Hydration Practices and Techniques
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FWIW, my plans for the next couple of months require that I do some real training in NC heat. So that is what I am doing. I have never been concerned about my ability to perform in heat WHEN HYDRATED - at least on a bike assuming the false wind that riding provides (other than maybe long climbs). I was just concerned about my body's ability to take in and process enough water.
At this point it seems that my estimate of how much water I can process was too low. Clearly once I get past the first hour, I can process more than 1.5 pounds of water per hour. And I guess I will find out soon enough as in 2 weeks I plan to ride the Tour de Moore (local century ride) as a training ride. If I have a problem in that regard, this should let me know for sure. Conveniently at about mile 75, the route goes within 3 miles of my house. If I have real problems - just ride it on home :-)
dave
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How to bicycle better in the heat.
Here is what I’ve learned from my 48+ years of riding in the heat. I live in Fort Worth, Texas. I’ve haven’t lived here my whole life . . . . yet!
Texas summers can be pretty hot, for sure. I’ve always done well in the heat, and I’ve been asked what’s my secret. I think the recipe for doing well in the heat is, ready for this, ride in the heat. Seriously though, I think my secret is riding 1 to 1.5 hours during the hottest part of the day. Do it two or three times a week. Don’t go longer than that during this “training” session. Pretty soon, your body will know exactly what to do when it’s hot. Most folks can endure this length of ride. It's short enough that dehydration shouldn’t be a factor. I’ve always commuted to work. I try to do it two or three days a week during the warm parts of the year. I am the worst cold weather wimp, I admit.
I recently had a good friend that bonked on a very hot weekend ride. I met him a few weeks later and he said he went to the doctor, and found out his pituitary gland wasn’t working right, and got a little pill to take and everything was better. This spurred my interest, and I started searching out just what your body does, when you exercise in the heat, especially riding a bike. Here is what I learned.
I admit that I may have some of the details slightly off, but the general facts stand true (I think).
Your hypothalamus resides in your brain. One of its jobs is to regulate your core temperature. It controls your heart rate, your breathing, your perspiration, directs blood flow, and blood quantity, among other things. When you’re riding in the heat, it chimes in and starts doing its magic. It maintains your core temperature plus of minus one degree. That alone is amazing, considering the outdoor temperature can range from below freezing to over 100 degrees. It keeps your core temperature at 97.6 to 99.6 degrees. WOW.
When you ride you bike, you generate heat. More heat than when your sitting on the couch watching the Tour De France. When you start getting hot, your hypothalamus tells your heart to speed up. It then changes where your blood goes in your body. Normally about 20 percent of your blood volume resides right under your skin, and 80 percent goes to your muscles, and everywhere else. When your riding in the heat, 80 percent is under you skin, and 20 percent is left to work your muscles and everything else. This is why it's impossible to perform as well in the heat – you simply don’t have enough blood to feed those bulging quads, and everything else.
Another thing that happens without our knowledge is, when it gets hot, the hypothalamus directs your body to manufacture more blood to help fill in the void left by all that blood that’s now under you skin.
It also directs the fluids in the cells of your body to go to the sweat cells and make your skin wet. Wet skin plus a little wind, equals cooling. In fact, as long as it's not too humid and you have ample fluid supply, your body’s air conditioner works pretty well. All that hot blood right under that cool skin will release the heat of your body. The blood gets cooled off a bit and returns to the core, and voila, your core gets cooler.
Everything works great, most of the time. But sometimes certain conditions can make things run amuck. Here are some.
Humidity! Humidity is your enemy. When the air is humid, and it's hot outside, the water on your skin won’t evaporate. Without evaporation, you have little or no cooling. You overheat!
Dehydration. Of course, you have to be hydrated to have enough water supply in your cells to sweat. Being dehydrated removes the water from this wonderful evaporation air conditioner, and, you guessed it. You overheat!
Here’s a little about hydration and dehydration. During a strenuous ride in the heat, you can only absorb about half the volume of fluid that you perspire out. It doesn't matter how much you drink. So you will be somewhat dehydrated after the event. The last time you performed well on a long ride in the heat, it probably had as much to do with how well you hydrated the day before the event, as it did the day of the event. So start the day before saturating all your cells in your body with fluid. A few years ago, I went to the Tour of California, and we stayed in the hotel where a bunch of the pro riders were staying. It was a small town, so after the days race, the Pro riders were walking around town. We noticed that every single one of them had a water bottle or two, and were drinking constantly. They were re-hydrating for the next days race.
Your body is amazing. It does all this stuff without us having to think about it. If we had a set of instruments and knobs, that we had to keep set right, we would all die – just because we forgot to lower the landing gear, or something.
Lastly, what happens if you push through the pain of heat exhaustion? I can assure you - YOUR HYPOTHALAMUS WILL STOP YOU! It has enormous power. You will slow down and stop, no matter how much will power you have. Trouble is if you go too far, you may carry it with you forever. Once you've had full blown heat exhaustion or heat stroke, you will always be more susceptible to the heat.
hope this helps
Steve
Here is what I’ve learned from my 48+ years of riding in the heat. I live in Fort Worth, Texas. I’ve haven’t lived here my whole life . . . . yet!
Texas summers can be pretty hot, for sure. I’ve always done well in the heat, and I’ve been asked what’s my secret. I think the recipe for doing well in the heat is, ready for this, ride in the heat. Seriously though, I think my secret is riding 1 to 1.5 hours during the hottest part of the day. Do it two or three times a week. Don’t go longer than that during this “training” session. Pretty soon, your body will know exactly what to do when it’s hot. Most folks can endure this length of ride. It's short enough that dehydration shouldn’t be a factor. I’ve always commuted to work. I try to do it two or three days a week during the warm parts of the year. I am the worst cold weather wimp, I admit.
I recently had a good friend that bonked on a very hot weekend ride. I met him a few weeks later and he said he went to the doctor, and found out his pituitary gland wasn’t working right, and got a little pill to take and everything was better. This spurred my interest, and I started searching out just what your body does, when you exercise in the heat, especially riding a bike. Here is what I learned.
I admit that I may have some of the details slightly off, but the general facts stand true (I think).
Your hypothalamus resides in your brain. One of its jobs is to regulate your core temperature. It controls your heart rate, your breathing, your perspiration, directs blood flow, and blood quantity, among other things. When you’re riding in the heat, it chimes in and starts doing its magic. It maintains your core temperature plus of minus one degree. That alone is amazing, considering the outdoor temperature can range from below freezing to over 100 degrees. It keeps your core temperature at 97.6 to 99.6 degrees. WOW.
When you ride you bike, you generate heat. More heat than when your sitting on the couch watching the Tour De France. When you start getting hot, your hypothalamus tells your heart to speed up. It then changes where your blood goes in your body. Normally about 20 percent of your blood volume resides right under your skin, and 80 percent goes to your muscles, and everywhere else. When your riding in the heat, 80 percent is under you skin, and 20 percent is left to work your muscles and everything else. This is why it's impossible to perform as well in the heat – you simply don’t have enough blood to feed those bulging quads, and everything else.
Another thing that happens without our knowledge is, when it gets hot, the hypothalamus directs your body to manufacture more blood to help fill in the void left by all that blood that’s now under you skin.
It also directs the fluids in the cells of your body to go to the sweat cells and make your skin wet. Wet skin plus a little wind, equals cooling. In fact, as long as it's not too humid and you have ample fluid supply, your body’s air conditioner works pretty well. All that hot blood right under that cool skin will release the heat of your body. The blood gets cooled off a bit and returns to the core, and voila, your core gets cooler.
Everything works great, most of the time. But sometimes certain conditions can make things run amuck. Here are some.
Humidity! Humidity is your enemy. When the air is humid, and it's hot outside, the water on your skin won’t evaporate. Without evaporation, you have little or no cooling. You overheat!
Dehydration. Of course, you have to be hydrated to have enough water supply in your cells to sweat. Being dehydrated removes the water from this wonderful evaporation air conditioner, and, you guessed it. You overheat!
Here’s a little about hydration and dehydration. During a strenuous ride in the heat, you can only absorb about half the volume of fluid that you perspire out. It doesn't matter how much you drink. So you will be somewhat dehydrated after the event. The last time you performed well on a long ride in the heat, it probably had as much to do with how well you hydrated the day before the event, as it did the day of the event. So start the day before saturating all your cells in your body with fluid. A few years ago, I went to the Tour of California, and we stayed in the hotel where a bunch of the pro riders were staying. It was a small town, so after the days race, the Pro riders were walking around town. We noticed that every single one of them had a water bottle or two, and were drinking constantly. They were re-hydrating for the next days race.
Your body is amazing. It does all this stuff without us having to think about it. If we had a set of instruments and knobs, that we had to keep set right, we would all die – just because we forgot to lower the landing gear, or something.
Lastly, what happens if you push through the pain of heat exhaustion? I can assure you - YOUR HYPOTHALAMUS WILL STOP YOU! It has enormous power. You will slow down and stop, no matter how much will power you have. Trouble is if you go too far, you may carry it with you forever. Once you've had full blown heat exhaustion or heat stroke, you will always be more susceptible to the heat.
hope this helps
Steve
Temperature cannot be maintained in the normal range during long events even in moderate weather. Marathoners, even competing in cool weather, routinely finish with core temps in the 100s, and the hypothalamus can do a lot to control temperature, but it can't stop you from going into the danger zone. Alberto Salazar once famously collapsed in a race and redlined the rectal probe at 107, a temp often enough associated with death. I don't know what happens to cyclists, but it's probably similar.
It's important to distinguish between fluid in cells and fluid in the circulation and to realize that exchange between these compartments is slow. Cellular fluid is not available for sweating. The sweat glands basically filter water and small molecules directly out of the circulation and squirt them onto the skin. Likewise, repletion of the cellular compartment takes hours of plasma dilution to drive water down the osmotic gradient into thirsty cells. For the sake of completeness, there is also a third compartment, the interstitial space (in tissues, between cells), which can hold large amounts of water and, finally, water is stored in the glycogen matrix and is released as glycogen is consumed.
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Go for a long ride in what would be considerate mild or moderate weather. Drink lots of water on the ride. When you get home, drink lots of water and eat as regular. Weigh yourself the next morning and in most cases, you will be one to three pounds lighter than usual.
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I put 5 nuun in a 3 liter camelbak 2 vitamin 3 non-caffinated sport. so 12 grams of carb for 3 liters while cranking 30-40 miles. those 12 grams likely get burned pretty fast.
I mix up a camelbak full the night before and let it fully fizz out. Extra belching.
12 grams of sugar over 3 hours isn't enough to trigger an obvious insulin response in me, but I'm also not fooling myself that I'm running on fat either.
I mix up a camelbak full the night before and let it fully fizz out. Extra belching.
12 grams of sugar over 3 hours isn't enough to trigger an obvious insulin response in me, but I'm also not fooling myself that I'm running on fat either.
Do you have trouble cleaning the bladder or hose? Nuun leaves a slight residue in my cups at home, seems like it could be a problem in a Camelback? I won one recently and have been thinking about whether or not to do what you're doing, so I'm real interested in how it works out for you.

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water water
On an all day ride when its over 100 degrees, I can lose 8 lbs. My normal weight is about 165. I can say that I am partly to blame because I don't drink enough. Good rule of thumb, if you don't pee the entire day, you probably aren't drinking enough. I saw a video of the BMC Team bus during the Tour De France. They had a little sign on the bathroom door with a full color "litmus test" If your pee isn't clear or very pale or, you are dehydrated. This shows that even the pros have trouble with dehydration.
Steve
Steve
Steve, thanks for the wealth of information. Very interesting.
FWIW, my plans for the next couple of months require that I do some real training in NC heat. So that is what I am doing. I have never been concerned about my ability to perform in heat WHEN HYDRATED - at least on a bike assuming the false wind that riding provides (other than maybe long climbs). I was just concerned about my body's ability to take in and process enough water.
At this point it seems that my estimate of how much water I can process was too low. Clearly once I get past the first hour, I can process more than 1.5 pounds of water per hour. And I guess I will find out soon enough as in 2 weeks I plan to ride the Tour de Moore (local century ride) as a training ride. If I have a problem in that regard, this should let me know for sure. Conveniently at about mile 75, the route goes within 3 miles of my house. If I have real problems - just ride it on home :-)
dave
FWIW, my plans for the next couple of months require that I do some real training in NC heat. So that is what I am doing. I have never been concerned about my ability to perform in heat WHEN HYDRATED - at least on a bike assuming the false wind that riding provides (other than maybe long climbs). I was just concerned about my body's ability to take in and process enough water.
At this point it seems that my estimate of how much water I can process was too low. Clearly once I get past the first hour, I can process more than 1.5 pounds of water per hour. And I guess I will find out soon enough as in 2 weeks I plan to ride the Tour de Moore (local century ride) as a training ride. If I have a problem in that regard, this should let me know for sure. Conveniently at about mile 75, the route goes within 3 miles of my house. If I have real problems - just ride it on home :-)
dave
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Thanks for the reply. I knew I would get some of the details wrong. Thanks for the correction.
One thing that makes cycling better than marathon running in my opinion is that generally, you are doing your work and generating nearly 20 MPH of wind. This is a huge advantage.
But watch out for humidity - it will always get in the way of your bodies natural air conditioner. One thing to get in the habit of noticing when you ride. Take a look at the weather. I use NOAA, and it lists the hourly temperature and humidity and most importantly, the dew point. Dew point is the best indication of whether you are going to be comfortable. Humidity varies wildly during the day, but Dew point does not. The general rule is that if the Dew Point is above 65 degrees, most will feel uncomfortable. Above 70 degrees, you will fill very uncomfortable. Below 65 most people feel the air is dry enough to enjoy. Below 60 and you feel refreshed. For me, this is the best indicator of whether there is too much moisture in the air to properly cool your body down, or not. For more information google Dew Point VS Relative Humidity. It is very meaningful for cyclists.
steve
One thing that makes cycling better than marathon running in my opinion is that generally, you are doing your work and generating nearly 20 MPH of wind. This is a huge advantage.
But watch out for humidity - it will always get in the way of your bodies natural air conditioner. One thing to get in the habit of noticing when you ride. Take a look at the weather. I use NOAA, and it lists the hourly temperature and humidity and most importantly, the dew point. Dew point is the best indication of whether you are going to be comfortable. Humidity varies wildly during the day, but Dew point does not. The general rule is that if the Dew Point is above 65 degrees, most will feel uncomfortable. Above 70 degrees, you will fill very uncomfortable. Below 65 most people feel the air is dry enough to enjoy. Below 60 and you feel refreshed. For me, this is the best indicator of whether there is too much moisture in the air to properly cool your body down, or not. For more information google Dew Point VS Relative Humidity. It is very meaningful for cyclists.
steve
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You are not wrong. The newer formulas are worse than the older ones too. I suspect the dextrose to be the culprit.
I bought the cheap knock off cleaning kit off of amazon. long skinny brush for the hose and a large one for scrubbing out the bladder. I put the frame in and actually put the whole bladder upside down with a clean wash cloth in the the omega opening to absorb any additional dripping. That is my weekly routine.
Once a month I drop 2 Aquafresh toothbrush head/retainer cleaning tablets in the bladder, fill it up and let it sit overnight. It gets the bladder very clean, but you need to rinse it out really well least your next ride your nuun has a bit of minty freshness to it.
I bought the cheap knock off cleaning kit off of amazon. long skinny brush for the hose and a large one for scrubbing out the bladder. I put the frame in and actually put the whole bladder upside down with a clean wash cloth in the the omega opening to absorb any additional dripping. That is my weekly routine.
Once a month I drop 2 Aquafresh toothbrush head/retainer cleaning tablets in the bladder, fill it up and let it sit overnight. It gets the bladder very clean, but you need to rinse it out really well least your next ride your nuun has a bit of minty freshness to it.
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This has to be one of the most entertaining threads ever.
So many near death experiences and so much hand wringing over drinking a little water while exercising.
It’s priceless
So many near death experiences and so much hand wringing over drinking a little water while exercising.
It’s priceless

#110
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Sounds like the words of someone who's never experienced heat exhaustion.
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Replace the word ‘months’ with the word ‘minutes’ and I think you summed it up nicely.
I’m just sincerely glad you made it home alive the other day when you stated you went 20 miles without water. And you only needed a full gallon of electrolyte water and a Starbucks to do so
I’m just sincerely glad you made it home alive the other day when you stated you went 20 miles without water. And you only needed a full gallon of electrolyte water and a Starbucks to do so

Last edited by downhillmaster; 08-21-19 at 05:00 AM.
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I haven't drank Starbucks in years.
I also don't need to troll people for having common sense to feel better about myself.
I also don't need to troll people for having common sense to feel better about myself.
