When you're out running – especially over longer distances or at higher intensities – staying on top of hydration and fueling can make a huge difference in how your body performs. In this guide, I’ll share practical, evidence-based recommendations from my work as both an elite trail runner and a sports science graduate specializing in endurance sports.
I’m Max Boderskov, founder of Pika Wear. My goal is to simplify what you need to know about fluids and fuel – without overcomplicating it, but still rooted in science and real-world experience.
How much fluid do you need?
Hydration needs vary based on temperature, intensity, and how much you personally sweat. Here are some general guidelines I use for myself and the athletes I coach:
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Cold conditions (<15 °C / 59°F): 300–500 ml per hour
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Moderate (15–25 °C / 59–77°F): 500–750 ml per hour
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Hot (>25 °C / 77°F+): 750–1000+ ml per hour
For longer sessions – or if you're a heavy sweater – adding 300–600 mg of sodium per hour can help maintain fluid balance and prevent cramps or energy dips.
If you're in doubt, I recommend that you do a sweat-rate test in race-conditions - this way you can dial in your fluid needs to your specific needs.
⚡ How much fuel do you need?
Carbohydrates are your main fuel source during running. The longer and harder you go, the more you need. Here’s a simple overview:
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<30 minutes: No fuel needed – possibly a mouth rinse
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30–60 minutes (high intensity): ~30 g/hour
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1–2 hours (high intensity): ~60 g/hour
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2–4 hours (low intensity): ~60 g/hour
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2 hours (racing intensity): 90+ g/hour
Whether you choose gels, drink mix, or a combination doesn’t matter much – but it’s critical to practice it in training. High doses (60–90+ g/hour) typically require gut adaptation over time.
How do you carry it?
Even the best fueling plan only works if you can access it easily – without interrupting your stride. I designed Pika Running Tights to make this simpler: no need for a vest or belt, but still room to bring what matters.
The tights feature an integrated waistband with space for soft flasks, gels, and small essentials like a jacket or gloves. Our Pika Running Soft Flasks are built to fit perfectly in the waistband – they stay snug and bounce-free, even on technical terrain.
My typical setup for a 90–120 minute trail run looks like this:
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1 × 500 ml soft flask with carb mix
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1–3 gels
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Water-refill of the soft flask if needed
That gives me around 90–150 g of carbs, consistent hydration, and zero gear distractions.
Final thoughts
This doesn’t need to be complicated. Start small, experiment during your training, and figure out what works for you.
With the right hydration and fueling approach, you’ll feel stronger, go longer, and enjoy your runs more – whether it’s a morning trail loop or a big race day.
– Max Boderskov
Elite trail runner, M.Sc. in Sports Science, and founder of Pika Wear