We all know that if we don’t drink enough fluids, we will get dehydrated, especially when it’s hot. But do we know what impact this really has on our performance, both physically and psychologically?
As the weather gets warmer, we need to take precautions to prevent any heat-related illnesses, and to make sure we are at our best every day.
We see plenty of advice in the media telling us to drink 2 litres of water a day (or 8 glasses), and with good reason! It has been found that the average person only drinks 2.5 glasses of water a day! If you drank a glass of water every 2 hrs, then you’d easily hit the 2 litre quota.
Try to avoid feeling thirsty, as this is the first sign of dehydration. Remember to increase this when you’re exercising as you’ll dehydrate more and quicker. Try to drink a bottle of water 2 hours before you exercise so you start hydrated, and then drink every 20 minutes to stay hydrated. This requirement also increases when the temperature does. To properly re-hydrate, you should match your fluid loss when replacing it.
A 2% drop in hydration levels can decrease performance by up to 15%. This can be physical or cognitive performance, and this is exacerbated in the heat. Ideally you should have around 50% total body water to be hydrated.
The impact on cognitive ability can include short-term memory and long-term memory retrieval. It can also affect your mood and when you’re dehydrated, you probably have a headache, so you’re not going to feel your best!
However, when you’re hydrated, you’ll see plenty of positives! Being hydrated can stave off fatigue, help to flush toxins out of your body, improve your skin and support your cardiovascular health. When you’re dehydrated, your heart has to work harder to get the reduced blood plasma around your body to supply oxygen – your heart rate will increase and you’ll feel more tired.
Water will also help keep you cool as it gets hotter. When you’re hydrated, your blood vessels close to the skin surface can widen, and blood flow will increase, meaning more heat is dissipated. This is key to maintaining a healthy core temperature and again, avoiding heat related illnesses.
Of course, we can take on fluids from sources other than water. Juices and milk all count, but we must be careful of high sugar and caffeine loaded drinks. Large doses of caffeine increase blood flow to the kidneys, which inhibits absorption of sodium which is a key electrolyte. When we are dehydrated, these levels of electrolytes will be lower, and we need to be replacing fluids as well as electrolytes, especially if we’re exercising and thus sweating! It has been found that sodium content needs to be high enough to replenish levels, otherwise urine output will increase and you’ll dehydrate more! Sugars contribute to our calorie intake, and when not burned during day-to-day movements and exercise, will be stored as fat.
Alcohol hasn’t been found conclusively to increase dehydration, but why do we wake up with a hangover?! This is because alcohol increases urination as it has a diuretic effect, so we release more fluids, which makes us dehydrated. Funnily enough, alcohol is not an ideal rehydration drink, especially when exercising. It impairs muscle recovery and performance. Sitting in the sun and enjoying a Pimms is all part of summer, but the effect of the heat will mean we’re more dehydrated anyway.
Being aware of your fluid intake levels and hydration will ensure your body performs at it’s best. Check your urine. Aim for very light ‘straw’ colour to clear and keep a bottle of water on you most of the time to get you in the habit of drinking plenty.
If you’d like to raise awareness of hydration in your organisation, discover how we can assist you with our corporate health and wellbeing programmes. Contact us to find out more, we’d be delighted to help you.