January 12, 2023 4 min read

For best results during racing and training, you should have a hydration strategy. The key will be to find what your body needs, what works with your training, your schedule and your tastes.

 Here are some things you've probably heard about water:

  1. By the time you feel thirsty, you're already dehydrated.
  2. Dehydration results in a decline in sports performance.
  3. The human body is mostly water.
  4. You should be drinking 8 glasses of water every day.

So, three of those are absolutely true but the last one is just a guideline. As with anything regarding people and You might need more, you might need less. Your needs will vary depending on conditions and activity levels. As with anything to do with performance, digestion and nutrient absorption, there are too many variables for any single metric like "8 glasses of water every day" to be accurate and universally applicable. With something so simple as water, you can still get it quite wrong. 

But just to emphasize how important hydration is, it is worth noting dehydration of just 2% will impair performance, to some measures, up to 20%. That's a lot of performance to give up when it is as simple as drinking more to keep going strong.


How To We Get It Right?

Thankfully, we're smart people. Our bodies come pre-loaded with a bunch of hormones and other mechanisms that give us signals. Secondly, we have the ability of cognitive reasoning to do things like observe, to take in information, to remember and recall, to compare and contrast and to take action. 

For example:

  • Your body will send you signals when it needs water:  you feel thirsty.
  • You've done workouts before and you know you sweat.  
  • You also know you sweat more in certain conditions than others.
  • You also know if you sweat more or less that other people.
  • A longer workout requires more water than a shorter one.  

(And sweating less than "normal" isn't a good think, by the way but that's a whole other issue and not one being covered here.)


You Are Not A Camel 

Among other things that happen when you train, your your sweat rate kicks up as your body tries to maintain core body temperature. As well, your heart rate increases in order to deliver more oxygen and nutrients to your working body.  However, when you train, the rate of water loss through sweat and expiration will most often outpace your sensation of thirst and other dehydration indicators.  And here's the kicker:  since we aren't camels, we don't have anyway to store water. What we lose, we need to replace. When we train, we lose more so we need to drink more.  You are an athlete and you have a lot of hours of training ahead of you so make a hydration plan to support your training.  


Replace Sweat Loss But How Much Is That?

Simply put, you need to drink enough to replace your losses. One simple and common strategy is to weigh yourself before and after a workout to see how much weight you might have lost.  Factoring your fluid inputs and outputs and your weight change will give you a pretty good estimate of your sweat loss.  A litre of water weighs one kilogram or 2.2 pounds.  One pound of water is a volume of approximately 16 ounces or 2 cups.  Most of us will have some measurable sweat loss during workouts longer than an hour and, let's be honest, if you're reading this, you are most likely a cyclist or a triathlete and a bunch of your workouts will be long. 

Hydration is a must for most of your workouts. And if you are triathlete, you'll probably have days when you have more than one workout so re-hydrating and re-fueling after Workout #1 is important in order to set you up for Workout #2.

Drink Up! But When and How Much?

In a nutshell, you should be on taking in fluids throughout your day in one form or another. Yes, coffee counts but so does some of our food intake.  Some foods like watermelon and citrus fruit are higher in water content and that all helps replenish your hydration status as well as provide some delicious flavours and valuable nutrition.  But to keep it simple and straightforward, here are some simple suggested guidelines for hydration in and around training events.



Try to  be fully hydrated before you start.

Don't over hydrate.

Try for 400-600ml of water or sports drink before the workout.

During Workout

Try to replace sweat losses.

Try to get in 150-350ml (6-12 oz) of fluid every 15 to 20 minutes.

An electrolyte supplement like NUUN or X-Act will help replenish some of the sodium lost through sweat.  Electrolytes are important for your body to regulate fluid balance in your body.

Carbohydrates of 30 to 60g per hour are beneficial for workouts over 60 minutes.

Try to replace about 80% of fluid/sweat losses during training.

Post Workout

You are likely dehydrated after workouts longer than an hour and the hotter and more humid the environment, the more dehydrated you likely are.

Drink 500 to 700ml of fluid for every pound you lose in training.
Post workout replenishment should include more than just water, though, for optimal recovery and restoration of glycogen stores.  


 It might sound easy but with so many variables, it is impossible to have any one definitive measurement that will work for everyone. Even for one individual, and that includes you, differences in workout intensity, duration and environment will affect your hydration needs.  Monitor your fluid intake and post workout metrics and sensations for signs of dehydration:

Signs of dehyration:

  • Thirst
  • Reduced urine output and urine colour
  • Poor mood and dizziness
  • Fatigue
  • Headache
  • Decreased alertness
  • Loss of concentration

Some of these signs are general and can be due to other factors too.  You might feel fatigue just because you put in a long and hard effort in training. We all know headaches can be caused by so many other things.  Still, you know when you've put in a hard session and have sweated a lot, hydration is important and as easy as taking in some appropriate fluids.  

So, there you have some general guidelines on how to hydrate for your training.  Drink up!

 (photo credit Cats Coming)



Elise Gaudet
Elise Gaudet

Leave a comment

Comments will be approved before showing up.

Sign up for our Newsletter