How to train for a half marathon in 3 months is one of the most common questions new runners ask. And rightly so. Three months feels achievable. It’s long enough to build real endurance, yet short enough to stay focused.
The good news? For most runners, 12 weeks is ideal.
In this guide, you’ll learn exactly how to structure your training, how many miles to run, what pace to train at, and how to arrive at race day feeling strong instead of exhausted.
Can You Really Train for a Half Marathon in 3 Months?
Yes — but your starting point matters.
If you can already run 5K comfortably, 12 weeks is perfect.
If you run occasionally, three months is still realistic.
However, if you are starting from zero, begin with a short run-walk phase for the first two to three weeks.
In other words, the goal is progression, not punishment.
Because consistency beats intensity every time, your focus should be steady improvement rather than dramatic jumps in mileage.
What a 12-Week Half Marathon Plan Should Include
When learning how to train for a half marathon in 3 months, structure is everything.
Your weekly training should include:
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2–3 easy runs
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1 long run
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1 optional tempo or speed session
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1–2 rest or cross-training days
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Basic strength training
Although it might be tempting to run hard every session, most of your training should feel comfortable. In fact, around 80% of your miles should be at an easy, conversational pace.
Weeks 1–4: Build Your Base
During the first month, your only job is to build consistency.
Run three times per week.
Keep your pace relaxed.
Gradually extend your long run from 5–6 miles up to 7–8 miles.
At this stage, you are teaching your body to handle distance. Therefore, resist the urge to test your speed.
Add two short strength sessions each week. Focus on glutes, hamstrings, calves and core. This will protect you later.
Weeks 5–8: Increase Strength and Endurance
Now your training becomes more structured.
Increase to three or four runs per week.
Extend your long run to 9–11 miles.
Introduce one weekly tempo effort lasting 20–30 minutes.
A tempo run should feel “comfortably hard.” You can speak in short phrases, but not full sentences.
However, keep your easy runs genuinely easy. Because fatigue accumulates quickly at this stage, recovery becomes more important than ever.
Weeks 9–11: Peak Phase
This is where confidence grows.
Your long run should reach 12–13 miles at least once.
Maintain one controlled tempo session per week.
Keep your easy mileage steady.
Importantly, this is not the time to chase personal bests in training. Instead, focus on rhythm and consistency.
Sleep well. Eat well. Hydrate properly.
Because you are close to race day, every small recovery habit matters.
Week 12: Taper and Freshen Up
Although it may feel strange, you must reduce your mileage in the final week.
Cut volume by roughly 30–40%.
Keep runs short and relaxed.
Avoid heavy strength training.
This taper allows your body to absorb the work you’ve done. As a result, you will feel fresher and stronger on race morning.
How Many Miles Per Week Do You Need?
Most runners training for a half marathon in 3 months peak between:
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20–30 miles per week (beginner to intermediate)
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30–40 miles per week (more experienced runners)
However, more mileage is not always better. Instead, increase weekly distance gradually, ideally no more than 10% at a time.
Because injury often comes from sudden spikes, patience wins.
What Pace Should You Run?
Your easy pace should feel conversational. If you cannot speak in full sentences, slow down.
Tempo pace should feel controlled but challenging.
Above all, save true race effort for race day.
When you train smart, you improve faster.
Strength Training and Injury Prevention
If you want to train for a half marathon in 3 months without setbacks, strength work is essential.
Twice per week, include:
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Glute bridges
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Lunges
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Deadlifts
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Calf raises
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Core exercises
These movements build durability. Therefore, you are far less likely to struggle with common problems like shin splints or knee pain.
Nutrition and Recovery Tips
As your mileage increases, so should your attention to recovery.
Eat carbohydrates before long runs.
Refuel within 60 minutes afterwards.
Drink water consistently throughout the day.
Aim for at least seven hours of sleep per night.
Moreover, light mobility work or foam rolling can keep tight muscles under control.
Because recovery drives adaptation, rest is not weakness — it is strategy.
Common Mistakes to Avoid
Many runners sabotage their 12-week plan by:
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Increasing mileage too quickly
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Racing every training run
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Ignoring rest days
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Trying new shoes close to race day
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Skipping long runs
Although motivation will fluctuate, discipline creates results.
Is Three Months Really Enough?
Yes. For most runners, three months is enough to train for a half marathon safely and successfully.
If you follow a structured plan, increase mileage gradually, and prioritise recovery, you will arrive at the start line ready.
More importantly, you will build confidence along the way.
Because finishing strong feels far better than finishing exhausted.
Resources: https://www.mymottiv.com/half-marathon-training-plan/12-week-beginner-half-marathon-training-plan