Another urine discoloration possibility: rhabdomyolysis with myoglobinuria. Muscle tissue destruction with excretion of muscle-iron moleculesin the urine. Dehydration plus exercise may cause this, and it in turn may cause kidney damage. Recently saw such in an aging jock who took a spinning class-resulting in incapacitating thigh cramps, discolored urine, and hospitalization for aggressive rehydration and monitoring of kidney function. happy ending, by the way. hydrate or die, and some of the deaths are prolonged, messy ones.

Red urine is not always blood.

Red or pink urine
Despite its alarming appearance, red urine isn't necessarily serious. Causes include:

* Blood. The presence of red blood cells is the main reason urine turns red. Usually, bleeding isn't severe and occurs without other signs or symptoms. Factors that can cause urinary blood, known medically as hematuria, range from strenuous exercise, urinary tract infections and an enlarged prostate to kidney or bladder stones, kidney disease, and, occasionally, kidney cancer or bladder cancer.
* Foods. Beets, blackberries and mom's rhubarb pie can turn urine red or pink.
* Medications. Certain laxatives — Ex-lax is an example — can cause red urine. Prescription drugs that have the same effect include antipsychotics such as chlorpromazine (Thorazine) and thioridazine and the anesthetic propofol (Diprivan).
* Toxins. Chronic lead or mercury poisoning can cause urine to turn red. This may be the result of high levels of excreted porphyrins, the same pigments that discolor the urine of people who have porphyria.

I agree with Mike. However if I can throw in one possibilty - They use anticoagulation catheters to take blood. If that particular catheter had excessive amounts of this, it could have "thinned his blood" on top of being dehydrated- on top of extra exersion ect... just a thought.

When I used to do chart reviews, I was always struck by how many patients were quite dehydrated when they finally arrived at the hospital.

But, for day to day living, research has determined that it's probably wisest to drink when your thirsty, and not ingest copious amounts "just to be sure".

However, while vigorously exercising (especially in the heat) dehydration can occur very quickly, so it is prudent to ingest water at regular intervals (i.e. sip the camelbak).

This forum has hashed and rehashed electrolyte replacement to death, but it does bear repeating how important it is to hydrate.

I get chills when I read the stories of desert travelers dying from dehydration/heat stroke with water still in their canteens.

As Doug says, store water in your stomach!