Water needs on a bushwalk – how much is enough?

We all know that water is critical for life. Staying well hydrated means you will be more alert, have more energy and importantly, have more fun. Our bodies are mostly water, and a loss as small as two per cent may have serious effects on your performance. When bushwalking, we lose most of our water through sweat; sweating is important as it stops our bodies from overheating.

Under typical spring weather conditions, we will lose up about 0.5L of water for every hour of bushwalking. So a typical four hour spring day walk means you need to replace 2L. However, as we are now in mid summer and the weather is hotter and more humid, our water needs can quickly increase to 0.75L or even 1L of water for every hour of walking. So as a general rule, plan to replace half a litre per hour, but if it is hot or humid, carry more.

Plan to replace that water by eating healthy, moist food (think fresh fruits) and by drinking water. You can drink sports drinks if you like, but unless you are doing a very hard workout, they are not normally needed.

It is best to start the walk well hydrated, start drinking a bit extra the day before the walk. During the walk, enjoy a drink whenever you stop. I find it helpful to carry a few old 600ml soft drink bottles filled with water. They are cheap and give you a sense of how much you are drinking. Carrying a few bottles also means that if one breaks or you lose it, there is a backup.

On some walks you may be able to collect water along the way. If you are drinking from creeks, treat the water first. There are filters, chemicals, UV lamps and other great methods of making water safe to drink. For most day walks you can carry enough water in your pack and on some walks you can fill up at taps along the way.

The best way to conserve water is to relax, walk in the cool of the day, rest in the shade and wear loose fitting clothing. If the forecast is particularly hot, it is a good reason to delay your walk. I tend to look at fire danger ratings, I don’t walk in bushfire prone areas on days of Total Fire Ban for safety’s sake. If you need to drink over 0.75L of water an hour, then you are probably pushing your body too hard, cool your body down by resting.

You can learn more about water needs and other bushwalking skills by visiting http://www.bushwalking101.org/water/

Enjoy your bushwalk, eat and drink well. Avoid hot days and have fun.
Happy walking

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