, which most people aren’t getting enough of.  Relying solely on coconut water as a source of potassium is not recommended because it will not provide the additional nutrients that can be obtained through fruits and vegetables.

Is this potassium content a huge benefit after exercise, as claimed by coconut water manufacturers? First, most people don’t exercise heavily enough to need an electrolyte replacement drink and would be fine with plain
water.  For those exercising strenuously, electrolytes are lost through sweat and replacing these would be beneficial.  However, the ratio of sodium to potassium in coconut water is not ideal for replenishing stores.  Coconut water has a lot of potassium and a little sodium and this is the opposite of what is needed after a hard workout.

On a side note, coconut oil, long recommended against due to its saturated fat content, may not be unhealthy as originally believed. The latest evidence shows that in the short-term, virgin coconut oil doesn’t have
the same harmful effects on cholesterol levels as other saturated fats.  It doesn’t seem to improve cholesterol levels as well as other plant oils, such as olive and canola oils, but it is no longer thought necessary to avoid coconut oil altogether.

Bottom line: Coconut water is not a miracle cure (because there isn’t one) nor should it be used as a water replacement; however, if the 3+ bucks a pop price tag doesn’t faze you, coconut water may be a refreshing
and nutritious beverage choice for you. If you are a heavy sweater and want to replenish your electrolytes after a heavy workout, grab a handful of pretzels and a bottle of water.  Stay tuned for
more research about coconut oil.  As always, moderation and mindful eating are always successful strategies for a healthy diet.

 

“4”

Wednesday, May 11th, 2011

Given the arrival of spring sports, this quick bite focuses on “4”, as in the number of hours to eat before exercise to fuel up the body and enhance performance.    This is only a general rule and just as the muscles need to be trained, so does the athlete need to train their GI tract before the main event.

Carbohydrates are an important fuel, providing energy to the muscles and the brain.  A carbohydrate-based pre-event meal has been shown to improve performance in athletes.  Keep in mind, however, that the majority of people eat carbohydrates in excess and do not need to “carb load” as much as they might think, particularly for the more casual and less active athletes.  Remember, carbohydrates are found in breads, rices, pastas, fruits and fruit juices, starchy vegetables, dairy foods, sugar, honey, and other sweeteners.  So, keep the T-baller to a regularly balanced meal but consider a meal with 2 cups of pasta, a double serving, and a cup of milk for the competitive soccer player the day before game day.

Early morning games or events pose additional consideration for the athlete.  After an overnight fast, the blood sugar and energy levels are low.  If it is possible to wake up and eat 4 hours beforehand,
do so.  Choose carbohydrate-based foods, such as bagels, fruit, or fruit juice, or a yogurt.  Adding a little fat and protein, such as light cream cheese or peanut butter may help maintain energy levels
longer.   If there is not time to eat before the event, plan ahead with a slightly bigger low-fat dinner.  Add a bedtime snack as well to try and lessen the drop in energy level in the morning.

Some athletes may also benefit from an additional snack just before the exercise or even during the exercise.  In events of longer duration (>1 hour) and as long as the intensity is moderate (the pace can be maintained for at least 30 minutes), the body can digest fuel during exercise.  In these instances, a light carbohydrate snack, such as medium banana or 8 oz low fat milk, may be beneficial.

If the pace is more intense, such as in sprinting, the body must direct blood flow to working muscles instead of the stomach.  Eating during these types of events may cause discomfort or nausea.  Therefore, it is best to stick to the 4 hour beforehand fuel-up and allow adequate time for the stomach to empty.

Here’s the bottom line: Fueling up with a carbohydrate-based meal 4 hours prior to exercise has been shown to improve performance.  An additional carbohydrate-based snack just before the event and possible during the event may also be beneficial.  The level of intensity and duration of the event play a large role in how much, when, and what fuels to consume.  For all athletes, the key is to experiment with different foods and different timing during training to find the best eating plan for the main event.

Hydrating via the pee test

Thursday, May 20th, 2010

Temperatures are rising and spring sports are in full swing.  Now is a great time to remind kids about staying hydrated.  The average child needs 48 ounces of water daily (six 8 oz cups.)  Add to that an additional 8 ounces of water for each half hour of strenuous activity.  Is your child drinking enough?   A great way to teach children how to check their hydration status is by telling them about the pee test.  Having near colorless and odorless urine and having to urinate frequently are signs of good hydration.  Thus, your child can tell that its time to drink more if they don’t have to urinate often or have dark yellow colored or strong smelling urine.

Be sure to help you child choose their drinks wisely.  Good old water is all that is need for day to day hydration.  Water is also adequate for athletic activities less than 1 hour in length. There are a bevy of beverages available these days – fruit drinks, sports drinks, enhanced “waters” – but these for the most part are unnecessary and provide empty calories.  Sports drinks and diluted 100% fruit juice can be useful for strenuous activities greater than an hour.  When exercising continuously for this length of time, the sugar and electrolytes in these drinks provide additional fuel to muscles.  After strenuous exercise, encourage you child to drink a glass of milk.  The protein and carbohydrate in milk will help with recovery.