It’s easy to think hydration only matters in the summer, but your body still loses a significant amount of fluid during winter runs—you just don’t notice it as much.

Cold air is drier, which means you lose more water through breathing. Add in layers, wind, and longer base-building miles, and dehydration can sneak up fast. Even mild dehydration can lead to:

• Higher perceived effort (easy runs feel harder)
• Slower recovery
• Increased muscle tightness and cramping
• Headaches and fatigue later in the day

Another common winter mistake? Waiting until you feel thirsty. In cold weather, your thirst response is blunted, so by the time you notice it, you’re already behind.

The takeaway:

• Start runs already hydrated
• Sip water regularly throughout the day, not just around workouts
• For runs longer than ~60 minutes, consider fluids with electrolytes—even in winter

Hydration isn’t about weather—it’s about supporting performance and recovery year-round.