Hydrate to WIN

Hydration

By Anne Guzman

Peaks Coaching Group Nutritionist

Athletes must be fully hydrated before they train or compete because the body cannot adapt to dehydration.  Training quality will suffer if we allow ourselves to become dehydrated during training. The same goes for competition.  In fact, dehydration of as little as 2% can have a significant negative impact on performance. The sensation of thirst rarely occurs before the loss of 1.5 to 2 liters of water (approx 2% of body weight), due to plasma osmolarity.

According to the American College of Sports Medicine, thirst is NOT a good indicator of when to drink.  This is even more important with age as our thirst mechanisms decrease with age.

With many hours on the trainer and rollers indoors, it is easy to let dehydration  sneak up on you! The next thing you know, you feel weak and can’t seem to find that energy you had weeks before. Dehydration is one of the number one causes of fatigue.

In this article I will cover what you should be drinking during training rides and easy rides as well as rehydration strategies post exercise.

A simple way to check if you are hydrated is to look at your urine color. It should be pale in color. However if an athlete is taking supplements this can be unreliable as B vitamins add a yellow color. A more precise method would be to purchase an osmometer which measures urine osmolarity. Simply, an osmolarity over 900mOsmol/kg indicates that the athlete is relatively dehydrated; values of 100 to 300mOsmol/kg indicate that the athlete is well hydrated.  You can purchase one for under $300. Another test is body weight upon rising and before urinating.  A drop in body mass from day to day is likely to indicate dehydration. Ideally athletes should consume enough liquid during activity to make body weight remain fairly stable before and after exercise.  Weigh yourself before and after your training sessions. A general rule of thumb is for every pound lost; drink 500ml of fluid (2 cups).

Although there are no specific guidelines from the American or Canadian Dietetic Association regarding how much to drink (largely due to the variance in individual sweat rates), there are some guidelines in place. The American College of Sports Medicine on Fluid Intake for Exercise and the Position Stand on Exercise and Fluid Replacement (2007) for example, recommend the following:

·        Individuals should drink 6-8ml of fluid per kg of body weight about 2 hrs before exercise. Beverages with sodium or eating snacks with salt can stimulate thirst and help retain needed fluids.  During exercise, athletes should start drinking early and at regular intervals  to prevent dehydration.    Fluids should be flavored to enhance palatability and promote fluid replacement.

·        During exercise longer than 1 hour, carbohydrates should be ingested at a rate of 30-60g per hour to maintain oxidation of carbohydrates and delay fatigue. An example is drinking 600-1200ml/h of solutions containing 4%-8% carbohydrates. These carbohydrates can be sugars (glucose, sucrose) or starch (maltodextrins).

·        Inclusion of sodium (500 to 700mg/L of water) in the rehydration solution ingested during exercise longer than an hour is recommended because it may enhance palatability and promote fluid retention.

·        After exercise in situations in which people need rapid and complete recovery from excessive dehydration, 1.5L of fluid should be consumed for each kg of body weight lost.  Consuming drinks with sodium will help the attainment of rapid and complete recovery of hydration status by stimulating thirst and fluid retention.

A practical example of the above guidelines would look like this:

•        70kg male(154lbs): 2hrs Pre-training 6-8ml/kg= 420-560ml (15-19oz) Typical Bottle is 500ml.

•        Figure out your sweat loss in training: ex. 1.5L per kg lost in training/race

•        70kg male: Pre training weight: 70.38kg

•        Post training weight: 68.75

•        Drank 1x350ml bottle in training (1g/ml) adjust for this

•        So WEIGHT LOST: 1.63kg + .35kg= 1.98kg in 90min

•        Sweat Rate: 1.98/1.5=1.32L/hr

•        Recovery: 1.5L/kg weight lost

•        1.63x1.5= 2.45L in first hour or so post exercise

•        5 bike water bottles (500ml each) 1000ml=1L

The bottom line is you put ALL of that time in training and preparing for a great season. You dial in your nutrition, and you have some serious goals. Being dehydrated can significantly stress your aerobic system more than it needs to be stressed due to lowering overall blood plasma volume. This means YOUR HEART HAS TO PUMP HARDER to make the same effort because there is less oxygen available to your muscles. Just by staying focused and having a hydration plan you can optimize your fitness and be sure you stay mentally focused and be able to hit those VO2 Max numbers in a race when you need to. Hydration is vital to peak performance. It is not a side note or something to be taken lightly if you are serious about success. The only solution is to devise a strategy and stick to it.

Try setting your watch to beep every 15 minutes to remind you to take big gulps from your bottle frequently. Don’t wait until you are dehydrated to start drinking. Gastric emptying is slower once dehydrated which can lead to cramps and discomfort. The goal is to drink EARLY AND OFTEN. Big gulps increase the rate of gastric emptying so practice this in training and be prepared to use these strategies on race day.

Make hydration a goal.It could be that last missing link to your success!!!

ANNE GUZMAN- Peaks Coaching Group Nutritionist