Hydration Strategies by John Josephs, MS
Filed under: Nutrition
Hydration Strategies by John Josephs, MS
5/3/2006
FLUIDS
Water is the most common and important nutrient of the body. It accounts for approximately 60% of our total body weight.
Losing too much water from exercise without adequate hydration inhibits the body's ability for optimal performance and power output.
Dehydration of only 2% of body weight can effect performance and impair your thermoregulatory ability. (150 lbs. x 2% = 3 lbs. = 48 oz. fluid.)
Pace and power decrease by 2% for each % body weight lost to dehydration.
There is no other factor that impacts performance as quickly and as greatly as your hydration status.
Water is essential for regulating body temperature. During high intensity exercise in a hot, humid environment, an athlete may lose 2-3 liters of fluid/hour.
Water is the primary component of blood that transports fuel and oxygen to the working muscles and removes waste products (CO2 and Lactic Acid) from our system.
Less fluid means less blood volume. A decrease in blood volume increase heart rate in order to deliver oxygen and nutrients to working muscles. In addition, body temperature will increase. The combination of these factors will lead to a reduction in performance and decrease time to exhaustion.
Once we realize thirst, the initial stage of dehydration has started and replacing lost fluid at this point is difficult.
It is important to drink water steadily throughout the day when you are training. Drink 8-12 cups/day.
A general rule of thumb is to drink enough water so that you visit the bathroom every 2-4 hours and your urine is clear and odorless.
SWEAT RATE
Check your body weight (in the buff) prior to exercise.
Keep track of all fluid replacement during your exercise session.
Re-weigh yourself immediately following your workout.
Each pound of body weight loss translates into 16-20 ounces of fluid or 1000 ml. for each kg.
Determining your sweat rate is essential in shaping a successful nutritional and hydration plan for endurance training and optimizing your racing strategy.
HYDRATION STRATEGY
DO NOT drink and/or eat anything before or during the race that you have not tried previously in training.
The evening prior to the race, have a carbohydrate rich (0.5-0.7 gm/body weight) pre-race meal (low-to-moderate Glycemic Index). This meal should be consumed by 6 p.m.
Liberally salt your food to increase your sodium stores.
Hydrate well (50/50 water and carbohydrate/electrolyte drink) the evening prior to the race. You should be visiting the bathroom every 2-4 hours and your urine should be relatively clear and odorless. DO NOT OVERHYDRATE!!
PRE-RACE
Two hours prior to the race consume 16-20 oz. carbohydrate drink, preferably Gatorade or similar drink of choice. In addition, eat approximately 400 calories of easily digestible foods rich in carbohydrates (powerbars, bananas, bagels).
30 minutes prior to the start, drink 12 oz. sports drink.
Set your watch to beep every 15 minutes as a reminder to drink 6-8 oz water/gatorade or 1 cup per water stop depending on your sweat rate.
Alternate water and sports drink.
DURING
If you can tolerate gels, make sure you have two in your pocket before the race. Take the first one 45-60 min into the race, depending on your pace and predicted finish time. Make sure you wash it down with 1-2 cups water to dilute the concentrated energy source to help it be absorbed into your system. You will increase your chances of gastric distress if you fail to do so.
You will have a better time if you start hydrating early and be consistent throughout the race. DO NOT OVERHYDRATE!!
Spend a few seconds at each water stop to hydrate. Make sure you get the water down. A few seconds spent here will save you minutes later.
Position yourself for each water stop by getting over to the correct side of the road early enough.
RECOVERY
Drink 16 oz. 4:1 Carbohydrate/Protein drink within 30 min following the race to help speed recovery and aid in rebuilding damaged muscle cells. This can be a commercial drink or add 6 tablespoon sugar to 16 oz skim milk.
You have a 2-hour window to replenish your glycogen stores. The first 30 minutes are critical. Carbohydrates should have a moderate-to-high Glycemic Index. Make sure to include plenty of fruits.
Drink 1 bottle water/hour for the first 3 hours until you feel hydrated and you begin to visit the bathroom.
NOTE: I'll be the first to admit, nothing tastes better than a cold beer after working hard on a hot day. But remember, it might be counterproductive to drink beer while you're trying to rehydrate.