Hydration

Hydration:  Why We Should Care

As runners, we all hear about hydration.  However many of us just drink when we feel thirsty and really don’t think much further about hydration.  We hope this web posting helps you understand what is going on in your body, and what you should be doing to keep hydrated—and keep your body operating at it’s best.

Why Water is Important

Water carries out a variety of functions within our body, and is critical to regulating our body temperature, carrying nutrients to our cells, flushing toxins from our body and transporting oxygen throughout our body.

Dehydration is the condition where there is not enough water to carry on normal functions.   Dehydration occurs when we lose more water than we take in.  Water makes up about 60% of our body, however even a relatively small loss of water can lead to a loss of athletic performance.

The effects from dehydration (listed below) can be pretty scary…and often people don’t realize that they can get relief just by sitting down in the shade and drinking some water.

Stages of Dehydration

(Source: Rehrer, N. “The maintenance of fluid balance during exercise.” International Journal of Sports Medicine (1994)

How Much Water Should I Drink?

A simple question, without an easy answer.

Different people require different amounts of water, and athletes need even more.  It was reported that Alberto Salazar sweated out more than one gallon per hour during the 1984 Olympic Marathon in Los Angeles!

The literature on fluid replacement varies.  USA Track & Field recommends a gallon per day (but does not adjust for the fact that different body sizes and types have different requirements).  The Institute of Medicine says that the average male should consume about 3L per day of beverages, and a woman about 2.2L.  This is for a non-athlete, however, so you should probably drink more.

Endurance athletes also need additional liquid, particularly while training in hot weather.

One other factor to consider is that while exercising, blood is redirected from the stomach to other muscles and organs, so the athlete’s ability to absorb water decreases.  So it is very beneficial to be well hydrated before starting training.

So, what should an athlete do?

1. Prepare.  Keep yourself hydrated at all times.  Overnight, you become a little dehydrated, so start the day with a glass of water as soon as you wake up in the morning (a great tip from Monta Vista Running’s friend Erica McLain!).  Continue to drink small amounts of water throughout the day.  Have a goal of consuming 3 to 4L of water on a regular basis every day.  A good way to monitor this is to get a 1L water bottle, fill it up in the morning, and finish the bottle by lunch.  Refill the bottle and drink about half in the rest of the time before your workout, and finish the bottle immediately after your workout, and refill the bottle again.  Finish that bottle before you go to bed. Together with other fluids you might drink at meals, the glass of water you have when you wake up in the morning, you are probably going to be OK.
2. Prevent.  During training, try to drink 4-6 oz of water every 20 minutes or so.  Drink before you feel thirsty!  Distance runners are not always in locations that are convenient to water sources so think about purchasing and carrying a small hand-held water bottle (such as an Amphipod) on long runs on the trails.
3. Monitor.  If you are rarely thirsty, and you are producing about 1.5L of clear or pale yellow urine each day, you are probably drinking enough fluids (source:  Mayo Clinic website).

If you are very concerned about your fluid intake, see your doctor or a registered dietitian.  These are professional experts and will have more information on your needs than your coaches.  He or she can help you determine how much liquid you need.

Electrolytes (and are sports drinks important?)

When an athlete sweats, the athlete loses more than just water.  Electrolytes (sodium, potassium, magnesium, and calcium) are also lost with each drop of sweat.  Electrolytes are important because your body’s cells (especially cells in your heart, muscles and nerves) use electrolytes to maintain electrical voltages across and between cells.  These electrical impulse control vision, movement, thinking, and many other activities that you take for granted.  Muscle cramps more likely if you have less electrolytes than you need.  Electrolytes also help digest and produce proteins and are a major component of muscle tissue.

So, the electrolytes you lose through sweat need to be replaced.

There are a few simple approaches to replacing electrolytes in your body.

• You lose more sodium than any other electrolyte (13-54mg per 28g (1oz) of sweat, compared to only 0.7 to 9mg per 28g for magnesium, calcium and potassium).  Simply adding a little more salt to your diet can replace the sodium lost during exercise.  Tomato or chicken soup has salt/sodium and also helps replace lost fluids, so soup can be a good post-run recovery snack.  Pretzels are also a good recovery snack, providing salt and some carbohydrates (potato chips are NOT a good snack!).
• Look for foods that will help replace the electrolytes you need.  One banana has the potassium contained in a gallon of Gatorade, so a banana is a better choice.  A glass of milk, or some cottage cheese, can replace lost calcium (as well as lost fluids); milk or chocolate milk is a great natural recovery drink.  Dark, leafy green vegetables, as well as bananas, dried apricots, avocados, almonds, legumes and soy products, can provide magnesium.
• Sports drinks can be useful—but only as a supplement to eating right.  If you are drinking sports drinks (a) be careful about using high-calorie drinks, the sugar can hit your system hard and lead to spikes and crashes in energy; and (b) make sure that the drink has the magnesium, calcium and potassium you need.   There are lots of sports drinks out there and you can find one that you like.  Personally, I find that Nuun tablets seem to work for me; Nuun has some sodium, magnesium, potassium, and calcium, it tastes good and I like the fact that it comes in tablets I can keep in a backpack and add to tap or bottled water anytime or place.  It’s a little pricey but not too bad compared to Gatorade.  However, I also start my day with a banana, a handful of almonds, and a glass of water, I often have a glass of milk after a workout, and I eat lots of salads and green leafy vegetables so I get electrolytes in more natural ways too.  If you like Gatorade, that’s OK and we are glad you are drinking something, but it’s important to be eating right and getting electrolytes in a natural way, too.  Frankly, we don’t need to spend much money on sports drinks if we are eating and drinking right, but sports drinks can help us fight dehydration.

Some Dietary Sources of Electrolytes

Conclusion and Final Thoughts

We hope that this write up (and the presentation to the cross country team on August 24) will help you understand hydration a little more and think about your fluid intake a little more carefully.   If you are ever concerned that yourself or a teammate may be dehydrated during a workout or competition, make sure you contact a coach or trainer immediately.

This paper is not intended to be fully systematic or complete.  If there are any concerns about any of the suggestions or recommendations in this paper, or if you have concerns about your diet or hydration and you would like a professional opinion on your situation, please consult a physician or dietician for a professional opinion.

Dehydration is serious!  However with attention and care, we can avoid becoming dehydrated, train and compete safely, and also perform at our best.

 Take the Test

Do you think you learned something about hydration?  Find out!  Take this quick quiz at:

http://www.classmarker.com/online-test/start/?quiz=afg4e51979ae90a0

The quiz will be available from August 24 to September 1.