Water and You
Water is vital for our survival, with the human body being made up of 75% water as infants to 55% as elderly adults. Water plays an important role in regulating our body’s temperature, in delivering nutrients — such as life-giving oxygen, in flushing waste, shock absorption, digestion and the list goes on. With our busy working schedules and numerous extracurriculars demanding our time, it can be difficult to meet our recommended daily water intake.
Recommended Water Intake
Often, we may try to look for a “one-size fits all” model for our water consumption. However, research suggests it may be more complicated than simply the “8 glasses per day” rule. The reason is that many factors contribute to how much water we should be drinking per day. Factors such as our physical activity, the climate we live in, the type of job we work (eg. standing vs. sitting), or our diet can all play a role in determining the amount of water we should consume on a daily basis. Due to the large variability in water needs among individuals, basing our water intake on metabolism alone cannot assure that everyone is keeping adequately hydrated.
A safe rule of thumb for keeping hydrated includes:
- Trusting your thirst
Receptors throughout your body are extremely sensitive and precise in sensing changes in your body’s water content. Deficits to your total body water by only a few hundred milliliters will cause the thirst mechanisms in your brain to ramp up, activating your thirst.
2. Increasing water intake when physically active or in hot or dry climates
Sweating, which causes evaporative water loss, regulates the body’s temperature to prevent overheating. Inadequate water intake following vigorous exercise or prolonged exposure to heat can result in dehydration and electrolyte imbalances. For example, water loss from sweating can range anywhere from 0.3L/hr in sedentary individuals, to 2.0L/hr in those involved in high intensity activities. That means adults under normal conditions require around 2.5 to 3 liters per day, with up to 6L/day in extreme conditions of heat or vigorous exercise. It is important to note that you should only drink enough water to compensate the fluid lost in your activities, and to stop drinking when you no longer feel thirsty.
Children and the elderly differ in how their bodies respond to heat exposure and how easily they can regulate their own temperature, compared to healthy adults. Also, children have a larger surface area to body mass ratio. Coupled with a lower rate of sweating, an inability to communicate their needs and slower ability to acclimatize to hot temperatures, this can make them especially susceptible to overheating.
Health Risks Associated with Dehydration
Our bodies keep a strict regulation of water levels to ensure our organ systems are functioning properly. Sudden changes in our body’s water balance are rapidly sensed and warning signs can help notify us if we are dehydrated. If these warnings are unanswered, more serious health concerns can result, as our body’s try and cope with the lack of water. Being mindful of the warning signs of dehydration and the potential health complications can give you the tools to keep you healthy and hydrated.
Warning Signs of Mild-Moderate Dehydration in Adults:
- Increased thirst
- Dry mouth
- Urinating less frequently than usual
- Dark-coloured urine
- Dry skin
- Dizziness or fainting
- Increased fatigue
Signs of Dehydration in Infants and Young Children:
- No tears when crying
- Lack of wet diaper for more than 3 hours
- Dry mouth and tongue
- Increased drowsiness
If dehydration persists, more serious health complications can arise:
- Reduced motivation
- Reduced concentration or alertness
- Reduced short-term memory (problems recalling information)
- Impaired performance
Tips to Keep You Hydrated
- Set reminders
If you know you are going to the gym or will be busy running errands, it is best to come prepared. Setting reminders on your phone to give you additional prompts to drink water can help ensure you stay hydrated and active throughout your day. You may also consider keeping your water bottle in a visible area, such as bedside for when you first wake-up or on your desk at work — this way you won’t forget to grab a sip on the go.
2. Freshen up the flavor
Tired of drinking plain old water? Try adding fresh slices of lemons, limes or cucumbers to add refreshing flavor to your drink. Mint leaves and berries can also add a delicious and tangy sweetness.
3. Drink more when working out
Try to drink water before, during and after exercise to maintain your water balance. You may also consider drinks such as coconut water that contains natural amounts of magnesium and potassium to replenish lost electrolytes from sweating.
Keeping yourself hydrated throughout the day can greatly improve your wellness, helping you stay active, alert and energized.
Nicolaidis S. Physiology of thirst. In: Arnaud MJ, editor. Hydration Throughout Life. Montrouge: John Libbey Eurotext; 1998. p. 247.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2908954/ (summary of recommendations for water intake)
Benefits of Water:
https://www.sciencedirect.com/science/article/pii/S0195666312004321 (cognitive performance)
https://medlineplus.gov/dehydration.html (warning signs of dehydration)
https://www.ncbi.nlm.nih.gov/pubmed/3355239 (impaired cognition with mild dehydration)