Drinking regularly during exercise can:
- Prevent decline in concentration and skill level
- Improve perceived exertion
- Prevent excessive elevations in heart rate and body temperature
- Improve performance
Every athlete and coach should make fluid replacement a key priority during training and competition.
The type, temperature and taste of the fluid consumed during exercise can have an impact on the athletes hydration status due to the effect on the volume of fluid ingested and absorbed. Research shows that fluid intake is enhanced when beverages are cool (~15 °C), flavoured, contain sodium (salt) and are composed of a combination of glucose, sucrose and glucose polymers. It is important that the sports drinks contain 6-8% carbohydrate concentration to enhance performance, any higher may result in gastrointestinal upsets.
Sport drinks are an ideal choice during exercise that lasts longer than 60 minutes and a great deal of science has gone into developing the carbohydrate, sodium and flavour profile of sports drinks so that they enhance performance and encourage fluid intake during exercise. Food standards in Australia place restrictions on the formulation of sports drinks. As a result, sports drinks sold in Australia are very similar in composition. Choose sports drinks that have 4-8% carbohydrate, 10-20 mmol/L sodium, are affordable, come in a convenient package and taste good.
Consumption of fluids should begin early in an exercise session as it takes 10 - 20 minutes for ingested fluids to reach the bloodstream. A general fluid replacement plan is difficult to prescribe as each athlete is different
Fortunately, the Australian Institute of Sports have devised an easy method to estimate individual fluid requirements:
- Weigh before and after exercise session.
- Each kilogram (kg) of weight lost is equivalent to approximately one litre (L) of fluid.
- Add on the weight of any fluid or food consumed during the exercise session
- The total will provide an estimate of total fluid loss for the session.
Once an athlete's individual sweat losses are known, a plan can be prepared to help the athlete achieve better fluid replacement in subsequent exercise sessions, however if this has not been calculated, the athlete can monitor changes in urinating habits - urine colour, frequency and volume.