Example Recommendation
Philadelphia Half Marathon · November 23 · Returning runner · 12 mi/wk
Leave blank if unsure — we'll use your experience level.
How long to train for a half marathon
The right training window depends on your current fitness. Here's how many weeks each type of runner typically needs:
| Runner type | Training weeks | Notes |
|---|---|---|
| Returning / beginner | 16 weeks | Build base from scratch safely |
| Intermediate (15–25 mi/wk) | 12–14 weeks | Has aerobic base, needs race-specific work |
| Advanced (25+ mi/wk) | 10–12 weeks | Focus on quality, not base building |
Why your current weekly mileage matters
Your training start date isn't just about plan length — it's about how ready your body is when training begins. A runner averaging 20 miles per week can step into a 12-week half marathon plan right away. A runner averaging 5 miles per week needs more time to build a base first, or risks injury from ramping too quickly.
Once you know your start date, the half marathon training plan generator builds your full schedule from that date through race day — with target paces for every run.
What if your race is closer than your ideal training window?
If your race is less than 4 weeks away, a traditional training plan won't help — focus on easy running and make sure you have a solid race-day strategy.
If your ideal start date has passed but you still have 8–12 weeks until race day, you're behind schedule but not out of options. A compressed plan can still get you to the finish line safely. The key is honest goal-setting — you may need to prioritize finishing over a time goal.
What to do before training officially starts
If your ideal start date is still several weeks away, use that time for base building: easy running 3–4 days per week at a comfortable, conversational pace. Aim for 15–20 minutes per session and build gradually. The goal isn't fitness gains — it's creating a foundation so your body can absorb the structured training ahead.
No tempo runs, no intervals — just easy, consistent running that makes week 1 of your formal plan feel approachable instead of overwhelming.