Wonders of Water

Water is the largest component of the human body and the primary component of all body fluids.

The main sources of water for the human body are:

  • Pre-formed Water: Ingested liquids from food and drink that have been absorbed through the gastrointestinal tract.
  • Metabolic Water: Produced via dehydration synthesis reactions of anabolism.

When more water is lost than gained by the body, the resulting dehydration stimulates thirst by decreasing saliva production, increasing osmotic pressure, and decreasing blood volume which causes the kidneys to release renin, stimulating the sensation of thirst in the hypothalamus. When the sensation of thirst increases, a person’s resulting consumption of water restores normal fluid volume. Water movement in and out of body compartments is primarily due to osmosis. Electrolytes help control the process of osmosis and maintain acid-base balance for normal cellular activity. Electrolytes also carry electrical currents, which controls secretion of certain hormones and neurotransmitters.

Sweating results in loss of fluids that impact physiological function. Obviously, that’s why replacing fluids during strenuous exercise is important. Dehydration can have a very negative impact on physical performance and adequate fluid intake during exercise assists in replacement of intracellular water. The benefits of proper hydration during exercise can include increased blood volume, lower core temperature, and reduced muscle glycogen use. These and other factors combine to maintain performance levels over the duration of prolonged physical exertion.

Here’s a study that evaluated effectiveness of hydration on work capacity and physical stress on groups given plain water, sports drinks, or no liquid at all:

ACUTE PHYSIOLOGICAL RESPONSE TO INDOOR CYCLING WITH AND WITHOUT HYDRATION; CASE AND SELF-CONTROL STUDY. Ramos-Jiménez A, Hernández-Torres RP, Wall-Medrano A, Torres-Durán PV, Juárez-Oropeza MA, Solis Ceballos JA. Nutr Hosp. 2013 Septiembre-Octubre;28(5):1487-1493. Department of Basic Sciences. Biomedical Sciences Institute. Autonomous University of Ciudad Juárez. México. http://www.ncbi.nlm.nih.gov/pubmed/24160205

“Oral rehydration drinks help maintain physical capacity and hydration during exercise… Liquid intake with or without electrolytes does not affect work capacity, and they are equally effective as hydration sources during 90 min of InC at strong and very strong intensities. Body temperature is the most sensitive variable detected by the subject’s hydration status during exercise.”

Water proved equally effective as sports drinks for hydration, maintaining body temperature and work capacity. Exciting to me because water is less expensive than sports drinks (just kidding, sort of). But this isn’t to minimize the role of sports drinks, as sodium replacement is occasionally necessary as well for proper electrolyte balance, particularly during physical exertion in hot temperatures. Sodium is crucial for not only conduction of impulses in muscle and nervous tissue, but it also assists in maintenance of fluid and electrolyte balance by creating extra-cellular fluid and osmotic pressure.

The human body functions better when it’s properly hydrated. This is especially true of muscle cells. I suggest you do what I do and carry a bottle of water with you wherever you go. Sip it at the first signs of thirst. There’s never, ever any advantage to letting yourself become dehydrated, however there are myriad negatives to that equation. May I also suggest that you invest in a quality water filter and a BPA-free bottle to minimize potential toxins. In an increasingly polluted world, it’s worth the effort to make sure your water sources are as clean as possible. Because if you’re smart — and, ahem, I’m sure that anyone reading this blog certainly must be pretty damn smart — you’ll be drinking a lot of it.

Sources

ACUTE PHYSIOLOGICAL RESPONSE TO INDOOR CYCLING WITH AND WITHOUT HYDRATION; CASE AND SELF-CONTROL STUDY. Ramos-Jiménez A, Hernández-Torres RP, Wall-Medrano A, Torres-Durán PV, Juárez-Oropeza MA, Solis Ceballos JA. Nutr Hosp. 2013 Septiembre-Octubre;28(5):1487-1493. Department of Basic Sciences. Biomedical Sciences Institute. Autonomous University of Ciudad Juárez. México. http://www.ncbi.nlm.nih.gov/pubmed/24160205

Fox, Stuart. “Human Physiology.” Mcgraw Hill. 2008.

Sherwood, Lauralee. “Human Physiology: From Cells to Systems, Edition 7.” Cengage. 2008.

Widmaier, Eric P. “Vander’s Human Physiology: The Mechanisms of Body Function, 12th Edition.” Mcgraw Hill. 2010.

Advertisements