Preworkout hydration

by Mike

Dehydration is one of the more dangerous parts of training (or any exercise, really), yet drinking water is often looked down on in many gyms - a holdout of the old-school toughguy days. 

The Grappler's Guide to Sport Nutrition tells us that dehydration is be a serious bogeyman, and 

can lead to increases in perceived exertion and central fatigue, a reduction in plasma volume (blood volume), decreases in sweat rate and cooling, decrease in mental performance, a decrease in fine motor skills and precision, and a decrease in endurance and work capacity.

Obviously, avoiding dehydration is something that is both necessary and easier said than done (and hydration during a workout is another subject entirely), but one of the best ways to cut down on the effects of dehydration is to make sure you're properly hydrated before going into the workout. Now, how should one do that?

The American College of Sports Medicine suggests:

To avoid or delay the detrimental effects of dehydration during exercise, individuals appear to benefit from fluid ingested prior to competition. For instance, water ingested 60 min before exercise will enhance thermoregulation and lower heart rate during exercise (34,56). However, urine volume will increase as much as 4 times that measured without preexercise fluid intake. Pragmatically, ingestion of 400-600 ml of water 2 h before exercise should allow renal mechanisms sufficient time to regulate total body fluid volume and osmolality at optimal preexercise levels and help delay or avoid detrimental effects of dehydration during exercise.

A-wuh?

Basically: drink 12-20 oz. two hours before a workout to ensure proper hydration (and still have enough time to take a leak and get rid of any excess).

The knuckleheads then ask: How do I know if I should drink 12 or 20? Well, that depends: how much do you sweat? How hard are you working out? Do you get terribly thirsty during/after the workouts? Do you need to run to the bathroom in the middle of the workout for fear of wetting yourself in the middle of a round? Aka, experiment. 

Even if you think you're properly hydrated before a workout, be sure to follow the above guidelines to make sure that you're "topped off" and you'll have one less thing to worry about during training.

CC-licensed flickr photo by lanier67.