Hydration for Strength Training: The Simplest Way to Improve Performance
If I could only change one nutrition habit for most new clients, it probably wouldn't be protein.
It would be drinking enough water.
Hydration is one of the most overlooked parts of fitness, yet it affects almost everything your body does. Your energy, concentration, digestion, training performance and recovery all rely on having enough fluid available.
Before worrying about supplements, calorie tracking or nutrient timing, I'd rather make sure you're consistently hydrated.
It's one of the easiest wins available.
Why Hydration Matters
Your body is made up of trillions of cells, and every single one relies on water to function properly.
Water helps to:
Transport nutrients around the body.
Regulate body temperature.
Support digestion.
Lubricate joints.
Maintain blood volume and circulation.
Help muscles and nerves work properly.
Support concentration and cognitive performance.
On average, around 50–70% of the human body is water, depending on age, sex and body composition. If you're carrying more muscle, you'll generally carry more water too.
Because water is involved in so many systems, even mild dehydration can affect how you feel and perform.
What Happens When You're Dehydrated?
You don't have to become severely dehydrated before it starts having an effect.
Research consistently shows that losing around 2% of your body weight through fluid loss can reduce endurance performance and make exercise feel significantly harder. Greater dehydration can affect strength, power, decision-making and concentration.
For someone who weighs 100kg (roughly me), that's only about 2kg of fluid loss.
Signs you might be dehydrated include:
Feeling thirsty.
Dark yellow urine.
Dry mouth.
Headaches.
Feeling unusually tired.
Reduced concentration.
Feeling your workout is harder than it should be.
A lot of people live in this slightly dehydrated state every day and simply assume that's normal.
It isn't.
Don't Wait Until You're Thirsty
One thing that surprises people is that thirst is a late signal.
By the time you're noticeably thirsty, you're already beginning to replace water you've lost.
That doesn't mean you need to constantly force water down your neck.
It simply means it's better to drink regularly throughout the day than to realise at 7pm you've had one coffee and half a bottle of water.
Think of hydration as something you maintain rather than something you catch up on.
How Much Water Do You Actually Need?
The old "everyone needs 2 litres" advice is a decent starting point, but it's not a rule.
A better guide is:
30–40ml of water per kilogram of body weight each day.
A rough guide
60kg1.8–2.4L
70kg2.1–2.8L
80kg 2.4–3.2L
90kg 2.7–3.6L
100kg 3.0–4.0L
These figures include water from drinks. Food contributes some fluid too, particularly fruit and vegetables.
You'll Need More If You...
Increase your intake if you:
Train for long periods.
Sweat heavily.
Exercise in hot weather.
Drink lots of caffeine or alcohol.
Are recovering from illness.
A hard strength session or long HYROX workout can easily require another 500ml–1L+ depending on how much you sweat.
What Should You Drink?
The vast majority of the time:
Plain water is perfect.
Tap water is absolutely fine
If you live in the UK, tap water is safe, inexpensive and a great option.
Filtered or mineral water is also perfectly good if you prefer the taste, but don't feel like buying expensive bottled water is going to transform your results.
Tea and Coffee Count
This surprises people.
Tea and coffee do contribute towards your daily fluid intake.
Caffeine has a mild diuretic effect, but regular caffeine drinkers still gain hydration from coffee and tea.
So yes—your morning coffee counts.
It just shouldn't be your only drink.
When Are Electrolytes Useful?
Most gym sessions don't require electrolyte drinks.
They're useful if you're:
Sweating heavily.
Training for over an hour in the heat.
Doing long endurance sessions.
Losing lots of fluid through repeated exercise.
For a typical hour-long strength workout in Deptford, water is usually enough.
How I Recommend Building the Habit
Don't suddenly jump from one glass of water a day to four litres.
Build it gradually.
Choose the smallest target you're confident you'll complete.
Level 1 — Beginner
Drink one extra glass of water every day for one week.
Level 2 — Most People
Drink an extra 500ml every day for one week.
Level 3 — Bigger Lifters / Hot Weather
Drink an extra litre per day if your training and body size genuinely justify it.
The goal isn't perfection.
The goal is consistency.
Simple Ways to Drink More Water
These habits work far better than relying on willpower.
Drink a glass of water when you wake up.
Have a glass with every meal.
Keep a large water bottle with you at work or in the gym.
Refill it as soon as it's empty.
Drink before, during and after training rather than all at once afterwards.
The easier you make hydration, the less you have to think about it.
A Quick Way to Check Your Hydration
One of the simplest daily checks is urine colour.
Pale straw colour: You're probably well hydrated.
Dark yellow or amber: You probably need more fluid.
Completely clear all day: You may actually be drinking more than you need.
It's a simple guide—not a perfect scientific test—but it's useful for day-to-day life.
The Bottom Line
Hydration isn't exciting.
It won't sell as many supplements as a flashy pre-workout.
But it's one of the highest-return habits you can build.
If you're consistently hydrated you'll generally feel better, recover better and give yourself the best chance of performing well in training.
Before worrying about the finer details of nutrition, make this one automatic.
Carry a bottle. Drink regularly. Stay hydrated.