By Coach Brendon

A fluid strategy is important not only for performance but also for safety and enjoyment. Without a good fluid plan you won't be able to make the most of your training. A loss of only 2% of your body weight will decrease your performance by 10%. If you want to achieve your personal goals in the marathon then having a good fluid strategy (that you have practiced in training) is important.

How much fluid do you need?

Everyone is different, if you live in a cool climate and are racing in warmer ones, then not doubt you will need to drink more than usual. If you practice drinking good amounts of fluids in training, you will be able to drink more in events also. Your body will adapt to what you show it. Below is a general guide to give you a ball park figure.

Fluid Intake Per Hour (Note: These are good starting points only - you still need try out your fluids as everyone is different)

Set up a system for drinking

Most of the modern heart rate monitors and many of the good sports watches have timers that can be set to beep every 15 minutes. Your stomach is like a balloon - the more fluid inside, the more pressure forcing fluid into your gut where fluid is absorbed. You need to drink 300-400mls at the start to get your fluids into your body once you have done that you can top up every 15 minutes with 150-250mls. You need to practice this in training.

Don't forget to monitor how you feel

If you feel nauseous then you may have consumed fluids that are too strong for you, drink some water to help dilute down what is in your stomach.

If you feel bloated, your stomach is full. In this situation reduce your drinking as you are consuming more than your body can process. This can also be caused by drinking strong drinks that sit in your stomach.

How do you carry your drinks?

There are a lot of good products out there to ensure that you can carry enough fluid. A Camelback drink system is great. The standard unit can hold up to 2.2L of fluid. With the insulation the drink can be kept reasonably cool and freezing it the night before a really hot run means you will be able to drink nice cold fluid. This product is really great for bush walks and runs as you don't need your hands to drink and the volume they hold makes them great for long training sessions.

There are also a number of great running belts that not only hold water bottles but can also hold your cell phone and your MP3 player (good for the mental aspect of long runs).

Drink bottles with the wide screw top neck are great. It is easier to mix a sports drink in these bottles without getting the powder on the outside of the bottle, thereby avoiding the 'sticky hands' syndrome. If you are going to run over 60 minutes it will also pay to have more than one drink bottle and to use larger drink bottles. Small bottles hold 500mls, medium size bottles will hold 750mls and you can get large bottles that hold 900mls. I have two 900ml bottles, on a hot day that's enough fluid for 3 hours when training or 2 ½ hours when racing. You can hide these along your training course or leave at your car and return 1/2 way through your run to pick up.

What about sports drinks?

The general rule is less than one hour and water is fine but once the length of the session starts to increase you will need to take in energy and electrolytes. Sports drinks are designed to optimise fluid and energy intake. There now is enough research to say that sports drinks improve performance in events as short as one hour, so once you reach this point it is a good idea to start to either eat some food or use a sports drink. Good hydration in training means you will recover faster and this can only help you in your preparation for the marathon. There is now some good evidence that sports drinks improve performance in endurance events. They are also a good way of getting some of the energy into your body plus they are absorbed faster than water.

To use Coke or not to use Coke

Coke seems to be a really good product for enhancing performance. It's got water, sugar and caffeine. But it's a bit strong so you need to dilute it to at least two-thirds strength. The big draw back with coke is that once you start using Coke you need to keep using it or you will hit the wall big time. You must practice with coke in training and NEVER EVER drink fizzy coke. I recommend Coke only to experienced Marathoners and then only in the latter 1/3 of the race.

Practice bottle pick ups. If you are racing and are planning on getting a drink pickup during the event it makes sense to practice this in training. A lot of smaller events leading into the marathon have drink stations and you can try picking up cups of water during these events.

So there you have it go out and drink your way through your Marathon!

Check out 'A Guide to Fluid Intake for Cycling' here.

If you'd like help with a nutrition plan for your racing season, visit our Endurance Nutrition page here.

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