Sunday, November 13, 2011

Sunday, November 13, 2011

Congratulations John B., for completing Saturday’s SunTrust Richmond Marathon in 3:05.13!

This weekend, Christy P. competes in the Mid-Atlantic Hopper Challenge (Facebook page). Join us in Maryland to support her as she defends her title, and good luck, CP!

Part Four: Hydration and Performance or Do Drink the Water

Your body is about 72 percent water—it’s everywhere—in blood vessels, interstitial tissues, and lymph and cerebral spinal fluids, to name a few. Its polarity and salt content create the electrical charge that powers your neurological system. Water is also an essential part of the body’s metabolic processes, such as the metabolism of fat into usable energy in the liver, or the production of adenosine triphosphate (ATP), a compound used as chemical energy in the body. Because metabolic processes in your body continually deplete its water stores, you must replenish them via fluid consumption and from the water content of food. If water is not replaced at a rate equal to its loss, dehydration results, and consequently, these tissues and chemical processes—you—suffer.

The work we do is hard (enough), and that’s why it is effective. Yet, many walk into the workout every day without proper preparation—in a dehydrated state. In all athletics and exercise, dehydration induces premature fatigue, as it deteriorates cardiovascular and thermoregulatory processes. Studies have demonstrated that dehydration levels of even two percent are enough to impair performance. Without proper fluid levels, blood chemistry changes—blood becomes more viscous, and its osmolality (concentration of salt ions) changes as its total volume decreases. This, in turn, decreases cardiac output, the total volume of blood pumped through your heart and to fuel-hungry muscles during a period of training. Additionally, your body produces heat as a byproduct of the chemical reactions that occur when work is performed by muscle tissue. Since the evaporation of sweat is your body’s primary method for heat regulation, a decrease in available water leads to a decrease in sweating, and therefore reduces your body’s capacity for cooling. Without a pathway for heat release, performance becomes disadvantaged. Finally, because water is the most abundant substance found in muscle, nerve, bone and connective tissue, dehydration results in heightened stiffness and soreness.

We can do better than to train un-supple and dried-out. While it may be difficult to consistently sleep enough, or fuel properly, it is certainly reasonable to drink enough water—all it takes is a few Nalgene bottles or the equivalent throughout the day (yes, your old friend: planning). But, exactly how much? Baseline daily water consumption is dependent on body size, climate and physical activity, among other variables. A helpful guideline, among many, is that an individual should consume one-half of his or her body weight in ounces each day, although this only takes into account beverages that do not contain caffeine or alcohol, since both have a diuretic effect.

Additionally, both water and electrolytes lost during physical activity in the form of perspiration must be completely replenished to maintain hydration levels. Electrolytes, when dissolved in water, become ions that have the capacity to carry electrical current through your nervous system, allowing your muscles to fire—work. For every 16 ounces of water lost during exercise, about 220mg of sodium, 63 mg of potassium, 8 mg of magnesium, and 16 mg of calcium are also lost. Luckily, these can be easily replenished by consuming slightly salty water, such as coconut water or chicken broth, post-workout. Salting foods with sea salt, rather than ultra-refined table salt, or consuming pickled foods will also help restore electrolyte balance, and saltsticks or electrolyte replacement powders can also be employed. Because a Paleo diet often has significantly less salt than a traditional Western diet, it may be necessary to further increase salt intake in order to restore your electrolyte balance. Without electrolytes, a large percentage of ingested water will simply head straight for your kidneys to be excreted as urine, never reaching its intended targets.

Hydration status can be tested most easily by a few home field tests. To measure water loss within a training session, weigh yourself before and after a workout (obviously, without the sweaty clothes). The water lost in pounds must be replaced before the next workout, in addition to achieving the baseline. It is also helpful to monitor water loss overnight via a weigh-in before and after sleeping, and to strive to replace this water as soon as possible in the morning. Finally, another method to create awareness about your personal hydration level is to examine your urine—its color, odor and volume. Urine should have a pale yellow color (think lemonade; there, we said it) and should be relatively odorless. It should not be darker, especially after a workout, or have a strong odor, or be of small volume.

The more challenging the workout, or the hotter the environment, the more water you must consume. The American College of Sports Medicine, for example, recommends that athletes stave off dehydration by ingesting between 500 mL and 1000 mL of water prior to exercise, depending on the expected intensity of the training. They also state that an athlete training in a hot and humid environment can lose upwards of 2500 mL of water in an hour. That’s over five pounds which must then be replaced—once again, in addition to daily baseline water requirements.

The bottom line: do not wait until five minutes before class to get your hydration on—the hay is in the barn, so-to-speak. Instead, begin the process the day and night before. Then, be sure to re-hydrate with water and salt after the session is over. Just as it is important to fuel properly, it is necessary to hydrate well for performance, and nutrition and hydration must be viewed as two distinct entities. Take an honest look at your hydration strategy. Be aware of your water intake, and your recovery and performance in the gym will improve—your results will improve.

If you would like to do more reading on this topic, please review these studies and links:

“Dehydration, Hyperthemia, and Athletes: Science and Practice”

“Exercise and Fluid Replacement”

“Sweat Rate and Sodium Loss During Work in the Heat”

“Measuring Hydration Status in Athletes” (NSCA PTJ 9-5)

“Does Caffeine Promote Dehydration?” (NSCA PTJ 9-6)

“What About Pre-Race and Race Nutrition and Hydration?”

Rest today.

–Melody and John