Wet Your Whistle
The human body consists mainly of water...approximately 70%, depending on your source of information...much like the earth. The exact amount depends on your age, gender and your muscle to fat ratio. Muscle tissue has more water than fat tissue and therefore a young, active body contains more water than an older, sedentary one.
Although it wouldn't necessarily be a fun experience you could survive weeks without food...but merely days without water. Maybe even less in a hot environment that would cause you to sweat profusely and dehydrate even quicker.
The term electrolyte is used to describe sodium, potassium, and chlorine, the minerals that help the body maintain fluid balance. Hence, the advertisement campaign put on by sports drinks manufacturers. In reality, you only need a sport drink to replenish those minerals when engaging in over 1h of hard exercise on a hot day...even then the sodium levels in some of these drinks are so high that you would be best of drinking water only and having a banana for potassium replenishment once finished with your training or event.
Under normal circumstances, it's hard for healthy people on normal diets to drink too much water to where there would be a safety concern. Drink more water than you need, urinate more abundantly, and your water level readjusts. But if you do not get enough water, your body lets you know pretty quickly. The unpleasant dryness in your mouth caused by the loss of water from cells is your first sign. If you don't pay attention to these signs, you begin to dehydrate, or dry out. Your body begins to horde the fluid it can and urination is reduced. At this point, if you do not drink it can be fatal.
At this point we are all aware that we should drink about 8 8oz. glasses of water on a general basis thoughout the day. So, how much water do we need on the days we train or participate in a competitive event?
Based on available evidence, the American College of Sports Medicine makes the following general recommendations on the amount and composition of fluid that should be ingested in preparation for, during, and after exercise or athletic competition:
- Approximately 17 ounces of fluid should be consumed about 2 h before exercise
- During exercise, athletes should start drinking early and at regular intervals in an attempt to consume fluids at a rate sufficient to replace all the water lost through sweating
- Addition of proper amounts of carbohydrates and/or electrolytes to a fluid replacement solution is recommended for exercise events of duration greater than 1 h since it does not significantly impair water delivery to the body and may enhance performance. During exercise lasting less than 1 h, there is little evidence of physiological or physical performance differences between consuming a carbohydrate-electrolyte drink and plain water.
- Replenish fluids post-event.
ACSM's Position Stand, "Exercise and Fluid Replacement," is the fourth official statement addressing fluid replacement guidelines and recommendations for fluid ingestion and the prevention of heat injury during exercise. See it online at www.acsm-msse.org .