Hydration and fuelling plans depend on the length of the outing, conditions, access to supplies and the individual runner. Start by mapping those practical constraints. A bottle size or a gel brand is not a complete plan.
Separate everyday hydration from race logistics
The NHS hydration guidance explains that fluid needs can increase with heat and prolonged physical activity. Its general daily guidance is not a fixed hourly prescription for running.
For a short outing close to home, the carrying problem differs from a long route with no accessible water. Identify where supplies are available and whether those locations will be open. For an event, use the current organiser's information about stations and products rather than relying on a previous year's details.
Practise the method before race day
Test the foods, drinks, packaging and carrying method you intend to use on suitable training outings. Record what you took, when and how it felt. Opening a packet with cold hands, reaching a soft flask or tolerating a drink while moving are practical issues a shopping list does not answer.
The athletics nutrition literature emphasises matching plans to the event and the athlete. See the World Athletics nutrition consensus. A sports dietitian can help with individual needs or recurring problems; this guide does not prescribe one intake for everyone.
Understand “hitting the wall” cautiously
A difficult late-race slowdown is not evidence of one simple cause that a particular gel would fix. Pacing, preparation, conditions and nutrition can all require review. Do not interpret feeling seriously unwell as an ordinary barrier to push through. Stop and seek appropriate help when symptoms concern you.
Check the carrying setup
Fill bottles before testing a belt or pack. Check that it stays secure, can be cleaned and lets you reach supplies when stopped. Include a plan for a closed station, a lost bottle or a route change. In heat, revisit whether the outing should happen at all; see heat and humidity.
Use a route brief to make supply points and fallback options clear to a group. A running app can help organise those details, but it cannot guarantee hydration, diagnose illness or remove the need to adapt the plan.