Keeping Hydrated

Keeping Hydrated

On Hot Days

On very hot days, your body heats up faster than when the weather is cooler. To remove this heat and maintain an even temperature, the body automatically produces sweat. Sweat evaporating from the skin helps regulate body temperature and keep it around 37°C. If you don’t have enough water in your body to sweat freely, it is harder to keep cool and comfortable. The increased amount of sweat produced also contributes to an increase loss of fluid, and an increased need to replace this fluid [1].

    • Double your usual meal time fluid intake, so make it 2 glasses of fluid instead of one.
    • Hot days can also bring warm nights, so make up for the fluid you’ve lost overnight by having an extra glass of water before breakfast.
    • Aim for 1 glass of fluid every waking hour.
    • Try to vary the fluids you drink so you don’t get bored. For kids, try fruit juice diluted with water and add novelty shaped ice cubes or freeze fruit juice as a healthy ice block alternative. For adults, try iced tea with mint and ice cubes, fruit juice mixed with soda water, diet soft drinks or water with a squeeze of lime or lemon.
    • Carry a water bottle when you go out. Even a short drive in the car can lead to excess sweating on hot days.
    • Enjoy ice blocks as an alternative source of fluid for variety. Try making your own by freezing cordial, fruit juice or other non-carbonated beverages.

While Traveling

Overheating or dehydration when travelling is not only uncomfortable, it can also make you feel too tired to enjoy your trip. More importantly, it can make it difficult to concentrate and therefore arrive at your destination safely.

When you have the windows open or the air conditioning on in the car, the cool feeling you experience is the result of a continuous loss of fluid as sweat evaporates from the skin. The same goes for the cooling system working inside a plane. This lost fluid must be replaced to ensure you stay well hydrated throughout the journey, especially on long haul flights. If you are driving or flying, have regular breaks when you can top up on fluids, stretch and relax. Just like stopping to put more fuel into your car, you need to add more fluids to your body to keep it going.

Feelings of thirst are generally a good indicator of when your body needs more water, so it is important to be aware of the needs of those travelling with you, especially when travelling with children. Children can become dehydrated faster than adults, so make sure they have easy access to fluids throughout the trip as well.

Aim to drink at least 250ml of fluids per hour while travelling (the equivalent of around one large bottle of water every three hours).

  • Freeze spring water, cordial, or juice the night before your trip. This will melt as you drive, providing a continuous supply of cold drinks.
  • Carry a small esky with ice, so drinks will stay cool during your drive.
  • Take drinks in bottles you can easily pick up and squeeze into your mouth while travelling. Make sure they close easily to prevent spillage.
  • Fill a reusable bottle with weak iced tea, sugar and lemon for a refreshing change.
  • Never by shy to ask the flight attendants for water to drink or a beverage every hour during your flight.

At Work

Whether your workplace is air-conditioned or more open to the fluctuations in daily temperatures, your body loses a large amount of fluid throughout the day as part of its “keeping cool” process. Between 1 and 3 litres of fluid is lost from the body each day, and even more when exercising or sweating heavily.

In air-conditioning, the circulating air causes water to continually evaporate from the surface of your skin, which is what gives you a cooling effect. In a warm workplace that doesn’t have freely circulating air, your body is more likely to lose fluids through sweat. This perspiration gradually evaporates enabling your body temperature to remain even.

Your body needs fluids to work efficiently in either environment, so make sure you stay well hydrated throughout the day. Having adequate fluid on board will assist you to remain alert and maintain concentration levels during a busy working day.

While feelings of thirst are usually a good way to gauge your fluid needs, requirements are different for men and women and can vary significantly in varying work environments. Try to drink at least 1.5 litres of fluids during working hours, and people who work in hotter environments or perform physical tasks will need more [3].

  • If you find you often forget to drink fluids when you are busy at work, try scheduling a drink reminder every hour into your daily planner.
  • If you have easy access to water in the office, aim to have around least six glasses (1.5 litres) a day.
  • Put bottles of mineral and spring water in the staff fridge at night so you have a ready supply of refreshing fluids the following day.
  • If you can only drink during work breaks, have 1-2 drinks every break. Fluids such as plain water or lightly flavoured waters are good choices to make up the majority of your fluid intake. Add variety with the occasional juice, cordial, sports drinks or soft drink.
  • If you dislike the taste of water but are concerned about your weight, add low joule cordial for additional flavour without additional kilojoules. Low joule or diet soft drinks are also good choices along with low joule flavoured waters. There are also low joule iced teas which are a very refreshing alternative.
  • Find different fluids to enjoy with meal breaks to add variety, such as flavoured iced tea or mineral water with added fruit pieces for a light flavour and plenty of colour.
  • Have a drink as soon as you get home from work, such as water with a hint of squeezed lemon or some mint leaves.

At Sport or Play

More than 60% of Australians participate in sports and physical activities, although most people play for enjoyment, putting in your best performance as part of the team is still important. Maintaining adequate levels of hydration is essential for optimal sporting performance, so whether you are training to represent Australia at the next Olympics or simply out walking with friends, it is always important to keep your fluid intake up. Australia’s best athletes agree that staying well hydrated during and after training or competing is vital for successful performance. Low body fluid levels mean increased chance of injury, stress and decreased performance levels [5].

During exercise, the body maintains an optimal temperature by sweating – so it is important to start exercise being fully hydrated, sip fluids regularly during training, and then continue to drink fluids after the activity to replace lost fluid. When you exercise heavily, you lose important electrolytes (salts) in your sweat, which also need to be replaced.

Thirst may not be a reliable indicator of how much fluid you need while exercising, so make sure you have a hydration plan that suits your needs. If you’re really serious about your sport or are training for an endurance event, seek the advice of an accredited sports dietitian.

As a general guide, Sports Medicine Australia recommends the following fluid replacement routine for sports [6]:

  • Drink 500mL half an hour to one hour before exercise
  • Drinks 200mL every 20 minutes during exercise
  • Drink 500mL to 1 litre after exercise


1. Shirreffs, S.M., et al., The effects of fluid restriction on hydration status and subjective feelings in man. Br J Nutr, 2004. 91(6): p. 951-8.

2. Sports Dietitians Australia, Nutrition and Physical Activity for Australian Children. Medical Journal of Australia, 2000. 173 (Suppl 7): p. S1-14.

3. Sawka, M.N., S.N. Cheuvront, and R. Carter, 3rd, Human water needs. Nutr Rev, 2005. 63(6 Pt 2): p. S30-9.

4. Sports Medicine Australia, Drink Up Beat the Heat Factsheet, Smartplay: ACT.
5. Australia, S.D., Nutrition and Physical Activity for Australian Children. Medical Journal of Australia, 2000. 173 (Suppl7): p. S1-14.
6. Sports Medicine Australia, Safety guidelines for children in sport and recreation. 1997, Canberra.