Hydration

Research has shown that a fluid deficit as little as 2% will impair exercise performance (eg a deficit of 1.2 litres for a 60kg athlete). Some effects of dehydration include an increases perception of exertion (ie increased heart rate), fatigue and reduced mental function. This can be critical in a sport such as judo where an athlete’s concentration and decision-making ability are paramount.

At the National Team training camp at the Australian Institute of Sport in Canberra I was at recently, we were tested for hydration twice – on the first and fifth days of the camp. The test involves submitting a urine sample (taken first thing in the morning) to the lab for testing. Most athletes came into the camp hydrated, but a large portion of athletes were dehydrated later in the camp. This could be due to the athletes not adequately replacing the fluids lost during training sessions. Sometimes it is easy to become dehydrated if you are not consciously aware of your hydration levels (this is particularly so during the winter months).

Here are some tips for staying hydrated:
• Drink regularly throughout the day. Have a drink with all meals and snacks.
• Immediately before exercise commences, consume 200-600 ml of fluid.
• For exercise sessions longer than 30 minutes, aim to match previous fluid losses as closely as possible.
• Begin drinking early in the exercise session and continue to drink small amounts regularly. Water or sports drinks (for sessions longer than 90 minutes) are the best options.
• Replace any residual fluid deficit after exercise. You will need to drink 150% of any fluid deficit in the 4-6 hours after exercise to account for ongoing sweat and urinary losses.

See the Australian Institute of Sport website http://www.ausport.gov.au/ais/nutrition/factsheets/hydration2/fluid_-_who_needs_it