Sports Drinks and how to make your own

With lockdown easing and the return of Grassroot sports, it is very important to keep hydrated. sports performance can be affected by dehydration, so it is important to be well hydrated…before, during and after activity.

Drinks can contain various amounts of carbohydrate & electrolytes (salts) that assist with rehydration or energy replacement. Choose a drink depending on whether you need to replace fluids or energy/carbohydrate (or both):

Water – will replace fluid losses but not provide energy – suitable for low intensity or short duration exercise (less than 45 minutes) – for longer activities (more than one hour) add a little sugar & salt to enhance absorption & fluid retention.

Hypotonic drinks – these contain low levels of carbohydrate (less than 3g/100ml) & some salt – they are absorbed into the body more quickly than water – they provide fluid but not much energy use these drinks to replace fluid quickly & when energy is not really required (if training lasts less than one hour & is low intensity).

Isotonic drinks – these contain carbohydrate (4-8g/100ml) – they are absorbed into the body as fast or faster than plain water – they provide fluid & some carbohydrate to fuel the muscles – these are the most effective drinks to use for rehydration during training & competition use these to replace fluids & for some energy (if training for more than one hour) – drink before, during & after exercise.

Hypertonic drinks – these have a higher carbohydrate content (more than 10g/100ml), including pure fruit juice, many canned drinks & energy drinks – they are absorbed more slowly than plain water – they replace lost energy rather than fluids & are therefore not an effective way to rehydrate use these when energy replacement is important (eg: when you are unable to get enough energy from food & need to top up your daily carbohydrate intake),

Stimulant drinks usually have a high carbohydrate content (which does not help with rehydration) & other additives (eg: caffeine, taurine), most of which have no beneficial effect on performance. These drinks should be avoided during sport.

Most people need 1.5-2L of fluid per day plus what is lost during exercise. Fluid includes all drinks, plus fluid in meals (like milk on cereal, or soup). Ideally, start activity fully hydrated by drinking about 500ml water, or suitable sports drink, about 2 hours before activity, plus another 150-350ml in the 10 minutes before starting activity. During activity drink small amounts frequently (150-200ml every 15-20 minutes). After activity, try to replace fluid losses within 2 hours, especially if training more than once a day. Do not wait until you feel thirsty (by then you will already be dehydrated).

Young athletes bodies are less able to cope with the stresses of activity because their bodies are not very efficient when coping with the heat activity generates, & the temperature & humidity of some pools do not help the situation. As a result young athletes are at greater risk of dehydration, as well as being more sensitive to its effects. Young athletes do not realise how much fluid they are losing during activity & they are not very good at replacing fluids voluntarily – therefore they should be reminded to drink during training (every 15-20 minutes). Children should be allowed to drink until their thirst is satisfied, then encouraged to drink some more (because their thirst mechanism is poorly developed). If young athletes are particularly irritable at the end of a training session they should be monitored to assess how much fluid they are habitually drinking. Water is an acceptable drink, but it may be necessary to provide a flavoured drink that is more appealing & provides some energy.

Fluid losses can be monitored by checking body weight before & after activity (1kg lost body weight = 1L fluid lost from the body). Dehydration can be checked by using a pee chart (right).

 

Generally, if training involves less than an hour of activity it is not necessary to refuel during activity. Good food & regular drinks before training will provide adequate energy & hydration for activity, and then good food & drink choices after activity will refuel & rehydrate the body.

Recipes for home-made sports drinks

Try different drinks during training to find one that you like. Drinks might taste different during & after exercise, so don’t decide on a drink when you are not exercising. Choose a drink that best matches your needs (fluid or energy). Salt in drinks enhances absorption & retention of fluid in the body.

 

Hypotonic drink                                   Hypotonic drink

100ml fruit squash                               250ml fruit juice

900ml water                                        750ml water

1/5th teaspoon (1g) salt                        1/5th teaspoon (1g) salt

 

Isotonic drink

50-70g glucose or sugar

1L water or sugar-free squash

1/5th teaspoon (1g) salt

Dissolve the glucose or sugar & salt in 100ml warm water before adding them to the remaining 900ml cold water or sugar-free squash

 

Isotonic drink                                      Isotonic drink

500ml unsweetened fruit juice             150ml high juice squash

500ml water                                        850ml water

1/5th teaspoon (1g) salt                        1/5th teaspoon (1g) salt

 

Hypertonic drink

400ml squash

1L water

1/5th teaspoon (1g) salt

 

References:

Sport Nutrition 3rd Edition 2019 Author: Asker Jeukendrup Michael Gleeson

Food for Sport: Eat Well, Perform Better Griffin, Jane (2001) Food for sport, Crowood Press

https://www.bda.uk.com/ 

www.sportsdietitians.com.au;