K50 said:
Wow that's starting to sound sort of like the argument I used in my first post. I wish Synpax were here to see this.
I have to weigh in here. Aside from the bitter personal attacks from one writer to another, there has been some statements made that should be addressed and none yet have had any scientific or medical basis. I’ve personally done searches on Pub Med and Scifinder Scholar (two of the best science and medical search engines out there) on this topic and found nothing substantial on this topic as it pertains to a healthy adult during or after exertion.
If you're talking about atrial fibrillation being induced by drinking cold water (even ice) you're talking about 1-3% of the population being susceptible to such a condition. I think almost always, in those cases people experience premature ventricular contractions (PVCs) for a pre-existing condition and cold water (along with a hundred other stimuli) may occasionally induce PVCs. It's exceptionally rare! If you're talking about submergence into ice water, that can in fact lead to PVCs in a healthy person under the right circumstances but still not in every case and generally not immediately. But you’re talking about the difference between the heat capacity of 120mL (4 oz) and 56L (15 gal) of water. The swig of water someone takes can only cool down a small amount of tissue before it reaches body temperature. Most of the benefit is psychological because the water warms up so fast in the body. The same is true for people drinking warm water. While drinking hot water might make you sweat more on a warm day, and in turn make you feel cooler because you’re sweating more, the effect is very negligible and again mostly psycological.
You’re correct in the fact that the cold water will absorb heat from the stomach tissue and esophagus. However, heat is not energy it’s a form of entropy, so it’s a byproduct of energy spent driving the muscular contractions throughout the body and the sun beating down on you. The distinction is only necessary so a novice athlete doesn’t think they’re burning calories trying to stay cool. That being said, as mammals our bodies operate best within a small range of temperatures, so the heat within the body must be regulated to make the body operate correctly. And yes, the heart is one of the most susceptible organs to deviations from this temperature range so in cases of heat exhaustion and hypothermia the first critical signs are generally observed in the heart.
If you’re body temperature is way above normal because of heat exhaustion most hospitals will first give you an IV of chilled saline solution, pack you with ice, or submerge you in an ice bath (or just cold water) to drop your body temperature. I don’t think we’re talking about being that far gone though. If you’re to that point you should just drink whatever you’ve got on hand so you can keep sweating and call an ambulance before you pass out.
Another point is that the temperature of the water consumed should not affect the amount you’re sweating or your electrolyte balance. As I mentioned before, the water you’re drinking doesn’t have enough heat capacity to significantly drop your body temperature (unless you’re talking about chugging a gallon of ice). If you buy an intro to physics textbook you can do a pretty simple calculation of how much water you need to drink to absorb enough heat to drop your body temperature by just 2 degrees. It’s over a gallon of water! If you do that you need to worry about a lot of other complications.
However, the first post was right in that it said “So the moral here is....Water temperature is not THAT important.” I would take that further and say water temperature doesn’t matter at all (unless it’s too hot for you to pallet). Personally I will freeze a bottle of electrolyte drink (so it’s well below the freezing point of water) before a long, hot ride and drink that until it melts away in the first couple of hours. The main thing is to drink and drink often when it’s hot. If you have a heart attack on the bike I would dare say it had nothing to do with the temperature of the water you drank.
This isn’t a bad topic to bring up though, since I’ve seen people suggest similar things on other forums. The amount of misinformation is abundant out there so don’t trust everything you read on websites or in different forums. Remember, there’s no peer review for what gets posted to the web.
Oh and beer in a camel back… bad idea.
Them's might be fighting words lol...But only Kokanee is good, Molson is bad.
