Understanding hydration and the different ways to fuel your body

We have all been there at one point in time if we consider ourselves serious about cycling. That moment in time where the “Wall” blind-sides us and our fun adventure becomes more of a quest for survival than domination. Cramps set in at the worst possible time, your energy is zapped, and your strength completely fails you. It becomes your own hideous jaunt through the hurt locker, and you start to wonder why you even got on the bike in the first place.

Nobody ever wants to gloat to their buddies back home after a long weekend of riding when they spent 5 hours in agony trying to get back to their car because they missed the mark on nutrition. It's way more fun telling stories about how your goals were smashed and you dominated literally everything.

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You can dominate your goals every day once you have the mystery of nutrition solved. But first, It’s worthwhile to spend some time understanding hydration and how it relates to us as we ride.

Some of you know what I am talking about.  I once finished the last 30 miles of a Fondo suffering from aid station to aid station, eating chocolate muffins and bananas and trying to wrangle enough energy out of my body to make it over the remaining hills! When I finally finished my first century ride, the 108-mile Fondo with over 5200 feet of climbing, it was not in a sprint, it wasn’t even in a bunch!  However, crossing the line was something I will never forget.

There were a few things that kept me from my goal, and we will be looking at those things today.  You always, always, learn from experiences where you fail.  What you learn makes you smarter and gives you more confidence and experience for future events.  Like that time, I tried my first triathlon!

Maybe you need to learn not to get so amped up in the peloton that you go full gas for the first forty miles as I did.  Your own time trial followed by a 20-mile lead out to the wall of suffering.  Maybe it’s something less physically demanding and more constructive, like what to eat early on and what energy solution to finish with.  The only questions not worth answering are those you are still learning to ask.

So, what can we learn as cyclists about hydration?  What is hydration? Is hydration as crucial as everyone says it is?  And most importantly, how can a study into hydration help you reach your goals? To answer these questions, we must have an overview of what can happen if we fail to hydrate, or we don’t hydrate enough.  And, for that answer, we need to look at what dehydration tell us.

What is dehydration?

Dehydration also causes a decrease in blood volume, which causes your blood to get thicker!  Thicker blood decreases your heart’s ability to supply fuel to your muscles. It’s interesting to note that your blood is also shared between your heart, your muscles, your lungs, and your skin in the process of sweating. Your body draws a lot more energy than you would think when riding hard on either mountain or road.

Fact – A quart of sweat contains about 845mg of sodium which is 37% our daily recommended value for consumption

Fact – A quart of sweat contains about 115mg of potassium which is 2.5% our daily recommended value for consumption

What bodily functions lead to dehydration?

Breathing:   When you inhale, the air you breath is heated or cooled by your lungs, which are moistened by your body at a relative humidity of 100%. The water in the air you exhale is lost to the environment.

Sweating:    Studies show that athletes can lose 2 quarts of water per hour, and your body temperature rises about 3 degrees during a strenuous workout.  Sweat contains 99% water and small portions of carbs, salt, protein, and urea.  It is also good to point out here that sweat does not release any of your body’s toxins, which is a common misconception.

The Natural Break:   We lose water through frequent bathroom stops.  Your Kidneys are a natural filter for your body, and you can check your hydration level by the color of your pee.  If it’s clear you’re good to go, if it’s dark yellow or amber, it would be a good idea to drink more water.

Digestion:   Water keeps the food you eat moving through your intestines, and you will lose about 6% of your body water through bowel movements.

Diet:   The food you eat could contribute to dehydration.  Heavily Processed foods, meat proteins, Diuretics like coffee and alcohol take more water from your body in the digestive process. https://www.waterguys.com/blog/body-lose-water/

How can you tell if you’re getting dehydrated?

Early signs of dehydration are found when you realize you’re thirsty.  By the time you get thirsty, your body has already lost 2% of its water.  What’s even more dramatic is that you could have a performance drop of up to 10% when you get to that point.

Eric Sternlicht has this to say: The bodies thirst mechanism is very poorly regulated, says Eric Sternlicht, Ph.D., a professor of kinesiology at Chapman University and a two-time masters time-trial national champion.  He says that you start feeling thirsty after your body has already lost two percent of its total water volume, and by that point, the literature has shown that performance drops by up to 10 percent.  [Shilton, A.C. (2018 May 9). How dehydration affects your ridding and tips for avoiding it. Retrieved from https://www.bicycling.com/training/a20027533/how-dehydration-affects-your-riding-and-tips-for-avoiding-it/]

It gets worse when you notice your lips are dry, or you stop sweating, or you start to develop a headache. Your goal then should never be to allow dehydration to get that far, because your brain, like your body, is mostly water. Your brain is 80% water.

If you are new to the sport or even a seasoned veteran looking to start endurance races like I am, learning how to combat dehydration is a vital piece of the puzzle. The above overview of dehydration should at least give you an idea of where your body is losing water and where you need to make nutritional changes to drive your fitness to the next level.

How do you determine how much water you need?

It’s fine by me if you are determined to drink a gallon of high quality H20 an hour.  Chances are, you will suffer the same terrible ride. Sternlicht would add: A good, basic rule of thumb to follow is the American College of Sports Medicine’s guidelines. The organization suggests that cyclists take in eight ounces of water every 20 minutes. According to the ACSM, drinking an electrolyte-enhanced sports drink that is six to eight percent carbohydrate will result in better and faster rehydration. Active transport proteins in the intestinal tract move carbs very quickly into the bloodstream, says Sternlicht, adding that water molecules follow closely behind these carbs. [Shilton, A.C. (2018 May 9). How dehydration affects your ridding? and tips for avoiding it. Retrieved from https://www.bicycling.com/training/a20027533/how-dehydration-affects-your-riding-and-tips-for-avoiding-it/]

The best way to obtain an estimate of how much fluid you need to drink is to conduct a 60-minute sweat test. Having hydrated well during the day, weigh yourself in the nude and write down your body weight. Go out and ride an average intensity for 60 minutes without taking in any fluids during the ride. As soon as you get back home, strip down, towel off and weigh yourself again.

The difference in the two measurements in ounces will equate to the total loss in ounces. These results will naturally vary with weather conditions and riding intensity. You may want to perform this test in several situations and correlate the results to get an accurate account of your fluid needs. Most riders will find that they will typically lose 16 to 32 ounces per hour.

I would never ask you to do anything or offer any advice until I have a chance to put it to the test. Here is what I found for myself. The honest answer is this:  I will be updating this post when the weather here in Breckenridge Colorado warms up to a point where I can sweat.

Yesterday I rode 14.69 miles on my road bike with 479 feet of climbing in an out and back from Breckenridge to Frisco on the rec path. I weighed in before the ride at 126.4 lbs. and the outside temperature was around 60 degrees for the duration of the ride.? I hit a bit of weather in Frisco had a slight tailwind on the way out and rode into the wind on the way back. I did not make a moderate effort, I drilled it, boomerang saliva, and the whole bit. Even with the headwind on the way back, I averaged 19.7 mph and finished in just under 45 minutes.

I was stoked with it being my first road ride of the season! Three weeks earlier I spent 3 days mountain biking in Moab which included my 2nd mountain bike ride of the season. I have been doing strength training for the last month and a half. Here is where it gets exciting, and the reason why I need to do this test again.

I did not sweat! So, when I weighed myself thinking that the other factors listed above would remove water from my body composition, I was wrong. It’ll take more research, but I believe the other factors will seriously matter in endurance events but not during a short test like this. My final weight after my ride was 126.4 lbs!

Here is what we are learning

Our body’s ability to break down carbs and transport water in our system are unique to each of us. If we want to understand our bodies requirements more, we need to perform a solid 60-minute sweat test multiple times. We are also learning that carbohydrates in addition to water, will increase the rate of rehydration, which will give you access to those carbs quicker through metabolization when they are in the right formula.  This means you will ride faster with less pain.

When I lived in Phoenix, Arizona, I stopped drinking energy drinks out on the trail and switched to water and sports bars or gels.  Yes, at one point I used to ride with only Gatorade, and I really paid the price.  Please don’t be that guy. I didn’t know about the different concentration of gels out there, and I only knew from experience that hydration drinks caused dehydration and would destroy my hydration bladder.

In my own ignorance, I was doing it all wrong.  Now, 20 plus years later, I use a combination of water, sports drinks, powders, energy gels, and bars. This solution works well for me and doesn’t destroy my gut during the ride in the process.? Let’s get into the nitty-gritty and introduce you to what I am using that is making the most difference.

When you think about needing to fuel on the bike there is are always external hazards that require your undivided attention, like traffic or technical bits in the trail. You will gain comfort and experience over time when you start to fuel in these conditions. You can’t forget about fuel, or you will be left with energy or hydration problems down the road. You may find yourself in a deficit, and you will get dropped. A regular gel requires a bit of water to unlock the absorption rate, bars are the same way. I use regular energy gels and isotonic energy gels along with bars and hydration powders.

How does your body fuel it’s muscles?

Your muscles draw energy from fat and carbohydrates to keep you on the move as you recreate or go about your healthy life. Your body will require higher concentrations of both fat and carbohydrates when you are competing. You might be wondering why fat takes so long to burn if it’s part of your bodies fuel. This is because fat is a slow burn compound, and carbohydrates are much faster to convert to energy.

Your body can also only store only a limited amount of carbs in your muscles so the higher the effort then, the more frequent you will have to consume carbs to maintain your own level of carbohydrate absorption. You will see your fat stores deplete over time, but it will not be as quick as you feel your energy dive due to lack of carbs. Let’s dive into what works and what people use on the road or trail.

It’s always good on the environment if you keep the wrappers of these things in your pockets after they are used. Nobody wants to see your discarded wrappers on the ground. Especially the wild animal who dies because its digestive system is clogged by your wrapper. Trash is a severe issue that requires each and every one of us to be custodians of the environment, each doing our part to manage the beauty we see out there each and every day.


There are two types of gels.? Isotonic gels that are designed with the proper constitution of water and carbs to allow the absorption rate to work immediately without the use of additional water. And regular gels that require extra water to assist with the absorption process into your body. If I were using both types of gel, I would use the regular gels early on when I had plenty of water to wash dilute them with and use the isotonic gels later when water was at a premium. You can use one or the other too, It is your nutrition design after all. I will be using the SIS gels this year as they fit more with my nutritional goals.

Last fall, I used the SIS Go Energy gels for the first time, and I am a believer in this packaging for release approach. The water and carbohydrate mix ensure that I am not wasting my water to absorb and deliver carbs to my muscles. After over an hour and nearly 1500 feet of climbing along my 24.5-mile rec path loop, I needed an energy boost. This happened at around 18 miles of the look after I had completed all the climbing.

I used the SIS Energy and Electrolyte Raspberry sachet as fuel with no additional water as I had nearly depleted my water bottles. The final 6 miles felt as good as the beginning of the ride, and my finish was strong as well. Usually, by the end of this particular ride, I get gassed because the 6 miles back is a slight uphill.

The general rule of thumb is 1 gram of carbohydrate per kilo, which will translate to around 58 grams of carbs per hour for my body weight of 127 pounds. Consuming too many carbs will mean they will go to waste or could sit in your stomach and make you sick. Some manufacturers mix their glucose with fructose, and research shows that this can increase absorption to 90g per hour.

Science In Sport Energy Gel Pack, SIS Energy Gel + Electrolyte, 22g Fast Acting Carbs, Perfomance & Endurance Gels, Raspberry Flavor – 2 Oz.

  • 22g Fast acting carbohydrates
  • 87 Calories
  • 54mg Magnesium
  • 18mg Potassium
  • 477g Electrolyte Blend
  • The Isotonic formulation means you don’t have to consume any extra water for digestion

Science in Sport Energy Gel Pack, SIS Energy + Caffeine, 22g Fast Acting Carbs, Performance & Endurance Gels, Berry Flavor – 2 Oz.

  • 22g Fast acting carbohydrates
  • 90 Calories
  • 75mg Caffeine
  • .04g Salt
  • The Isotonic formulation means you don’t have to consume any extra water for digestion

Gu Energy Roctaine Sea Salt Chocolate (24-Count)

  • 1425mg of Amino Acids help decrease muscle Damage
  • 100 Calories
  • 35mg Caffeine
  • 180mg Sodium


When it comes to bars, there are a couple different bars I use. I usually stay away from bars on my rides unless I am doing a long recreational mountain bike ride over 3 hours. Bars are harder to crew while expending a big effort, and they take longer to digest, and you will need to consume water for the digestive process. Usually, this is not a problem when you are not racing, but when you are racing, you need things you can get down quickly on the bike. However, If I was to swing by an aid station and the speed was somewhat slow, I would take time to grab a bar or something else substantial to add to the base of food in my stomach.

Sometimes if you take on a lot of gels on an empty stomach, you may get sick, and that will cause you to have problems during the race. If you are not racing, then you have nothing to worry about. If you are out on the trail more than a few hours, then a bar would be a great addition to your nutrition plan, assuming you still have plenty of water. Although I have used the SIS bars and find them interesting, I really like the variety and contents of the Cliff Bars listed below.

Science In Sport Go Energy Bar – Red Berry Flavor

  • 25g  Carbohydrates
  • 5g  Protein
  • 140  Calories
  • 12g  Sugar
  • 35mg  Calcium
  • .8mg  Iron
  • 135mg  Potassium

Cliff Bar – Energy Bar – Blueberry Crisp – (2.4 Ounce Protein Bar)

  • 260  Callories
  • 7g  Fat – (1g Saturated Fat – 2.5g Polyunsaturated Fat – 3g Monosaturated Fat)
  • 230mg Sodium
  • 250mg Potasium
  • 40g  Carbohydtrate
  • 4g  Fiber
  • 11g  Protein
  • A great listing of Vitamins and Minerals


Hydration Powders are also a good source for hydration when you ride as well. If you ride with 2 bottles as I do, the second bottle is a great candidate for a hydration powder. One water bottle needs to be straight water but feel free to play around with the dilution and find a fluid program that works for you. During training rides, you can quickly determine if you will need to add a hydration powder or not to your nutrition plans. On my mountain bike, I generally like to do long rides over the passes in Summit County and could be on the trail for more than 4 hours. I can fill my camelback with fresh water and bring another bottle along in my water bottle cage with a hydration solution. This works best for me.

I have learned not to use any powders or tablets in my packs water bladder because they are hard to clean. Because I have moved over to some of the SIS gels, I also use their hydration powder as well, and I will link it below. Since I have been using a combination of hydration powder, gels, and bars, I have not run into issues with hydration on the trail or any of my long rides. I am still trying to get my race nutrition dialed in, but that is where the nutrition side of cycling gets really interesting and fun. Please let me know what you use or if you have had similar success using the nutrition I have recommended above.


Science in Sport Go Electrolyte Energy Drink Powder – Lemon and Lime Flavor Sports Performance and Endurance Supplement – 1.25lb

  • 36G  Carbohydrates
  • 520mg  Salt
  • 60mg  Potassium
  • 25mg  Calcium
  • 998mg  Electrolyte Blend
  • 31g  Maltodextrin

Skratch Labs, Drink Mix Sport Hydration Lemon Lime, 15.5 Ounce

  • 80  Calories
  • 380mg  Sodium
  • 21g  Carbohydrate
  • 39mg  Magnesium
  • 39mg  Potassium
  • 44.3mg  Calcium

There is no doubt that supplementation is needed more than ever for you to succeed in your endurance goals on the bike and elsewhere. Chances are, you know this already, and that is why you are here. If you are new to the sport or even a seasoned veteran enhancing your skills, these products will help you along the way. I had been riding for years before I started seriously looking at sports nutrition. At the time, I had been entered into a Medio Fondo by my friends, and I had never ridden my road bike over 50 miles. I learned that I could not make it with just water and cliff bars. I needed something that absorbed quicker into energy and hydration.

These products work for me, and I have been using them in MS150’s, long road rides in Summit County, and long mountain biking trips over the passes, and along the single track here in Breckenridge Colorado. If they can work for me at 9800-foot elevation, and over passes that are 12,500 feet, they will work for you wherever you may be. Thank you so much for reading this far, and I wish you success in your nutritional planning so that you can go out and smash your goals. Get out and ride and stay safe so you can ride again tomorrow, there is nothing better!

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Brian Koehn

Breckenridge, Colorado

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4 years ago

Awesome post! Keep up the great work! 🙂

4 years ago

Great content! Super high-quality! Keep it up! 🙂

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