Hydration
How to Stay Hydrated During Hot Weather (And Why It Matters for Your Training)
When the weather heats up, most people focus on training harder, sweating more and “burning extra calories”. But one of the biggest things holding people back in summer is poor hydration.
Even mild dehydration can crush your performance, recovery, energy levels and even your mood.
If you’re training in hot weather and not paying attention to hydration and electrolytes, you’re making your sessions far harder than they need to be.
Why Hydration Matters for Training
Your body is made up mostly of water. Muscle tissue itself is around 75% water, so when you’re dehydrated, performance drops fast.
Even losing 1-2% of your bodyweight through sweat can lead to:
Reduced strength output
Lower endurance
Faster fatigue
Poor concentration
Higher heart rate during exercise
Worse recovery
Increased chance of cramps and headaches
Training in the heat increases sweat loss massively, especially during:
Weight training
Running
HIIT style workouts
Team sports
Outdoor conditioning sessions
A lot of people think they’re “just tired” during summer training, when in reality they’re massively under hydrated.
Water Alone Isn’t Always Enough
One of the biggest mistakes people make is simply drinking loads of plain water.
Yes, water matters.
But when you sweat, you don’t just lose water. You lose electrolytes too.
Electrolytes are minerals that help regulate:
Muscle contractions
Nerve function
Hydration balance
Blood pressure
Performance
The main electrolytes lost in sweat are:
Sodium
Potassium
Magnesium
Calcium
This is why sometimes people can drink loads of water and still feel:
Flat
Crampy
Weak
Dizzy
Low energy
They’re replacing fluid but not replacing minerals.
Sodium Is The Big One
Sodium gets demonised online, but for active people who sweat a lot, it’s incredibly important.
Low sodium levels can cause:
Muscle cramps
Fatigue
Headaches
Poor performance
Nausea
Brain fog
When you’re training hard in hot weather, sodium requirements go UP.
This is especially true if:
You sweat heavily
Your clothes show white salt marks after training
You train multiple times per day
You do long sessions
You work a physical job
You use saunas regularly
Cheap At-Home Electrolyte Options
You do NOT need expensive electrolyte supplements every day.
There are some incredibly cheap and effective options you can make at home.
1. Himalayan Salt In Water
Simple but effective.
Adding a small pinch of Himalayan salt to water can help replace sodium losses and improve hydration.
A basic homemade mix:
500-750ml water
Small pinch of Himalayan salt
Squeeze of lemon or lime
Optional: little bit of honey for taste and carbs
This works brilliantly before training or during hot days.
Despite the marketing hype, regular table salt also works perfectly fine for sodium replacement.
2. Add Salt To Meals
Most people massively under salt their food when trying to “eat healthy”.
If you’re sweating heavily, adding some extra salt to meals can genuinely improve:
Performance
Pumps in the gym
Energy
Hydration status
Especially around training.
3. Coconut Water
A decent natural option containing potassium and some electrolytes.
Not magic, but useful occasionally.
4. Fruit + Salt
A surprisingly effective combo.
Watermelon, oranges or pineapple with a little salt can actually help hydration while also providing carbohydrates for training performance.
5. Diluted Fruit Juice + Salt
A very cheap DIY sports drink:
Water
Small amount of orange juice
Pinch of salt
Simple. Effective. Cheap.
Signs You’re Probably Under Hydrated
A lot of people don’t realise they’re dehydrated until performance already drops.
Common signs include:
Dark yellow urine
Headaches
Feeling exhausted during sessions
Muscle cramps
Feeling dizzy standing up
Dry mouth
Poor pumps in the gym
Elevated heart rate during workouts
Practical Hydration Tips For Summer
Start Hydrating BEFORE Training
Trying to catch up during the session is too late.
Aim to drink consistently throughout the day.
Don’t Smash 3 Litres At Once
Your body absorbs fluids better steadily across the day.
Add Electrolytes Around Training
Especially if:
The session is over 60 minutes
It’s very hot
You’re a heavy sweater
Monitor Urine Colour
Pale yellow is usually a good sign.
Crystal clear constantly can actually mean over hydration.
Increase Fluids On Holiday
People massively underestimate dehydration abroad because:
Higher temperatures
More walking
Alcohol
Sun exposure
Air conditioning
Hydration Helps Fat Loss Too
A lot of people think summer fatigue means they need more caffeine.
Sometimes they simply need more fluids and sodium.
Better hydration can improve:
Energy levels
Training quality
Recovery
Appetite regulation
Sleep quality
Which all indirectly help fat loss progress.
Final Thoughts
You don’t need fancy supplements or overpriced hydration powders to stay hydrated.
The basics work:
Drink enough fluids
Replace electrolytes
Add some sodium
Stay consistent
If your training suddenly feels harder during hot weather, hydration is one of the first things you should look at.
At One Fitness we help members understand the small things that make the biggest difference to results — because better progress is rarely about extremes, it’s about consistently doing the basics well.
Here is a free calculator of how much water you should be aiming for.
Hydration Calculator
Find out roughly how much water you should drink daily based on your bodyweight and exercise levels.
Recommended Daily Water Intake
Bodyweight (kg) × 35ml + 1L per hour of exercise
