How much water should I drink when sweating? Fluid intake guidelines.
The average 70kg male body is made up of around 60% water, and around 2-4 litres of this is lost in a sedentary day, through urination, breathing and through the skin, according to research analysed in Thorzt’s new Workplace Hydration White Paper.
Lost fluids must be replaced, and generally accepted broad recommendations are for the consumption of around 2.6 litres, or around 10, 250ml glasses of water each day.
However there are a number of other factors influencing individual fluid intake requirements which may demand far greater fluid consumption, especially for the blue collar worker in hot Australian conditions.
Fluid Loss Influences:
Physical activity, diet, heat acclimatisation and fitness status, metabolic rate, body mass, size and environmental conditions such as temperature, humidity, wind, solar load and the amount and type of clothing worn all contribute to fluid intake requirements.
Furthermore, an air traveller can lose up to 1.5 litres of fluid on a three hour flight, something FIFO workers and mining OHS officers should consider, especially since mining workers are regularly found to be dehydrated at the start of their shift.
Broad fluid intake guidelines for those working in hot and humid conditions have been set at around 250-300ml of fluid every 15-20mins, however the variables outlined will influence that figure.
Staying Hydrated in the Workplace:
While it is important to consume as much fluid during and after a shift as has been lost, intermittently guzzling large amounts of water is not a good way to stay hydrated, and may lead to the dangerous condition of hyponatremia.
Instead it is recommended that broader diet and lifestyle structures are implemented along with hydration and heat stress awareness training for workers. Strategies to facilitate fluid consumption such as programmed drinking and worker monitoring should also be identified.
Alcohol consumption should be avoided or discouraged as it contributes to dehydration by acting as a diuretic and increasing urine output, while sugary drinks and energy drinks should be avoided, with energy drinks being banned on some sites.
Food intake also plays a role with a large amount of our fluid requirements potentially coming from food. Eating well will help hydration efforts while also providing the body with electrolytes, essential amino acids and nutrients, especially important for those who have been sweating heavily.
Milk, soup, juice, fruits and even coffee and tea in smaller doses (less than 180mg each day in caffeine) contribute to daily fluid intake requirements, as does chicken, vegetables and most other solid foods (see “What’s in Your Food”, page 15 of the Thorzt Workplace Hydration White Paper).
However a loss of appetite is commonly associated with physical exertion in hot conditions, further contributing to dehydration. This adds to the importance of having a specifically prepared low-sugar electrolyte solution such as THORZT available for workers, to help them maintain blood sugar and sodium levels along with energy and cognitive function.
For more detailed information on hydration management, see the Thorzt Information Centre.