Running culture swings between two extremes: carry gels on every run, or never eat anything at all. The right answer depends on duration, heat, and what you are training for.
Short runs
If you start hydrated and conditions are reasonable, ordinary shorter runs do not require carrying water or fuel. A 40-minute easy run does not need a gel.
On ordinary runs, drink to thirst. Use thirst and conditions rather than a rigid rule.
Long runs and hot days
Fuel becomes more important as duration approaches roughly two hours or more. For those runs, and for long or hot efforts in general, plan:
- Fluid, matched to heat and sweat loss
- Sodium, to support plasma volume and fluid absorption
- Carbohydrate, to keep fuel available as duration climbs
Do not overdrink
More fluid is not always better. Overdrinking can dilute blood sodium, a condition called hyponatremia, and it is a genuine risk in long events.
Train your gut
Your digestive system adapts to fueling just like your legs adapt to training.
- Practice in long runs, not on race day.
- Increase intake gradually as your gut adapts.
- Combine carbohydrate types. Mixing sugars uses multiple absorption pathways, so you can take in more without stomach trouble.
Carb loading can be simple
Carbohydrate loading does not require a depletion phase or a heavy meal that is hard to digest. Simple, familiar, carbohydrate-rich food in the days before a long race is enough.
Match the plan to you
Nutrition plans should fit the duration of the event, the heat, your sweat loss, and your individual tolerance. What works for one runner can upset another.
How Catherine applies this
Catherine plans fueling around duration and conditions: drink to thirst on ordinary runs, and a specific fluid, sodium, and carbohydrate plan for runs approaching two hours or more. Long runs are used to train your gut, so race-day fueling is rehearsed, not improvised.