Health: Staying hydrated

Performance / 24 August 2011

As the weather heats up, staying cool and hydrated in the office gets harder. Alison Hjul explains why water and fresh air are essential if you want your productivity levels to stay as high as the temperature

Few things are guaranteed to lift our spirits more than waking up to a warm and sunny morning. However, we’re likely to feel seriously deflated – not to mention irritable and sore headed – after a day in a hot and stuffy office.

Dehydration is a major factor in our summertime suffering. This results when we fail to replace the fluid lost through sweating, breathing and urinating. Our bodies are around 70% water and it’s essential for a number of vital functions, such as transporting nutrients and oxygen through the blood (which is 95% water). Our brains are also largely water (around 85%), which is why dehydration affects concentration – a survey of office workers by drinks company Juice Doctor found that being just two per cent dehydrated can reduce concentration levels by up to 20%. With 84% of respondents admitting that thirst impacts on their work, employers need to wise up to the negative effect of dehydration on productivity.

They should be particularly vigilant that people in at-risk groups remain well hydrated, warns Eugene Farrell, business manager at wellbeing programmes provider AXA ICAS: “Water is involved in the maintenance of blood pressure and dehydration can put staff with cardiac conditions at risk from raised blood pressure. Pregnant women are also at significant risk from dehydration.”

No sweat

The risk for everyone is greater in hot weather because we sweat more, which is compounded if our job involves physical exertion. Air conditioning doesn’t help much either since it can be dehydrating. Dehydration is, however, entirely preventable. “Employees need to know what symptoms to look out for – such as headaches, exhaustion and muscle cramps,” says Farrell.

Employers can help by consulting staff about any problems with their working environment, such as equipment causing a heat problem. They should also educate them about the importance of good hydration through channels such as intranets, posters, desk drops and manager briefings.

Employees need to know what symptoms to look out for – such as headaches, exhaustion and muscle cramps.

Eugene Farrell, business manager, AXA ICAS

“Employees need to understand that when they’re thirsty, it’s too late and they’re already dehydrated,” says Farrell.

Urine colour is the best indicator of hydration levels. It should be a pale straw colour; dark yellow means you need to drink more. This is because kidneys excrete excess water as urine: if we haven’t drunk enough, water gets retained for bodily functions and our urine is more concentrated.

Despite such a high volume of water in our bodies, the average man loses around 2.5 litres a day. The Food Standards Agency recommends that, to replace this, we need to drink 1.2 litres (6-8 glasses) a day (the rest coming from food and metabolic activity). Yet many of us fail to do so: two thirds of respondents to the Juice Doctor survey drank no water or only one or two glasses a day. It’s also best to drink small amounts at regular intervals, to ensure a steady intake of fluid.

But more isn’t necessarily better – it is possible to drink too much and, in rare cases, this can result in hyponatraemia (low blood sodium). Symptoms include headaches, confusion, muscle spasms, nausea and vomiting, and it can cause potentially fatal swelling in the brain.

Employers should also be aware that they have a legal obligation to provide clean drinking water in their workplace. This has to be easily accessible by all employees, advises the Health and Safety Executive, and cups or drinking fountains must be supplied.

Experts disagree, however, on how much of our fluid intake should come from plain water, with many believing it’s sufficient to drink any liquids. It has long been thought that caffeine from coffee, tea or cola was dehydrating since it’s a diuretic. While more recent research has concluded that caffeine is only a mild diuretic, too much can trigger other symptoms, such as sleeplessness and anxiety, so it’s best to limit your intake and drink mostly water.

Fragrant water and isotonic drinks can also be good alternatives to plain water, says Farrell, who suggests employers with vending machines replace carbonated drinks with these. Isotonic drinks are popular for replacing lost fluids and essential nutrients during exercise, but can also benefit those at risk from dehydration in the workplace, he says.