The Register's Annual Great Bicycle Ride Across Iowa

2017 RAGBRAI

Top 10 Training Tips for RAGBRAI #5: Drink Before You Are Dry, or Sweat Happens

by Coach David Ertl

Hydration is an important consideration when riding a bicycle across Iowa in what is often one of the hottest weeks of the year! Your body is continually losing moisture through perspiration, respiration and urination.  We must continually replace this lost fluid to maintain proper functioning of our body. 60% of the human adult body is water while the brain and heart are composed of 73% water, and the lungs are about 83% water. The brain, heart and lungs are important, especially for cycling. When we sweat we lose not only water but also electrolytes. Electrolytes are minerals that are critical for the functioning of the body’s many reactions. The major ones are sodium, calcium, potassium and magnesium. So when replacing fluid we also need to replace electrolytes.

We are sweating all the time although at certain times it is more apparent than others.  Ride a bike in blazing sunshine during 90 degree weather and 90% humidity and you will be dripping wet.  But you also sweat a lot on dry days when you don’t feel sweaty, you just don’t notice it because your sweat dries so quickly.  Sweating cools the skin when it evaporates. This is why dry air (think Colorado) feels so much fresher and cooler than Mississippi (or Iowa) in the summertime.  The point is, you are losing a lot of moisture when you ride a bike, whether you realize it or not. To illustrate this point, weigh yourself before and again after a ride.  It isn’t uncommon to lose 2-3 pounds on a bike ride.  And this doesn’t even include the water you drank during the ride.

It is difficult to come up rules of thumb about how much to drink while exercising because all conditions are different, such as temperature, humidity, effort level and individual sweat rate differences. But first of all, it’s important to begin a ride fully hydrated. You should have had to use a restroom (or porta potty) just before your ride. This indicates your fluid levels are topped off.  Your thirst mechanism is good but it is not proactive. It doesn’t know you are going to be riding for the next 8 hours on RAGBRAI. So start sipping from your water bottle before you start feeling thirsty (drink before you are dry).  This is especially important on very hot days because if you get behind in re-hydrating, it can be difficult to catch back up. You should aim to drink at least one large water bottle per hour, and 2-3 when it is really hot.

But don’t just focus on water. You also need to replace electrolytes.  Most people think about salt but sodium isn’t enough. You also need the other electrolytes as well.  If you eat a balanced healthy diet, you probably get what you need, but when you are sweating heavily you may run low on some of these. Sports drinks, such as Gatorade and numerous powered products, contain electrolytes as well as water and sugar. So you might want to add sports drinks while riding on hot days. I don’t recommending taking salt tablets because these just replace sodium. Instead there are electrolyte tablets you can purchase to supplement with all the necessary electrolytes.

You also want to be aware that it is possible to drink too much water as well. There is a condition called hyponatremia where you drink so much that you dilute your sodium balance in your body, you literally drown yourself. Now this is a rare event and typically is only seen in extreme sport situations, but for some people, doing RAGBRAI is pretty extreme. This is another reason why you shouldn’t drink just water but include electrolytes.

Bottom line – Be conscious about staying hydrated and don’t just rely on thirst, and include electrolytes as well as water.

Bottoms up!

Coach David Ertl

David Ertl is a USA Cycling Level 1 Coach. He coaches the Des Moines Cycle Club Race Team, JDRF Ride To Cure Diabetes and individual cyclists through the Peaks Coaching Group. He also provides cycling training plans and ebooks at his website: http://www.CyclesportCoaching.com . He can be contacted at coach@cyclesportcoaching.com.

5 Comments

Tom, May 18, 2017 at 10:59 am

Pardon me but this is actually bad advice that can get people in trouble by overhydrating and then succumbing to hypernatremia. That’s why International Association of Marathon Medical Directors (doctors) recommend the simple guidance “drink to thirst.”

Heck even farm animals know enough to stay hydrated based on thirst mechanisms are humans really that stupid?

http://immda.org/wp-content/uploads/2015/08/Spring-2006-Updated-Fluid-Recommendations.pdf

Ken, May 18, 2017 at 12:09 pm

David Ertl has given us a balanced and reasonable presentation on hydration. He may err a little on the side of over-drinking but as long as you only over-drink a little and take some form of electrolytes you should be fine. The advice I have seen on line (yeah, I know) suggests that you are unlikely to get into hyponatremia territory if you stay at 2 liters per hour or less (however many “bottles” that is). In most cases that should be enough water although individuals and conditions vary. I think it is right to assume that your thirst will tell you if you need to exceed 2 liters in an hour.

Up until a few weeks after RAGBRAI last year I too thought this hyponatremia stuff was something that only extreme athletes would ever get into. But then a friend at work who is active and health conscious but nowhere near extreme told me out of the blue one day that he had just gotten back from the hospital after experiencing it. He was not doing anything extreme at all, just riding a bike at a modest pace on a hot day for a distance no more than we would ride during RAGBRAI. Less miles in fact than we will ride several days most years.

But being health conscious he had read all the advice on “drinking ahead of thirst” and he implemented that policy. He was not using a sports drink, wanting to avoid their calories. And he was not aware that you could get balanced electrolyte tablets so he wasn’t using those either. So he drank, a lot. When he got home he continued to drink, a lot, because he was thirsty and assumed that in spite of his drinking he had managed to dehydrate himself. He was treating himself for a condition he did not have!

Now, there was one more factor in play. Like many health conscious individuals he had put himself on a low sodium diet. The perfect storm was gathering, in other words, and it continued to build until he passed out and his wife called 911! I believe he had drunk something like 4 or 5 gallons of water over the course of an afternoon and evening. Hyponatremia is something that can happen to you so be wary of it. If you drink and drink and drink and cannot quench your thrist, as he did, it MIGHT be a sign that there is another problem that needs addressing. Eat some potato chips, borrow some electrolyte tablets, or use a sports drink in spite of the calories. You might be surprised to find your thirst going away. I know I have several times over my many decades of living been in a situation of having an unquenchable thirst and found that salty foods fix that right up. I’ve never had that issue since I started using electrolyte tablets and drinking to thirst.

Alan, May 18, 2017 at 2:39 pm

Coach is correct!!! Ignore his advice at your own peril. Ask anyone who was hospitalized for dehydration during RAGBRAI 2012. Symptoms of dehydration are a lack of thirst and no appetite when you should be thirsty and hungry. Been there once and don’t want to go back.

Lou, May 18, 2017 at 7:56 pm

RAGBRAI is an intensive ride because of the heat and humidity. Do not underestimate the heat! HEAT EXHAUSTION IS A LIFE OR DEATH EMERGENCY! Dehydration leads to heat exhaustion. If you see signs of heat exhaustion in someone, please stop to check on them and get help fast. Perhaps another rider is just not acting like themselves that day, feeling fatigued (weakness), muscle cramping, flush (red) face, excessive sweating. Those are all early indicators, followed by headache and confusion, then collapse. Another danger sign is profuse sweating that suddenly stops.

Electrolytes help your body to maintain water balance. Water delays/prevents heat exhaustion. If people wait to drink until thirst they are already behind the hydration curve. Hydration begins the evening before… I suggest to drink a liter of water at bedtime. Sure you might have to visit the KYBO in the middle of the night, but you’ll feel much better in the heat the next day.

My routine is differs from Coach Ertl in that I eat a low-carb fat-adapted diet. I don’t like sugary sports drinks because they upset my stomach. Instead, I drink one to two liters of water every hour with a Camelbak fizzy tablet. I take Hammer Endurolyte capsules, one or two in the morning and one every hour or two depending how I’m feeling. I supplement with a coconut water (sodium/potassium) or potassium capsule each night at bedtime. This works for me, YMMV.

People with heart and medical conditions should check with their doctors for individual needs.

Seth, Jun 1, 2017 at 6:50 am

Anyone telling you to drink ahead of your thirst, or claiming that sports drinks help you avoid over-hydration hasn’t read the science.

https://www.outsideonline.com/1900801/tim-noakes-serious-problem-overhydration-endurance-sports

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