UK’s Best Sports Dietitian Gives Top 5 Tips to Meet Your Daily Fluid Requirements as an Active Individual

Jenaed Ruddock, UK sports dietitian nutritionist

Staying hydrated is one of the most critical yet overlooked aspects of athletic performance. Whether you're an elite athlete or someone who enjoys staying active, understanding your daily fluid requirements is essential for optimizing endurance, strength, and recovery.

A recent meta-analysis on fluid requirements for athletes (Suppiah et al.) confirms that even mild dehydration can lead to reduced cognitive function, impaired thermoregulation, and decreased physical performance. But how much fluid do you really need, and what counts towards your daily intake?

As one of the UK’s best sports dietitian, I’ll break down the top five tips to help you meet your fluid needs efficiently.

1. Know Your Daily Fluid Requirements

Research suggests that athletes should aim for 35-50ml of fluid per kg of body weight per day. However, this can vary based on factors such as training intensity, duration, sweat rate, and climate.

General guideline:

• A 70kg athlete would need approximately 2.5-3.5L of fluid per day.

• Training in hot and humid conditions increases needs significantly.

A simple way to check hydration is by monitoring urine color—pale yellow is ideal, while dark yellow or amber suggests dehydration.

2. Fluids Aren’t Just Water – What Counts?

Water is the primary source of hydration, but several other fluids contribute to your daily intake:

Electrolyte drinks – Ideal for replenishing lost sodium and potassium.

Milk and plant-based alternatives – Great sources of fluid with added protein and nutrients.

Fruits and vegetables – High-water-content foods like watermelon, cucumber, and oranges contribute significantly.

Herbal teas and low-caffeine beverages – Hydrating options that help keep fluid intake up without excessive stimulants.

3. Time Your Hydration Correctly

Drinking too much water in one go can lead to dilution of electrolytes, affecting performance and recovery. Instead:

• Start your day with 500ml of water.

• Sip fluids consistently throughout the day, aiming for 250-500ml per hour.

• Before training: Drink 400-600ml of fluid 2 hours before exercise.

• During training: Consume 500-1000ml per hour, depending on sweat loss.

• After training: Rehydrate with 1.5x the fluid lost to restore balance.

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4. Adapt Your Hydration Based on Sweat Rate

Every athlete has a unique sweat rate, meaning fluid requirements can vary significantly. To estimate your fluid loss:

1. Weigh yourself before and after a session.

2. 1kg lost = ~1L of fluid deficit.

3. Rehydrate accordingly with fluids containing electrolytes.

For athletes prone to heavy sweating, sodium intake is crucial to prevent hyponatremia (low blood sodium levels). Adding a pinch of salt to meals or choosing electrolyte-rich drinks can help maintain balance.

5. Create Hydration Habits to Meet Your Targets

Struggling to drink enough? Here are practical ways to hit your daily hydration goals:

✔ Carry a water bottle everywhere and track intake.

✔ Use reminders – Set phone alerts or link hydration to meals.

✔ Flavour water with fruit slices or electrolyte tablets for variety.

✔ Choose high-water-content foods like soups, smoothies, and juicy fruits.

✔ Monitor thirst cues – Being proactive is better than waiting until you’re thirsty.

Meeting your daily fluid needs is non-negotiable for optimal performance, recovery, and overall health. If you're unsure whether you're drinking enough, try tracking your intake for a few days and making adjustments accordingly.

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