Ever wondered why you are always told to drink lots of fluids? Here is a question I received asking if we should really drink a gallon of water per day!

water“I just read that we should drink a gallon of water per day to maximize fat loss.  Was this a misprint? I picture myself on the restroom all day from drinking all that water. Please clarify. Thank you for your great articles!”  M.H.


Did you know that 50-70% of our total body weight is water? The brain is composed of 70 percent water, lungs are nearly 90 percent water and our blood is about 83 percent water, which helps digest our food, transport and eliminate waste and toxins, mobilize fat, and control body temperature. Think of it this way, every tissue cell, organ and system is comprised of water and functions optimally only in the presence of adequate hydration. So even fat loss will not occur at an optimal rate if you are in a dehydrated state. Plus water helps to suppress our appetite.  Water is our life force, in fact, we could only go a few days without water before our body would start to deteriorate and die. According to the American Dietetic Association’s Complete Food and Nutrition Guide, the average adult loses about two and a half quarts or about 10 cups of water daily through urine and sweat. Just cover your entire arm with a plastic bag and within a few minutes you’ll get a very visual demonstration of how much water we lose in a day. Think of the good old-fashioned sweat suits designed to make you sweat and lose weight. Yeah, you lost weight but it wasn’t fat weight, it was very valuable water weight!

To maintain your body’s fluid balance, you need to replace at least the 10 cups of water (80 ounces) everyday. This amount needs to be increased in hot weather conditions or for those who exercise who may lose up to a liter per hour during a workout. Plus, as we age, there is a general loss of water in all tissues – it’s like the plum to prune effect!  So the question is – would you prefer to be healthy, hydrated plum or a dried up, old wrinkly prune so drink your water?!

But, unfortunately most people exist in a dehydrated state. In fact, common complaints like headaches, lack of energy, feeling tired and lethargic, being prone to sickness and injury, kidney stones, constipation and achy joints and muscles have been associated with dehydration. If most people would commit to drinking 10 glasses of pure water every day they would notice a great improvement in their overall health, body composition and energy levels.

So the gallon of water or 128 ounces everyday was not a typo – some health professionals believe this is the adequate amount required if you are exercising and sweating everyday which hopefully you are!  Keep in mind though, we obtain water in our diets from drinks, either plain water or as part of other beverages and from solid foods, especially fruits and vegetables.  So we encourage clients to get at least 80 ounces of pure water and see how their body responds.  Any other additional fluids you consume in the form of juice, milk, or herbal teas will be a bonus.

Regarding your question about having to run to the bathroom throughout the day. In the beginning, your body and its tissues are not used to absorbing this higher level of fluid and so they will initially just flush it out. And yes, you will be spending a great deal of time in the restroom but it won’t last long. Eventually, your body and its tissues will start to absorb the water and your need to run to the washroom all day should decrease. Your body will soon adapt to your hydrated state. Your thirst mechanism will also become more efficient and you’ll find that the more you drink, the more thirsty you become. That’s a great sign!

Most people know they should be drinking more water but they don’t.  We’ve found it’s not in the knowing, it’s in the doing!

You’ll have to take some action steps to help you adhere to this hydration goal…here are some examples:

  • Purchase a water cooler for home and work so you always have cold, refreshing water available.
  • Be sure to drink some water every time you pass the cooler.
  • Purchase an 80 ounce water bottle from places like Fred Meyers so you can fill up your bottle in the morning and make it a goal to finish the whole thing before you go to bed.
  • Have your bottle with you wherever you go.
  • If you don’t like the big water jug idea, drink a 16 ounce glass of water first thing in the morning and then 20 minutes before each meal and snack.

You’ll easily hit 80 ounces. Many athletes use what’s called a ‘Camel-Back’, a water sac that hooks on like a back pack with a water-hose that allows you to drink easily and continuously throughout workouts. This is a great way to replenish all those extra fluids during tough workouts. During workouts, you should strive to drink 8 ounces of water every 15 minutes. During long bouts of intense endurance exercise, it’s best to use a sports drink as this will help replace sodium and electrolytes lost in sweat and reduce the chances of developing hyponatremia, which can be life-threatening.

Water and hydration is important to your overall health and hopefully this article has helped clarify some of the rationale. 

Sherri McMillan, M.Sc. has been inspiring the world to adopt a fitness lifestyle for over 25 years and has received numerous industry awards including International Personal Trainer and Fitness Presenter of the Year. She is the author of five books including “Go For Fit – the Winning Way to Fat Loss” and “Fit over Forty” and is the featured presenter in various fitness DVDs.  She is the owner of Northwest Personal Training in downtown Vancouver and can be seen running, hiking or cycling with her two children, Brianna and Jackson.  She can be reached at www.nwPersonalTraining.com or www.ShapeupwithSherri.com

Note:  As an avid Columbian reader, you can redeem a 2 week pass at her world-class training studio to help get you started.  Contact 360.574.7292 for more details.

Sherri McMillan

Sherri McMillan

Sherri McMillan, holds a master's degree in exercise physiology and has been inspiring the world to adopt a fitness lifestyle for more than 33 years. She has received numerous industry awards including 2010 CanFitPro International Presenter of the Year, 2006 IDEA Fitness Director of the Year, 1998 IDEA Personal Trainer of the Year, 1998 CanFitPro Fitness Presenter of the Year and 2005/2006 ACE Fitness Educator of the Year - Runner up. She is a fitness trainer, fitness columnist for various magazines and newspapers, author of five books and manuals including "Go For Fit - the Winning Way to Fat Loss" and "Fit over Forty" and the featured presenter in various fitness DVDs. She has presented hundreds of workshops to thousands of fitness leaders throughout Canada, Australia, Mexico, Jamaica, New Zealand, Germany, England, Spain, South America, Asia and the U.S. She is the owner of Northwest Personal Training in downtown Vancouver, the founder of WHY Racing Events & WHY Community, participates in various community fundraisers and can be found running, biking, or hiking around the community. Find more information at nwpersonaltraining.com.

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