Guide to Fluid and Fuel Replacement for Training or Sport Posted on 9 Aug 20:09 , 0 comments

There is no one fluid replacement plan that will meet every sports persons needs. An effective strategy that you can use to monitor fluid loss is to measure your body weight before and after exercise.  That way you can get a good indication of how much fluid has been lost. One kilogram of body weight equals one litre of fluid so get into the habit of weighing yourself before and after exercise sessions so you can start to plan how much water you’ll need for similar sessions in the future.  

Aim to replace one and a half times the amount of fluid lost as soon as possible after finishing the session, using a sports drink if applicable.  For example, if you weigh 1 kilo less after the exercise session, then you need to replace the lost fluid with1.5 litres of fluids.

Water or Sports Drinks?

Sports drinks have been shown to enhance sporting performance in situations where training sessions are of high intensity or are of one hour or longer duration. Sports drinks have been specifically designed for these situations and not only are an excellent way to keep you hydrated, but they are also a convenient source of fuel during exercise.

A suitable sports drink should provide 6-8g of carbohydrate per 100ml, so check the label and ensure you prepare it to the correct dilution, if making it from a powder.

Tips to keep you Hydrated during exercise:
·      Start hydrated
·      Consume 200-600ml fluid before you exercise
·      Choose a sports drink you have tried before and which you like the taste of and that you know doesn’t cause any  gastric upsets
·      Carry sufficient water – it’s better to come back with fluids to spare, rather than in a dehydrated state!
·      Aim to drink 150-200ml every 15-20 minutes during the session
·      Use every opportunity to drink
·      Remember – even when it’s cold you can still get dehydrated, so drink frequently

During Exercise:
For exercise sessions of an hour or less, water will be sufficient, As the duration and/or intensity of the exercise increases longer than an hour, the need for carbohydrates (muscle and brain fuel) increases, along with electrolytes to replace sodium and potassium lost through sweat.  

For long duration exercise, consuming 30-75g of carbohydrate per hour is recommended.  Performance benefits begin at 30g per hour, however 50-75g per hour may be optimal to meet fuel needs during exercise after muscle glycogen depletion has occurred.  Personal tolerance and carbohydrate requirements will vary.

Carbohydrate replacement can be achieved through sports drinks and/or gel type products.  If you are using gels, remember to use plenty of water with them to avoid any gastric upsets.  If you know you are going to be training for longer than 60 minutes, start consuming carbohydrate replacement products after around 45 minutes and spread the rest of the products evenly out over the rest of the time, at around 45 minute intervals.  Practice with the timing to see what works best for you, for high intensity exercise, you may need to replace carbohydrates every 30 minutes, so practice is vital.  Don’t wait until you start to feel fatigued before you begin using the carbohydrate replacement products.

Caffeine containing sports replacement products help spare your own carbohydrate supply and encourage your body to use stored body fat for fuel and they can also help keep you mentally ‘on to it’ and give you a bit of an edge.  As with any sports replacement product, practice with them first before using during an event.

Post Exercise:
Immediately after exercise, fluids, electrolytes and carbohydrates have to be replaced to assist recovery.  Water alone is not sufficient and will not be as rapidly absorbed as sports drinks at the correct dilution.  Aim to consume 1g of carbohydrate per kilo of body weight immediately after exercise and again every two hours afterwards.

This is a good time to add in some protein as well, to assist with muscle repair and recovery.  A protein shake made with whey powder, milk and fruit will be easily absorbed and used by the body and provide protein and carbohydrate.