Short Version.

You are most part water, drink enough every day (2-3 litres + then to thirst) to support health and energy levels. The more you exercise the more you need to focus on it as dehydration will negatively affect performance.

Long Version.

Water accounts for approximately 50-70% of a person’s body weight. Females are slightly lower down in that range, and males in the higher end. This is down to muscle mass containing 73% water, with fat holding just 10%. Males generally have more muscle mass so you can see where the difference occurs.

Last but not least, the human brain is approximately 75% so the high overall percentage should indicate just how important hydration is for general well-being…you are mostly made up of water.

Some of water’s main functions include to dissolve, transport and help flush out food/substances, it is a major component of blood, and it protects and lubricates tissue so we can see it plays a big part in many crucial roles in the body.

If you need any more proof of this it is estimated that you can go 3-4 days without water after which you will die, yet we can survive up to 3 weeks without food.

The guidelines for hydration are quite simple, but at the same time I have seen many slightly different position stands on what a coach will prescribe. I have my own, and this is it.

A baseline for male clients is 2.5 litres per day.

A baselines for female clients is 2 litres per day.

Pictured below is a 2.2 litre water bottle available from most online supplement companies.

This is just a general guideline and things will vary from person to person. Some of the factors affecting an individual are body weight, activity level, sweat rate and the climate in which the person lives.

Dehydration can affect performance, and if bad enough it can affect general cognitive function. I always say to my clients ‘if you step on to the gym floor feeling thirsty you’re in for a rough hour’. You shouldn’t feel thirsty walking in to a session.

I recommend that clients aim for this baseline and drink to thirst after that point if needed, and things change if someone partakes in intensive exercise over certain periods of time. With athletes the requirements become more specific, weight loss in a session and/or sweat rates can be calculated to establish what is needed.

Outside of performance it is a strong belief of mine that no adult should struggle for energy day to day outside of having a medical condition. Poor hydration is a contributing factor to someone feeling lethargic all the time or suffering from slumps. It’s one piece of the puzzle of solving the problem, but it’s an important piece.

A way of checking hydration status is the colour of your urine as seen in the chart below.

1-3 is hydrated, but anything below that and you will need to take water on. The problem with something like this is that if you are taking a multivitamin it can change the colour of your urine to 4 or 5.

Once you’re aware of this you’ll be able to identify when that has happened – it may be 4 or 5 for close to the time you’ve take the multi-vitamin, but if you’re not thirsty/fatigued you know everything is as it should be.

In summary, aim for the baseline targets provided and drink to thirst past that if needed. If you have plenty of vegetables and some fruit in your diet you should be fine as they are a source of fluid for the body as well. Exercise changes things and everybody is slightly different so just use your own judgement call to adjust things.

Hydration is incredibly important for health and also affects performance levels but the guidelines are simple. This should be an easy one on the list to tick off.

Further Reading


Electrolytes are the following group of 6 salts – Sodium, Potassium, Magnesium, Calcium, Phosphate and Chloride – which are responsible for controlling the flow of water in and out of our cells and nerve impulses throughout our body.

They play a huge role in regulating a host of functions  – muscle contraction, metabolism, blood pressure, the process of breathing. and even your heart beating.

A spark plug in a car delivers an electrical charge to start the engine, I like to visualise electrolytes as millions of these spark plugs which transfer electrical charges throughout the body to make everything happen.

You will most likely have heard about them in the context of ‘we lose electrolytes through sweat when we exercise’.

When you exercise you generate heat in the body, the mechanism to offset this is sweat generation. Evaporating sweat pulls heat off the body, thus regulating body temperature but electrolytes do get removed with sweat.

If enough are lost it will affect performance, and in severe cases it can cause problems with breathing, heart rate and blood pressure.

So, a question you may ask is ‘do I need to take on electrolytes every time I train?’.

For the average athlete, the length and intensity of exercise are the biggest factors that determine when you need to supplement.

Stavros Kavouras, director of the Hydration Science Lab at University of Arkansas had this to say on the matter in a recent article published (1).

“Unless you exercise for more than three hours, you don’t need to add electrolytes,” Kavouras says. “No one has complications related to electrolyte imbalance for anything, assuming you start your exercise in a balanced state.”

Electrolyte replenishment comes in to play for longer duration, endurance type events. As far as day to day training goes where you attend the gym for an hour or so everything should be fine. Focus on hydration, electrolytes come back in to the body through food and if you have a varied, healthy diet you can’t go wrong.