Electrolytes for Athletes: The Overlooked Key to Performance, Recovery and Hydration

Most people think electrolytes are just something you sip during a tough session or grab from a sports drink after training. But if you’re an athlete pushing your limits, whether in the gym, on the track, or during a long endurance session, electrolytes are far more than a hydration hack.

They’re essential for muscle function, recovery, endurance and even how sharp your brain feels under fatigue. In this blog, we’ll break down what electrolytes actually do, why they matter for athletic performance, and how to manage them for real results, not guesswork.

Electrolytes are minerals that carry an electrical charge when dissolved in fluid. The key ones include:

• Sodium
• Potassium
• Magnesium
• Calcium
• Chloride, phosphate and bicarbonate

For athletes, electrolytes help with:

• Fluid balance and hydration
• Muscle contraction and nerve signals
• Preventing cramps and fatigue
• Recovery and pH regulation
• Thermoregulation in the heat

Even small shifts in electrolyte balance can throw your body off, leading to under-performance, brain fog or that frustrating session where you just can’t switch on.

Sodium is the main electrolyte lost in sweat and it's absolutely vital for performance. It keeps blood volume stable, helps your muscles contract properly and plays a key role in absorbing both water and glucose in the gut.

Athletes can lose anywhere from 500 mg to over 1500 mg of sodium per litre of sweat, especially in hot or humid conditions. If you’re training hard and not replacing sodium, you’re not just risking cramps. You’re risking endurance, power output and even your safety.

Quick tip
If your sessions last longer than 60 minutes or you finish training with visible salt marks on your skin or clothes, you likely need more than just water. A solid electrolyte strategy is essential.

Potassium works closely with sodium to keep things firing properly. It helps regulate nerve impulses, supports cardiovascular function and ensures muscles contract and relax the way they should.

Low potassium can show up as:

• Cramping
• Muscle weakness or fatigue
• Sluggish coordination

You’ll find potassium in plenty of whole foods like bananas, potatoes, oranges, leafy greens and legumes. It’s usually easy to get enough through food unless you’re in a big deficit or losing lots through sweat daily.

Magnesium supports over 300 enzyme reactions, many tied to energy production, muscle recovery and nervous system regulation. It’s also essential for ATP production, which fuels your cells.

• If you’re low in magnesium, you might notice:
• Tight or twitchy muscles
• Poor sleep
• Slower recovery between sessions
• More inflammation or soreness

Athletes on lower-calorie diets or with high training loads often benefit from magnesium-rich foods or targeted supplementation if needed.

Calcium gets most of its spotlight for bone health, but it’s just as important for muscle contractions, nerve function and fat metabolism during training.

Low calcium can lead to:

• Less force output
• Muscle fatigue
• Higher risk of stress fractures, especially in runners or female athletes with low energy intake

You can get calcium from dairy, fortified plant-based milks, small fish with bones like sardines and leafy greens.

When you’re fuelling during longer or more intense sessions, combining sodium and carbohydrates actually improves absorption in the gut. The two work together to help your body pull in more fluid and glucose, meaning better hydration and more usable energy.

This is especially useful for:

• Long endurance events
• CrossFit-style sessions or metcons
• Heavy hypertrophy training blocks
• Hot-weather training or comp prep

Don’t just sip plain water and slam carbs. The combination matters.

Think your hydration is fine? These common symptoms often signal electrolyte imbalance:

• Muscle cramps or twitching
• Headaches or brain fog during sessions
• Dizziness or feeling flat post-training
• Salt crust on your skin or clothes
• Reduced endurance or early fatigue
• Nausea or GI discomfort during long sessions

These signs are often misattributed to poor sleep or general fatigue, but hydration and electrolytes are usually the missing link.

Plain water doesn’t contain electrolytes. If you drink a lot of it without replacing sodium, you can actually make things worse by diluting your blood sodium levels. This can lead to hyponatraemia, which is dangerous and often mistaken for dehydration.

Hydration isn’t just about how much fluid you take in. It’s about the balance of water and minerals in your system. Without that balance, performance suffers.

Some athletes sweat heavily and lose a lot of salt. Others sweat less but still drop key minerals. Two people doing the same session in the same environment can have completely different hydration needs.

Sweat rate and sodium loss are influenced by:

• Genetics

• Heat, humidity and clothing

• Acclimatisation level

• Diet, caffeine and hydration status

• Training intensity and session length

Generic advice doesn’t work for high performers. If you’ve never tracked your sweat rate or sodium loss, this is a valuable place to start.

Hormonal changes across the menstrual cycle can influence how female athletes retain fluid, regulate sodium and respond to training loads.

In the second half of the cycle, body temperature tends to rise and sodium losses may increase. Some women may feel flatter, more fatigued or prone to overheating if electrolytes are neglected during this phase.

Low energy availability also raises the risk of electrolyte imbalances. This is common in weight-class or aesthetic sports where calorie intake may not match energy output.

If you're a female athlete, pay attention to trends across your cycle, especially during higher-volume training blocks or competition prep.

You may benefit from electrolyte supplementation if you:

Train in hot or humid environments

• Do long or intense sessions

• Frequently experience muscle cramps

• See salt marks on your skin after training

• Follow a low-carb or ketogenic diet

• Struggle with energy, recovery or mental clarity

Look for a blend that contains:

• 500 to 1000 mg sodium

• 200 to 300 mg of Potassium

• 50 to 100 mg magnesium

• Minimal added sugars or fillers

The best products support hydration, not just flavour.

Before training
Start well-hydrated. Eat a salty meal or use a pre-load electrolyte mix if the session is early, long or hot.

During training
If training exceeds 60 minutes, sip a fluid with 300 to 800 mg sodium per litre. Some carbs will also help with absorption and energy.

After training
Rehydrate with 150 percent of the fluid lost in training. Include electrolytes either via a supplement or salty whole foods.

Day-to-day
Eat a diverse diet with plenty of mineral-rich foods. Monitor your recovery, performance and energy to adjust as needed.

Electrolytes aren’t just about avoiding cramps. They’re about supporting your nervous system, hydration, muscular function and ability to recover and adapt to training.

At Precision Applied, we take the guesswork out of it. Whether you’re chasing performance, transformation or high-level consistency, our team builds tailored plans that include hydration strategies backed by science and refined by coaching experience.

✅ Book a free consultation to build your personalised hydration strategy
💡 Explore our coaching for strength, endurance and hybrid athletes
📬 Reach out anytime if you have questions about performance, recovery or what’s holding you back