This plan is for runners who:
- →Are training for their first marathon or returning after a long break
- →Want a personalized plan instead of a generic PDF
- →Have a goal finish time and want to know exactly what pace to run
- →Want structure without hiring a coach
- →Don't know where to start
16–20 weeks
plan options
5 paces
calculated from your goal
4 phases
Base · Build · Peak · Taper
Included
race strategy
Example: 16-week plan for a 4:00:00 marathon
Built by a real training engine — not a generic PDF
- ✓Adapts for Beginner, Intermediate, and Advanced runners
- ✓Builds Base → Build → Peak → Taper phases automatically
- ✓Calculates every training pace from your goal time
- ✓Built to get you to the starting line healthy — not just tired
Example: 20-week Beginner plan for a 4:20:00 marathon
Paces are calculated from your goal time — enter yours above to see your actual numbers.
Compare Beginner, Intermediate, and Advanced marathon plans
Pacerly generates three distinct marathon plans based on experience level. Here's how they differ across the key variables that determine how hard — and how safely — you can train.
| Beginner | Intermediate | Advanced | |
|---|---|---|---|
| Plan length | 16–20 weeks | 16–20 weeks | 12–20 weeks |
| Peak weekly mileage | ~40–42 mi | ~50–55 mi | ~60–65 mi |
| Longest run | 20 mi | 21 mi | 22 mi |
| Runs per week | 3–5 | 4–6 | 5–6 |
| Who it's for | Never run a marathon, or returning after a long break — conservative build, no structured quality sessions in early weeks | At least one marathon completed; running 20–30 mi/week — moderate volume with tempo and marathon-pace workouts | 35+ mi/week base, multiple marathons — high volume with structured long runs in peak phase |
When in doubt, pick one level down. It is much easier to add mileage mid-plan than to recover from an overuse injury.
What does a week actually look like?
Below are real mid-build weeks from each experience level — these are the workouts, mileage, and workout types the Pacerly plan engine generates. Week 8 of a 20-week plan sits squarely in the build phase, after the base is established but before peak mileage is reached.
Beginner — Week 8 of 20 · Long run: 15 mi · Weekly total: ~31 mi
| Day | Workout |
|---|---|
| Monday | Rest |
| Tuesday | Easy run — 4 mi |
| Wednesday | Tempo run — 5 mi (2 mi warm-up, 3 mi at tempo pace, cool-down) |
| Thursday | Easy run — 4 mi |
| Friday | Rest |
| Saturday | Long run — 15 mi |
| Sunday | Easy run — 3 mi |
Intermediate — Week 8 of 20 · Long run: 16 mi · Weekly total: ~45 mi
| Day | Workout |
|---|---|
| Monday | Rest |
| Tuesday | Easy run — 6 mi |
| Wednesday | Intervals — 7 mi (2 mi warm-up, 4×1200m at 10K effort, cool-down) |
| Thursday | Easy run — 6 mi |
| Friday | Easy run — 5 mi |
| Saturday | Long run — 16 mi |
| Sunday | Easy run — 5 mi |
Advanced — Week 8 of 20 · Long run: 19 mi · Weekly total: ~54 mi
| Day | Workout |
|---|---|
| Monday | Rest |
| Tuesday | Easy run — 8 mi |
| Wednesday | Intervals — 8 mi (2 mi warm-up, 5×1200m at 10K effort, cool-down) |
| Thursday | Easy run — 7 mi |
| Friday | Easy run — 6 mi |
| Saturday | Long run — 19 mi (4 mi easy, 10 mi at marathon pace, 5 mi easy) |
| Sunday | Easy run — 6 mi |
Quality workout type rotates each week (Tempo → Intervals → Marathon Pace). The specific structure is generated from your goal time — an Advanced runner targeting 3:00:00 runs tempo at a different pace than one targeting 3:30:00.
Related resources
Common marathon training mistakes — and how to avoid them
Starting the long run too fast
The long run's purpose is time on feet, not pace. Running your 18-miler at marathon pace doesn't prepare you better — it just leaves you more fatigued for the rest of the week. Your easy pace on long run days should feel almost boringly slow. That's correct.
Running easy days too hard
Most runners run their recovery days 30–60 seconds per mile too fast. Easy days exist to accumulate aerobic volume without taxing your system — if you're breathing hard, you're not running easy. Pacerly calculates your easy pace from your goal time so there's a specific number to aim for, not a vague “comfortable.”
Skipping recovery and cutback weeks
Every 3–4 weeks, Pacerly drops your weekly mileage by ~10–18% before resuming progression. These cutback weeks are not optional rest — they're when your body consolidates fitness gains from the previous block. Skipping them to chase more volume is one of the most reliable ways to end up injured.
Trying to make up missed mileage
Missed a week? Don't try to cram two weeks of mileage into one. Pick up where the plan left off, ease back in if you feel rusty, and reduce the following week slightly if needed. Your fitness doesn't disappear in 7 days — but cramming extra miles does increase injury risk substantially.
Ignoring the taper
The final 2–3 weeks of your plan reduce volume significantly. Runners who maintain or increase mileage through this window consistently arrive at the start line more fatigued than those who trust the taper. Your legs will feel different during taper — restless, a little flat. That's normal. Trust the process.
Common questions about marathon training plans
How many weeks do I need to train for a marathon?
Most runners need 16–20 weeks. Beginners benefit from the full 20 weeks — building mileage from scratch takes time, and rushing it increases injury risk. Intermediate and advanced runners with an existing base of 25–40 miles per week can prepare effectively in 16–18 weeks. If your race is more than 20 weeks away, you don't need to start formal marathon training yet — use that time to build a consistent aerobic base.
What is peak weekly mileage?
Peak mileage is the highest-volume week in your training cycle, typically reached 2–3 weeks before race day. For Beginner plans, peak week sits around 40–42 miles. Intermediate runners reach 50–55 miles; Advanced runners reach 60–65 miles. After peak week, a taper reduces volume by 30–40% so your legs arrive at the start line recovered — not fatigued.
What should my easy runs feel like?
Easy runs should feel genuinely easy — conversational pace, where you could hold a full sentence without gasping. Most runners run their easy days too fast, which bleeds into their quality sessions. Pacerly calculates your easy pace from your goal time so there's no guesswork: if the plan says 11:10/mi easy, that's the target, not a suggestion.
What if I miss a week of training?
Missing one week mid-plan is rarely catastrophic. The aerobic fitness you've built doesn't disappear in 7 days. The safest approach: pick up from where your plan left off (don't try to make up the missed mileage), and reduce the following week slightly if you feel rusty. Missing two or more consecutive weeks warrants a real assessment of whether your race date is still realistic.
How is this different from Hal Higdon or Nike Run Club plans?
Generic plans give you the same schedule regardless of your goal time. Pacerly's plan is built around your specific race date, goal time, and experience level — so every target pace in the plan is derived from your finish-time goal. Easy runs, tempo pace, marathon-pace miles — they're all calibrated to you, not a runner who happens to be training at the same time of year.
Can I follow this plan on a treadmill?
Yes. Every workout is defined by distance and effort level — treadmill or outdoor, the sessions translate directly. Treadmill runners should set a 1% incline to approximate outdoor air resistance. Long runs over 16 miles are usually easier to do outside for mental reasons, but there is no structural issue with completing them on a treadmill.
What comes after the training plan?
Knowing your weekly mileage gets you to the start line. Knowing how to pace the race gets you to the finish line in your goal time. Pacerly's race strategy engine generates a mile-by-mile execution plan based on your goal pace and how to distribute effort across 26.2 miles.
Is this plan really free?
Yes. Pacerly is free to use — no credit card required. You get the complete week-by-week schedule, all target paces, Strava sync, and weekly coaching adaptations that adjust your plan based on what you actually ran.
Ready to build your plan?
Enter your details below — your free marathon training plan is ready in seconds.
Example: 16-week plan for a 4:00:00 marathon
Why runners choose Pacerly
Built around your goal
Every workout is generated from your race date, goal time, and experience level. Not a template — a plan.
Know exactly what to run
Clear daily workouts with target paces for every run. No guesswork about how fast to go or how far.
Ready for race day
Your training plan leads directly into a personalized race strategy — a mile-by-mile pacing plan for 26.2 miles.