Importance of Fluid Intake

For some individuals there is a greater focus on fuelling and refuelling their body with food rather than fluids pre exercise and post exercise, as generally people are aware that the body needs more energy from food to carry out physical activity. However, water is one of the most essential nutrients required in the diet and must not be ignored. Water is essential for removing toxins from the body such as; lactic acid which occurs during physical activity and is necessary to assist in transporting nutrients around the body.

If insufficient water is consumed it can be detrimental to running performance and can affect you both physically and psychologically. It is essential that fluids are replaced not only during warm/hot conditions but also in cooler climates as the body does sweat in these conditions too. Sweating is the way that the body keeps an optimum core temperature so consuming water regularly is vital to assist with maintaining this core body temperature. Factors affecting sweat rate include: temperature, duration of exercise, speed of exercise, intensity of exercise, body weight, gender and the type of clothing worn, therefore the rate of sweating differs between individuals and the requirements for water by the individual also varies.

It is therefore vital to drink water regularly to improve the hydration status in the body, particularly when exercising to ensure that the body is functioning efficiently and reduce the risk of dehydration.

Monitoring Hydration Levels

Prior to exercise and after exercise it is important to consume adequate water to ensure the body is hydrated, and by producing clear urine is a good indicator that you are well hydrated. To monitor your hydration status, assess both the colour and the volume of your urine present. If your urine is plentiful and a pale yellow colour then you are well hydrated, however if you have small amounts of dark urine then you need to drink more water to change the colour of your urine which will assist in the removal of toxins such as lactic acid from the body.
It is very important to stress that thirst is not a good indicator of fluid needs, it is a sign that excessive water loss has occurred which will result in the poor functioning of the body affecting both the psychological and physiological state of the body.

Effects of Dehydration

Dehydration inhibits the body’s ability to exercise at an optimum level and both conditions can have a negative impact on your running performance. If you are significantly dehydrated it can take the body 24 hours to become properly hydrated which will reduce the efficiency of the body to exercise and then delay the recovery process after a workout.

Dehydration can affect your mental state and, for example, can cause: light headedness, headaches and reduced concentration levels. There are also physical symptoms including: tiredness, fatigue, cramps (sodium loss), sickness, diarrhoea and humidity. Excessive intake of caffeine (found in coffee, tea, chocolate), inadequate fluid replacement, excessive alcohol consumption and induced high sweat rates caused by a sauna or steam room can all increase the risk of dehydration.

Electrolytes (sodium and potassium) need to be replaced after exercise to prevent an imbalance of these electrolytes which if not replaced can result in muscle cramps and stomach cramps. An example of a post exercise snack to replace these electrolytes is consuming a low fat cheese sandwich and a banana ‘washed down’ with a bottle of water.

How Much Water Should I Drink?

As the amount of water varies between individuals due to different rates of sweating combined with other factors, for example temperature or duration of exercise, it is important to monitor your own levels of hydration by checking your urine. Water should be consumed before exercise (30-60 minutes prior), during and after exercise. For exercise lasting 60-90 minutes water is an adequate fluid replacement immediately after exercise. It is not necessary to consume a sports drink providing that the diet is nutritionally balanced with carbohydrate and electrolytes (sodium & potassium). However, if your exercise lasts longer than 90 minutes, consuming a sports drink may be beneficial to improve running performance and aid the recovery process involving the removal of toxins.

To assist with increasing fluid intake in the body eating foods with a high water content such as fruits (berries, apples, oranges, melons) and a wide range of vegetables can help. These foods also provide energy from the natural sugar found in them, however it is recommended that consuming 2 litres of water throughout the day will be beneficial to aid recovery and to reduce the symptoms of dehydration which may occur as a result of inadequate fluid intake.

To calculate the amount of water to be consumed weigh yourself without clothes before exercise and then immediately after exercise allowing for any water taken during exercise (this needs to be deducted). For every pound lost it is advised to drink 500ml of water to replace water loss.