The Northern Hemisphere’s unrelenting summer heatwave meant that access to safe drinking water, and the opportunity to take drink breaks to ward off dehydration, became more important, especially for outdoor workers. International research shows that agricultural and construction workers are most likely to experience heat stress. In New Zealand, the popularity of summer sports means our athletes and sportspeople are also at risk.
An “atypical” El Nino summer is predicted, bringing with it hotter and drier conditions. That means those in the northeast of the country are warned to expect hotter and drier conditions, so staying well-hydrated should be a priority. In this article, first published in the Listener of January, 23, 2021, Jennifer Bowden writes of the need for regular water breaks.
Whether you’re older or younger, summer presents the same risk – dehydration, thanks to the escalating heat and less-than-optimal fluid intake. More than half of older adults are either dehydrated or very close to dehydration, studies have shown, and one global study found about 60% of children aren’t meeting water and fluid intake guidelines.
Our body needs water to function correctly. When we lose more fluids than we consume, it places our health at risk. In older adults in particular, dehydration is associated with a high risk of adverse health outcomes and is a significant contributor to morbidity and death. This includes “falls, fractures, heart disease, confusion, delirium, heat stress, constipation, kidney failure, pressure ulcers, poor wound healing, suboptimal rehabilitation outcomes, infections, seizures, drug toxicity and reduced quality of life”, according to a 2015 Cochrane Review.
Sports scientists have led the way in studying the impact of dehydration on sports performance, noting that a 2% loss of body weight through sweat has a significant effect on physical and mental performance. Among elite cricketers, performance declines when they don’t stay well-hydrated with drinks at the sideline. One study of top Sri Lankan cricketers found that 85% of the fielders and bowlers were unable to maintain levels of speed and accuracy when dehydrated. Fielders suffered a sizeable reduction in throwing speed and accuracy for overarm and sidearm throws – sidearm-throw accuracy dropped by 22%. Bowlers’ speeds dropped and their accuracy decreased by 20%. Batsmen were mildly affected, running 2% slower when completing three runs, which could be the difference between a run-out and a run.
But even those sitting at home watching cricket on television can be significantly affected by dehydration. Recent studies found that even a relatively small loss of 0.6% of body fluid affects mood and memory. Children are particularly susceptible to dehydration because they often rely on adults to supply them with drinks. In one study, when 9- to 11-year-old children drank more water for four days, they had faster reaction times on a task-switching test and an increased ability to multitask.
Older adults are at greater risk of dehydration because their “thirst response”, which guides their fluid intake, declines with age. In addition, their ability to retain salt and fluid reduces as kidney function declines. On top of that, many medications can also increase dehydration risk.
Unfortunately, there are no simple tests to determine dehydration in older adults – even possible symptoms such as loss of elasticity of skin or a dry mouth are unreliable. Instead, researchers have found that merely asking an older adult whether they have been drinking fluids between meals or are feeling fatigued is likely to more accurately gauge their hydration status.
Having fresh water handy is a significant first step in ensuring children and older adults stay hydrated. When water dispensers were installed in New York school cafeterias, the students drank three times as much water. Similarly, US Army employees more than doubled their intake when a water jug was placed on their dining table instead of 6 metres away.
Parents, too, are important role models when it comes to water consumption. And it’s not so much what they say but what they do that has the most significant impact. Hence, parents who make a habit of regularly drinking water and encouraging water consumption over other drinks are more likely to instil similar habits in their children.
It’s a good idea to keep a water bottle handy in the car, on the bus or at your desk – make water so convenient that it’s easy to say yes to more. Another tip is to keep a jug of chilled water in the fridge and place it on the dining table at breakfast, lunch and dinner – and remember to drink between meals. The goal is to drink regularly throughout the day, not just one big glass with medications in the morning.
This article was first published in the January 23, 2021 edition of the New Zealand Listener.