This is our second to last post before the big event…. How exciting (the last being shoulder impingement) and it’s sneaked in by popular demand……. It’s all about water.

How much, when and why.

What’s the big deal?

Being as little as 2% dehydrated can increase fatigue, reduce athletic performance and increase your risk of heat stress. On the other hand being well hydrated and fuelling correctly, you have the capacity to tolerate longer and more intense exercise and recover quicker.

  • Water is basic, unpretentious and flows naturally into and through life

  • 60 – 70% of your body weight is water

  • Approx. 70% of your muscle is water

  • Water plays an integral role in the body’s optimal functioning


Ideally consume 2-3 litres a day (remember there is water within food)

If you can……

  • Drink 500ml of fluid 4hrs before exercise

  • Then sip 150-350ml of additional fluid just before exercise.

  • 14-27 oz/hour (0.4-0.8 litres per/hr) depending on weight, intensity and need.

How do you know if you are hydrated?

Check your pee!!!!!

Every athlete is unique in what his/her fluid intake would be during an endurance event/ training. Factors such as sweat rate, temperature, gender, size, weight, speed, metabolism and muscle mass all have an influence.

So how much do I need???

For an easy way to work out how much water you need follow the simple steps below……

  1. Wear minimal clothing

  2. Pass urine before weighing yourself (lbs)

  3. Perform exercise session

  4. Weigh yourself (lbs) as soon as possible after exercise (rub off any sweat) and before passing urine

  5. Record the amount of fluid you drink during training

Weight before – weight after. E.g 160lbs- 159lbs = 1lbs

Covert to fluid loss 1lbs = 16 oz

Fluid consumed 16oz

Add fluid loss to fluid consumed – 16+16= 32oz

Divide this by 4 to determine how much you should drink every 15min = 8oz

What happens if you drink too much???

Drinking too much water can lower the concentration of sodium in our body, and when this happens it is called hyponatremia. Producing symptoms such as…..

  • Fatigue

  • Nausea

  • Headache

  • Disorientation

  • Confusion

  • Swelling

  • Seizures

Therefore, remember not to take on too much water when you exercise. Salt (electrolytes) intake can help decrease the risk of developing hyponatremia, especially in salty sweaters! When training this can come from food, drinks or gels.

But remember to consume gels with more than ~150 ml fluid as otherwise they won’t hydrate you!! Tummy cramps are common so try out different types to find one that suits.

Isotonic drinks

Contains similar concentrations of salt and sugar as in the human body, therefore you can use these to refuel and hydrate.

What are Electrolytes?

The first role they serve is to facilitate proper muscle contraction. This is dependent upon the presence of calcium, sodium, and potassium. Without sufficient levels of these key electrolytes muscle weakness or severe muscle contractions (cramping or spasm) may occur.

The second role they serve is facilitating hydration. Sodium and potassium serve to replenish the body’s water and electrolyte level after dehydration caused by exercise.

So during training….

<1 hour – stick to water

>1 hour - Consuming carbohydrates (with electrolytes) can help delay fatigue

30 – 60g carbs / hour

Remember it takes 30 minutes for the carbs to be absorbed by the body


  • Don’t do anything you haven’t tried before

  • Plan your race

  • Prepare your food


Got a niggle and want to speak to someone - Email elle@studio57clinic.co.uk

All Triathletes get a 20% off their initial consultation - quote Brighton and Hove Triathlon on booking www.studio57clinic.co.uk, 01273 711399 or email info@studio57clinic.co.uk


You also get 20% off at StrideUK- they assess your running gait from a musculo-skeletal angle from head to toe (they help with prolonged injury, running forma and performance) www.strideuk.com

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