person Taking on water whilst exercisingIt is no secret that the human body needs to have an adequate supply of fluid to maintain hydration and promote optimal health.

Feelings of thirst begin at less than 1% dehydration, by 3% dry mouth and at only 4% dehydration a 20-30% reduction in work capacity is experienced.  However, knowing the importance of hydration and successfully achieving an optimal level of cellular hydration are two entirely different things.

There are many different factors that can influence hydration, including:

  • Volume of fluid consumed
  • Sugar content of the fluid
  • Electrolyte content of the fluid
  • Alcohol and caffeine content of the fluid
  • Contribution of food

Volume of fluid
The Foods Standards Agency advises an average intake of between 6-8 glasses (1.2 litres) of fluids per day. However, the World health organisation sets fluid intake at double the level for adults to a range between 2.2 to 2.5 litres per day.

Sugar content
Sugar content has a significant impact on the hydrating capacity of a fluid. In general terms if the fluid has a higher sugar solution than the blood stream it has the potential to draw fluids out of the cells and dehydrate them. If the sugar solution is kept lower than the concentration of blood it has the potential to help move fluids into the cells and hydrate them.

Electrolyte content
Electrolytes are most commonly derived from the mineral content of a drink. Minerals such as sodium chloride or magnesium chloride dissolve into solution and can have a significant impact on the movement of fluid in and out of the cells of the body.

Alcohol and caffeine
Both alcoholic and caffeinated beverages have gained a reputation as drinks that dehydrate the body. Up to date research suggests that tea and coffee without added sugar does not increase the level of excretion any higher than the same volume of water would induce.

Contribution of food
The consumption of certain foods will also contribute to the total fluid intake of the body. Fruits and vegetables do contain varying amounts of fluid and often a good balance of minerals. These both aid and contribute to overall hydration.

If you have any thoughts on hydration, why not share them with us in the comments box below.

Ben Pratt
Tutor Manager