How Much Water Should You Really Drink – and Should it BE Water?!
Recent research questions how much fluid we really need when we exercise and what that fluid needs to be.
- Are you going to train for more than an hour?
- Are you going to be training indoors in the warm or in cold environments?
- Are you going to be training at altitude
- Do you sweat a lot of salt
- Are you carrying any extra weight
- Will you be travelling to get to where you are exercising?
- Drinking too little.
- Drinking too much.
- Failing to individualise what you drink – no two people are alike and have the same needs!
What IS dehydration?
If you are a runner who weighs 125 lbs before a run and you lose 2.5 lb when you exercise then you are going to be dehydrated. If you weigh 200 lbs and you lose 4lbs of weight after exercise. When should you take on fluid? Two hours before you perform the exercise is too late. You need to start hydrating days before or adopt a daily hydration strategy. Most of all you need to know what you need as an individual.
What do you need?
An athlete of 130 lbs needs 70 fluid ounces per day An athlete of 280 lbs needs 140 fluid ounces per day. Body weight divided by 2 = the fluid ounces needed per day to remain hydrated.
Where does this come from?
Friut Food Caffeine can hydrate you but it is a diuretic i.e. encourages you to pee but this is not a big problem as long as you drink regularly. Alcohol is not a good hydrator.
Your urine is a great indicator of your state of hydration. An area of your brain, the hypothalamus, controls the thirst mechanism, which tells you whether you need to take on fluid or not. You need to LOOK at your urine though. It should be pale yellow, not dark yellow or cloudy.
Factors that indicate you need to increase your fluid intake.
- Higher temperatures
- Intensity of exercise
- The equipment you are carrying and what you are wearing
- How much you weigh – the more you weigh the more you need to hydrate yourself
- Poor acclimatisation – you need one week to adjust to your surroundings
- Air travel – you may not feel thirsty when you fly but it does dehydrate your body
- Dietary composition
- Health conditions
What to do before you exercise
Two hours before – take on 14 – 22 fluid ounces of fluid 15 minutes before – take on 4 – 16 fluid ounces of fluid At the start of a race i.e. during the first 15 – 20 minutes take on 14 – 47 fluid ounces of fluid At the end of a race take on 16 – 24 fluid ounces of fluid per lb of weight you have lost Sweat rates are variable – on average you lose between 16 and 64 fluid ounces per hour Sports like rugby cause you to lose the most and less active sports such as cricket of cycling are less demanding.
How to individualise how much fluid you need to take
Warm up for 10 minutes at typical intensity then weigh yourself Exercise for 30 minutes and weigh yourself again before you pass water Repeat and then see the average amount you lose. For every lb you lose, you should drink 16 – 24 fluid ounces or 1 pint per lb of weight lost.
What should you hydrate with?
Water is not always ideal. Why?
- You can lose your sense of thirst in a game or race
- You may drink less if just water
- If you drink too much you can become low in sodium, which is dangerous to health
- It does not replace carbohydrate loss
- It does not replace lost electrolytes
- It is not absorbed very fast into the blood stream
What is better than water?
- Check the osmotic concentration of a drink – also called the osmolarity. It should tell you this on the label of the drink you buy.
- A good health drink contains between 4 – 8% carbohydrate – NOT more.
- A good health drink should contain a mix of sugars
- Sodium levels should be between 120 and 170 mg/8 ounces.
- Potassium levels should be between 20 – 50 mg/8 ounces.
- No weird ingredients
Why all the fuss about health drinks?
- If they taste good then you will be more likely to drink it over boring water!
- A drink containing sodium reduces your urine output so helps keep more fluid in your body and it also helps your thirst mechanism and improves the taste of the drink.
- Sweat means you lose 400 – 1500 mg of sodium per litre of sweat – it needs to be replaced!
Most of all you need to look at the label and choose a drink that is going to help to keep you hydrated in the best way for YOU! It is so important and you will feel better when you exercise too – whatever the level of expertise you have.