Full on summer is just around the corner and with it brings that awful humidity. I know some of you crazy cats love it. Boooooo! With Arkansas summer closing in fast it’s time to adjust your thinking a bit. When to ride. Planned water stops. Pre-ride hydration. Check out this interview with Dr. Rankin on hydration. Be smart this summer folks and steer clear of dehydration!
OCA: How does the body lose water?
JR: When exercising, the two primary mechanisms by which you lose water are through perspiration and respiration (and yes, your body does still produce urine so we can add urination to this list as well). The rate at which one loses water through these processes varies from person to person and depends on things like overall fitness, body composition, and environmental factors (i.e. temperature, relative humidity, and altitude). Overall, we as athletes (myself included) tend to underestimate our fluid loss and, therefore, our fluid replacement needs during exercise.
OCA: What are the symptoms of dehydration?
JR: Well this depends on the degree of dehydration. Initially, things like dry mouth, excessive thirst, fatigue, headache, dry skin, and decreased urine output develop. In more severe instances, these can progress to low blood pressure, rapid heart rate, fever and then delirium and/or unconsciousness.
OCA: What are some of the more severe things that can happen if you don’t hydrate properly?
JR: A few things that come to mind are acute renal failure and circulatory collapse. If not treated accordingly, these can result in permanent damage to your body and, in extreme cases, death.
OCA: Any personal experience with dehydration?
JR: Well I’ve had several patients with it. I remember one instance when I was in training when a colleague of mine had a young girl (in her teens) that was overly aggressive with her fluid replacement and immediately drank A LOT of water after a 5 or 10K. She became very ill because she dropped her sodium level way too low due drinking plain water at a high rate.
I myself became moderately dehydrated during an IronMan. Despite my attempts at staying ahead on my fluid and electrolyte intake, when I was running my legs cramped up pretty bad forcing me to stop and walk for a bit until things loosened up. Then upon finishing the race, I was very nauseated, had a headache, and was pretty weak. I tried to catch up with just drinking fluids but could tell I wasn’t making much progress as it was making me more nauseated. I ended up in the medical tent and had to get some IV fluids.
OCA: As a triathlete what are some things you do to stay hydrated when you are competing?
JR: This depends on the distance of the race and the temperature/humidity in which I’ll be racing. Generally, the day before the race I tend to only drink water, as I really don’t need the extra carbs/sugar in some sports drinks on that day. On the day of longer races, early before race time I start drinking Gatorade in an effort to provide some substrate as well as fluids for the race ahead as well as replacing the fluids lost due to what I call “nervous pee” (dang those pre-race jitters). Then I select a hydration supplement on the bike that I’ve trained with and to which I know how my body will react that will provide me with a good balance of fluid, electrolytes, and substrate. Now, without having to get into all the biochemistry and physiology of fluid/electrolyte balance and how the addition of carbohydrates to fluids slows gastric emptying which decreases fluid absorption by the small intestine yet increases glucose absorption based on the glucose concentration of the fluid ingested; (Wow..really?) Suffice it to say I stick to fluid replacement that I can sip frequently to the point I don’t feel uncomfortable (bloated) but that’s not so sugary that it prevents water from getting absorbed quickly. I have found things like Skratch hydration mix and sometimes watered down Gatorade seem to work well for me personally (disclosures: I’m not a sports nutritionist and I have no affiliation with Skratch or Gatorade; I only know what’s been helpful to me while training and racing and for some reason right now I’m hearing Adam Sandler saying something about high-quality H2O). When I’m on the run, I really don’t like carrying a bottle, so I’m forced to take in whatever is available at the aid stations. I try to stop at every one of them and take a cup of water and a cup of sports mix (as well as a GU or other source of calories).
OCA: What are the benefits to staying hydrated?
JR: So much of your body’s performance is based on processes that are dependent on water. These include removal of toxins from your vital organs and delivery of nutrients to the cells in these tissues. During competition, these processes can be adversely affected leading to decreased performance.
OCA: How much water should we be drinking?
JR: That’s a simple question with no simple answer. This again depends on exertion levels and environmental conditions. I’ve come across various calculators that try to take into account your ideal body weight and the like. I’ve always heard the old “8 by 8” rule (eight 8oz glasses of water per day). That corresponds to about 1.9 liters a day. I guess for the general population that would be okay, but personally I’ve found that to be a little conservative. On days when I’m not doing a whole lot of training, I would guess I’m taking in around 3 liters of fluids at least.
OCA: Staying hydrated seems to be uniquely personal. I know I have had to experiment over the years with drink mixes, ratios and quantities. I have only in the last couple years figured out a good system after consulting a former pro cyclist. What system and products do you use to stay hydrated? I’d love to hear about it. Leave a comment below.
I encourage everyone to do your homework when it comes to hydration for your health & performance. A big thanks to Dr. Rankin for the interview and providing some helpful tips. Now get outside Arkansas!
To see my previous post with Dr. Rankin click here.
Looking for a doctor who understands the athletes’ lifestyle? Check him out, click here.
Dr. Joshua Rankin
FirstCare Family Doctors – Tontitown, a MANA Clinic
171 N. Maestri Rd.
Springdale, AR 72762
Not that picky about what I am drinking, just that it needs to be COLD. Besides it being more refreshing, I have heard that cold water is absorbed faster by the body.
fluid temperature has no proven effect on internal absorption, but does have an effect on palate. for more scientific information on re-hydration and fluid see the following:
according to most research water tonicity (osmotic pressure, or pressence of solutes on either side of a membrane ) effects absorption in the GI tract . the two companies that address this concept specifically for cycling have been skratch and osmo, with osmo taking a more detailed scientific approach to targeting fluid replacement.
i think it is important to recognize that even the best research points to wide variability in individual absorption rates.
Good chatting with you the other night. I’ll check out the article. Thanks!
Always enjoy your interviews with Josh. The humidity right now affects me more than the heat. I can’t take in enough to cover what I’m losing since the body can only absorb so much and I’m a heavy sweater. When I was Ironman training I would weigh myself before and after training, especially in this type of weather, and factor in what I consumed to figure out the net difference to see what I needed to adjust.
I’m in the same boat. I can lose several lbs easily on 1-2 hour ride. I have to up my fluid intake to 2 bottles per hour if I’m doing longer rides when it is this humid. But as I’ve gotten older I just dial it back in August and go earlier or late.