Anyone besides me only do your weigh-ins after you workout?  I wait because I know after 60 minutes of burning calories and sweating my ass off, I can expect to be a pound or two lighter than when I started.  But looking into this hydration issue got me wondering… maybe I should be a little less encouraged and a little more concerned about my superficial post-WOD weight loss.

In a typical workout, we can sweat out about 2% of our body weight in water.  Even though our bodies are more than 60% water, it takes a surprisingly slim margin of loss for our athletic performance to be negatively affected.  Below is a chart of symptoms you might experience as dehydration sets in.

1%       Marked reduction in VO2 max
2%      Thirsty, loss of endurance capacity
3%      Dry mouth, performance impaired
4%      Increased effort for exercise, discomfort
5%      Difficulty concentrating, increased pulse
11%      Heat Exhaustion, stroke, delirium, or death

Your VO2 max is the maximum capacity of your body to use oxygen during exercise.  At a “normal” range of 2% of dehydration, your body is already experiencing symptoms that hinder athletic performance.  If you’re dehydrated before you begin working out, expect fatigue and discomfort to strike even sooner.  How much better might we perform if we kept this dehydration to a minimum?

We can’t stop ourselves from sweating – and we don’t want to; it’s how our bodies safely regulate our temperature as exercise increases our core temps.  So what can we do to avoid the resulting dehydration?  The best answer is the obvious: drink more water.  Before you WOD, while you WOD, after you WOD.  It doesn’t get much simpler than that.

Here are a couple other things to consider: 

Electrolytes.  Although a glass of water will replenish the fluids lost in a workout, sweating releases vital minerals like potassium, sodium and calcium.  Be sure that your recovery shakes and post-WOD foods support not only your muscle recovery, but rehydration through the supply of electrolytes.  I usually have a banana with my protein shake to ensure I get a good dose of potassium.

Sources.  Drinking plain old boring water works wonders (or sparkling water for you fancy pants).  But consider other sources, such as sports drinks, fitness water, and coconut water for variation.  Depending on your fitness and weight loss goals, you can find a tastier source than tap water to provide your desired electrolytes and glucose (for energy).

Caffeine and Alcohol.  As diuretics, consuming either source will increase your fluid output and cause greater dehydration than avoiding them entirely.  The caffeine is tricky for me - I’m usually on my 3rd or 4th cup of coffee by the time I get to the gym in the morning!  But I’m going to start cutting back (as my sanity allows), and supplement with a vitamin B tablet pre-workout.  The vitamin B should give me the extra energy I derive from the caffeine, without the negative effects on hydration.

Glasses, not Gallons.  Aim to drink your eight 8-oz glasses evenly throughout the day.  We are not camels.  Our bodies cannot store excess water.  Unless you’re prepping for a 90-minute session of Bikram yoga, downing a half-gallon of water is probably unnecessary.

Experiment.  Not sure how well you’re doing?  Weigh yourself before and after a really gritty workout.  Vary up your water intake week to week and see what differences it makes in not only your pre- and post-WOD weights, but how you feel.  My guess is you’ll see noticeable improvements in performance and recovery.

Want to hear it from an expert? 

"I drink a lot of coconut water. It balances out all the other toxic stuff I put into my body."  - Rihanna