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.

The human brain is approximately 75% water, 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. It is involved in many, 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.

You may have heard the old one of 'drink 8 cups of water a day' which is fairly generic. Everything is context dependent but here are some guidelines to start from.

A baseline for male clients is 2.5 litres per day.

A baseline for female clients is 2 litres per day.

Pictured below is a 2.2 litre water bottle available from most online supplement companies and this should help give you a visual indication of around how much you need (at baseline). It's handy to pick one of these up and to have it close at hand throughout the day.

After that things can change depending on the climate the person lives in (I think we are okay in Ireland!) and activity level. If you train to higher intensities and sweat quite a lot (people have different levels of sweat rate) then you may need more.

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, or generally at any point in the day whether you train or not. Be aware of water intake in that you should never suddenly think 'wow, I'm very thirsty.

Performance aside, 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 poor energy. 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. Do note that if you are taking a multivitamin it can change the colour of your urine to 4 or 5, so if you feel good and that you take in enough water but your urine has a yellow tiny you're probably fine.

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 fruit in your diet this contributes to hydration as they are a source of fluid for the body as well. Foods containing water do contribute to overall intake, just don't try to rely on them without drinking water itself.

Exercise changes things and everybody is slightly different so just use your own judgement call to adjust things PAST the baseline.

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.

One last thing, try and stack your water intake earlier in the day yet in some way spread out, otherwise you'll be making frequent trips to the bathroom and your sleep will get disrupted.


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, 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.


(1) https://www.outsideonline.com/2309646/your-guide-using-electrolytes-properly