A 12-Week Half Marathon Training Plan for First-Timers

This plan assumes you can currently run 5 kilometres without stopping and have been running at least twice a week for the last month. If that's not quite you yet, spend two to three weeks building that base first, our zero-to-running guide covers exactly that groundwork. If you're already there, this plan takes you from a comfortable 5K to a finished half marathon in 12 weeks.

How this plan is structured

Four runs a week: one easy run, one workout (intervals or tempo), one medium run, and one long run that grows steadily. Two full rest or cross-training days. The long run is the backbone, everything else supports it. Effort matters more than pace here: your easy runs should feel genuinely easy, conversational, not a slow version of hard.

The plan, week by week

How to adjust this plan

• If a week feels too much, repeat the previous week instead of skipping ahead. Losing a week to fatigue is cheaper than losing two weeks to injury.
• Cutback weeks (4, 7, 11) exist on purpose, don't skip them just because you're feeling strong. They're what let weeks 5-10 actually work.
• If you miss a run, don't try to make it up by doubling the next one. Just continue the schedule from where you are.
• Hot, humid weeks (most of India, most of the year) may mean slowing your easy pace by 30-45 seconds per km to keep effort honest. See training through the monsoon and heat acclimatisation for specifics.

The three mistakes that derail this plan

Running every easy run too fast is the biggest one, it leaves you too tired for the workouts and long runs that actually build fitness. Skipping the taper is second, cutting volume in the final two weeks feels counterintuitive when you're fit and eager, but it's what lets that fitness show up on race day rather than being buried under fatigue. Trying a new shoe, gel, or breakfast on race morning is the third, test everything in this plan's long runs first, never for the first time on the day that matters.