Hydration matters
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What it takes to stay hydrated - if you're thirsty, it's too late!
Sports dietician Lisa Sutherland explains why planning ahead is vital for keeping up your fluids.
We all know that feeling of struggling up the final hill and not being too sure if you're going to make it. Did you ever consider that the fluids you drink in the hours before and during the ride could make a difference?
Hydration is important for energy levels and performance. Hydrating your body should start first thing in the morning, with a couple of cups of fluid with breakfast. The ideal fluid is water. Drink it regularly throughout the day - and always take water with you on your bike.
How much fluid do I need?
Most active adults require about 2-2.25 litres of fluid per day as a base intake, with extra intake during exercise or in warmer weather.
If you are preparing for an event, you can work out how much fluid you need by measuring your fluid losses during training.
- Measure the difference between your body weight before and after training. One kilogram lost in weight equals 1 litre of fluid.
- Add the amount of fluid you consumed during training to the amount you lost in weight. For example, if you lost 1kg during training and had drunk 2 litres of water, in future sessions you should consume 3 litres of water to maintain hydration.
Signs of dehydration
Dehydration is a common cause of fatigue on longer rides. If you're out on the road for hours at a time, you will probably lose a lot of fluid through sweat - about 500 to 1500ml per hour.
Don't wait to drink until you feel thirsty, as you will already be dehydrated by that stage. Dehydration leads to impaired concentration and co-ordination, increased perceived level of exertion, increased body temperature, muscle cramps, fatigue, nausea/stomach upset and decreased temperature control. Without a conscious effort to drink before and during exercise, dehydration can occur quite quickly.
Urine colour is an excellent indicator of hydration. Clear or pale urine indicates a good level of hydration. (This test is not valid if you take vitamin supplements that cause urine to be darker in colour.)
Staying hydrated on longer rides
The golden rule for hydration on longer rides is to be organised. Always carry a large bottle or two with you on your bike to ensure that a supply of fluid is available.
- Be well hydrated before you begin exercise. A large drink of 300-400ml before you start is ideal.
- Start drinking early on in your ride - don't wait till you're thirsty.
- Keep drinking. Aim to consume 500-750 ml of fluid per hour of exercise.
- After the ride, aim to replace 150% of the fluid lost through exercise. Start drinking as soon as you get off the bike.
What to drink?
Water
The ideal fluid to consume in cooler weather is water. Dehydration can actually be more common in cooler weather, as the urge to drink is less, and you may forget or not feel like drinking.
Cordial
If you find it difficult to drink a lot of water, sweetened drinks such as cordial may help you keep on top of fluid intake, however be careful of sugar intake if you are trying to lose body fat.
Sports drinks
These are of greatest benefit in hot, humid conditions where perspiration rates are high. Sports drinks are formulated to maximise fluid absorption and provide a source of carbohydrates and electrolytes which may be lost in sweat. The sodium in sports drinks enhances fluid absorption. However, sports drinks do contain kilojoules, so don't overdo it.
No-nos
Avoid too many caffeinated drinks such as cola, coffee and 'energy' drinks. The fluid in them is not as well absorbed.
Lisa Sutherland is a sports dietitian and fitness consultant who works for the Hawthorn Football Club and the Victorian Institute of Sport. Visit her website at www.lisasutherland.com.