The New Hydration Code

Forget about complicated, physician-recommended water guidelines. As a hard-training athlete, you need this “no sweat” approach to optimizing hydration.

By Dwayne N. Jackson, PhD | August 1, 2016

As Muscle & Performance reader, you’re probably more than a little acquainted with water and its value to your efforts in the gym. But water is one of those strange sports-nutrition topics that has so much information published on it that many of the crucial take-aways are lost in the literature. We know it’s essential to life and that athletes live and die by the stuff, but what if you’re just a weight-room junkie bent on getting bigger, stronger and leaner? You’ll need more water, but how much is enough?

In humans, H2O provides a dissolvable medium for transport of nutrients in blood plasma, saliva and extracellular fluid. It also makes up the liquid in sweat (needed for thermoregulation) and synovial fluid (needed for lubrication of joints). The typical adult human is made of more than 60 percent water and, because muscle mass contains up to 80 percent water, athletes should be even more waterlogged. The average daily water loss in a resting adult is about 2.6 liters; add in heat stress and heavy exercise, and water loss can climb as high as 10 to 12 liters per day. Based on this, it’s no surprise that most athletes are dehydrated, a condition that can lead to poor athletic performances and/or serious health consequences.

But there’s a lot more to know about nature’s most powerful supplement. Here, we take a dive into the deep end on the importance of water, then decode the many recommendations that exist on how to properly consume it for performance.

Water As A Diet Aid

In the quest for leanness, most athletes reach for fat-burning supplements as a first line of defense, but we suggest you seriously examine your water intake, too. Research published in Obesity illustrates that drinking 500 milliliters of water before each meal can boost weight loss when dieting. In 12 weeks, those who drank water before meals lost about 4.5 pounds, about 50 percent more than those who didn’t drink water before meals. Researchers suggested that drinking water before meals increased the feeling of fullness and decreased the total calories consumed per meal. To simplify, water actually does what some supplements only claim to do.

Water For Power Production

What you may already know about water is that it’s essential to competing athletes, but scientists are learning more about its value to iron lovers. For instance, in a study published in 2010, researchers from Missouri Western State University reported that subjects who had a controlled 3 percent body-mass loss because of sweating (without fluid replacement) performed 15 percent fewer reps when weight training to failure. In another earlier study, scientists reported that dehydration (of about 3 percent body mass) led to decreases in average and peak power in the upper body (7 and 15 percent, respectively) and lower body (19 and 18 percent, respectively) during anaerobic exercise. So if you’re one of those hardcore trainers who like to tough out dry mouth or opine that water is for the weak, it may be time to rethink things a bit.

Water As A Metabolic Booster

Researchers from Germany have shown that drinking 500 milliliters of cold water increases metabolic rate by 30 percent for about 30 minutes, which equates to a total of about 25 calories burned. In males, water-induced thermogenesis is accomplished by burning fat, whereas females burn more carbs. Based on this research, you can expect to burn about 200 extra calories per day if you drink 4 liters of cold water daily, which is infinitely easier than doing more cardio!

Thirst As An Indicator

In a study published in the Journal of the International Society of Sports Nutrition, running athletes who drank only when they felt thirsty replaced a mere 30 percent of the water they lost sweating despite having open access to water throughout their workouts. This is supported by an observational investigation conducted on elite-level rugby athletes who were studied during aerobic and resistance-training sessions. It was found that 80 percent of subjects started training in a hypohydrated state and failed to match water consumption with sweat rate. In fact, during resistance training, subjects overhydrated, and during aerobic training, subjects didn’t drink enough.

Thus, athletes should follow a predetermined regimen of fluid ingestion if they wish to maintain optimal hydration: one that accounts not only for minimum health recommendations but that also helps them to maximize performance.

The Water Debate: How Much Is Enough?

A gallon a day? Half your bodyweight in ounces per day? Six glasses a day? This is an area of scientific debate without end, it seems. According to research, daily water needs for athletes vary based on body mass, exercise intensity, environmental temperature, humidity and even kidney health.

Well, a physician will tell you to try to drink 8 cups (2 liters) of water daily and let your kidneys do the rest. On the other hand, the biggest guys in the gym will tell you to drink at least twice that. Interestingly, water ingestion is one area where bro science is closer to the target than what’s pushed in popular medicine.

If you work and/or train in a temperature-controlled environment, drink 2 liters of water per day as a minimum baseline, then add in 500 milliliters before each main meal and (on training days) 500 milliliters 20 to 30 minutes before training. This approach will bring your daily water consumption to 4 liters, timed so that you can take advantage of water’s training and dietary benefits.

If you work and/or train in a hot environment, then you’ll need to increase your water consumption to match sweat rate. You likely won’t have a means to measure your sweat rate or specific gravity of your urine, as performance coaches do, so we recommend keeping an eye on your urine color and smell: If it’s clear and odorless, then you’re good to go. If it’s cloudy and rank, then it’s time to reach for your water bottle.

Too Much Of A Good Thing

It should be noted that overhydration can lead to deficits in performance comparable to underhydration. Moreover, consuming too much water in a short period can lead to potentially fatal water intoxication, also known as water poisoning or dilutional hyponatremia. The key to avoiding overhydration is to sip water throughout the day and pay attention to urine color and smell. Do not chug liters of water in a single sitting.



About the Author

Dwayne N. Jackson, PhD

Dwayne N. Jackson, PhD, is a professor and scientist in medical biophysics at one of Canada’s top medical schools, the University of Western Ontario. He has over 12 years of university education in physiology and has attended the University of Ottawa, the University of Western Ontario and the Yale School of Medicine. He also has over 20 years of competitive and recreational bodybuilding experience and is an expert in the areas of performance nutrition and supplementation.