The physical benefits of good hydration
Zachary J. Schlader, PhD, FACSM
Most of the human body is water. By balancing fluid intake (i.e., drinking) and fluid output (e.g., urine production, sweating), the human body has well established mechanisms to maintain appropriate levels of body water. Despite this, there are many instances in which the level of body water can become inadequate. Arguably the most common situation of which is when body water is lower than ideal. This occurs when fluid intake is less than fluid output, which results in a physiological state that is described as being hypohydrated.
Preventing hypohydration is essential for health and necessary for optimal functioning of body systems. But what does this mean? On a fundamental basis, adequate body water is necessary for cells and organs to work optimally and for groups of organs to function normally. Groups of organs, which are often called organ systems, that are impacted by body water levels are numerous and include the cardiovascular system, thermoregulatory system, and the central nervous system, amongst others. Alterations in the functioning in any of these systems, both in isolation and combination, can have tremendous impacts on physical functioning and decision-making, which can have profound impacts on people’s lives, from those working desk jobs to more physically demanding professions (e.g., manual laborers), and from weekend warriors to elite athletes.
Although more subtle than the physical performance effects, the negative impacts of hypohydration on cognition, which is defined as the mental processes required to perceive, process, and produce information, are meaningful. Indeed, hypohydration reduces cognitive function, which is fundamental to success in everyday life, including in occupations and completing tasks requiring inter-personal communication and computations. Examples of cognitive processes that are impaired by hypohydration include aspects of decision-making, reaction time, and vigilance. Thus, peak cognitive performance requires good hydration practices. For instance, even small reductions in body water reduce mood and stimulate symptoms of headache, fatigue, and thirst. All these factors have been proposed as distractions causing impairments when performing cognitively demanding tasks. Moreover, greater levels of hypohydration can directly alter brain structure, which can alter cognitive performance.
Collectively, good hydration is vital for ensuring optimal physical functioning!
How do you ensure good hydration? Follow these helpful (and simple) tips!
- Ensure easy access to cool drinkable fluids.
o Water is generally fine, but if exposed to heat or exercising for a long period of time (>2 hours) consider fluids with electrolytes.
o Consider drinking something with flavoring if you do not like the taste of water but be sure that it does not contain too much sugar (e.g., avoid soft drinks).
- Remember to drink early and often – you should drink before you get too thirsty
- Monitor urine volume and color to estimate hydration status – if the need to urinate is infrequent and the urine is dark, drink more.