Moving from 5K toward 10K or a half marathon is primarily an endurance-building task, not a test of how hard every run can be.

Training & Fitness - Running & endurance

Training for a 10K or half marathon

Last reviewed 3 August 2026. How we write this.

Moving from 5K toward 10K or a half marathon is primarily an endurance-building task, not a test of how hard every run can be.

A useful week normally contains mostly easy running, a gradually developing longer run and, once the base is stable, a smaller amount of purposeful faster work.

Progress one demand at a time

Establish regular weekly running before stretching the long run.
Avoid simultaneously increasing distance, speed and frequency.
Practise hydration and fuel during longer sessions rather than improvising on race day.
Use an easier week when fatigue is accumulating.

General education only. Training needs to be adapted to the individual. Stop and seek appropriate clinical help for chest pain, fainting, severe breathlessness, neurological symptoms or significant/worsening pain.

Related in this classroom

Couch to 5K: how beginners should start running (9 min read)
How to train for a marathon (11 min read)
Easy running and Zone 2 (8 min read)
Tempo and threshold training (8 min read)

Sources for this classroom

Educational content only. Not medical advice, diagnosis or treatment. Always consult a qualified healthcare professional before changing your health regimen.