SKILL/TREE

A marathon plan built around your actual starting point.

Tell it your current weekly mileage, longest recent long run, goal finish, and weeks-to-race. Get a week-by-week plan with easy/tempo/MP paces, a 3-week taper, and a mile-by-mile fueling protocol.

$3.99
Works in Claude (Pro/Max/Team) or ChatGPT (Plus/Team) · paid AI plan required
Both Claude + ChatGPT packages included — you can't pick the wrong one.
Updated
Included
01Outputs a complete 12-20 week plan with every run labeled: easy, tempo, MP miles, long run, with exact pace ranges.
02Scales to your real base — 25 mpw with an 11-mile long run gets a different block than 45 mpw with 16 miles.
03Supports 3-day, 4-day, 5-day, and 6-day training weeks. Pick what fits the rest of your life.
04Includes a 3-week marathon taper (or 2-week half taper) so you don't show up to the start line cooked.
05Race-day fueling plan: carb-loading window, race-morning meal, gel schedule by mile, electrolytes, heat adjustments.
06Refuses to produce dangerous plans — 8 weeks with a 7-mile long run won't get you a marathon block, it'll get you a half plan and an honest conversation.

What it does

A marathon training plan generator for recreational runners that takes your real starting point — current weekly mileage, longest recent long run, goal finish time, and weeks to race — and produces a periodized 12-20 week plan grounded in Daniels, Pfitzinger, and Higdon frameworks. Not a generic template with your name pasted on top. It back-calculates pace targets from your goal finish (easy, long run, tempo, threshold, MP, strides), builds a week-by-week table with cutback weeks every 3rd-4th week, caps peak mileage at base × 1.4 to keep injury risk sane, and includes a full taper protocol. The output is a printable HTML artifact: pace table at top, color-coded weekly grid, race-day pacing card you can pin to your shirt, and a fueling protocol card covering carb loading, race-morning meal, in-race gel timing, and electrolytes. It will refuse to write an 8-week first marathon plan off a 15 mpw base — and offer you a half marathon plan or a walk-run finisher guide instead.

Frequently asked

How many weeks do I need to train for my first marathon safely?
12 weeks is the floor and only if you already have a 14-mile long run and 35 mpw base. 16-20 weeks is more realistic for a first marathon. The plan will tell you honestly when your inputs don't support the timeline and offer alternatives (compressed half plan, base-building phase, walk-run finisher).
Can I just use a free Hal Higdon plan instead of paying for this?
You can. Generic plans work — but they assume one starting point. This plan scales to your actual mileage, your actual long run, your actual goal time, and your actual available days per week. It also includes the race-day pacing card and fueling protocol most free plans skip.
What if my goal time isn't realistic?
It'll tell you. The plan applies a reality check using Riegel from any recent race time you share. If your goal requires >15% faster than current fitness supports, it sets the plan at a realistic intermediate target and describes what a stretch goal would actually require.
Does it handle half marathon plans too?
Yes — 8-12 week half marathon plans with appropriate 2-week taper, half-specific fueling (1-3 gels instead of 5-6), and pace targets back-calculated from your half goal time.
Does this work in Claude or ChatGPT?
This is a Claude skill — it runs inside Claude.ai. You'll need a Claude account to load it.

Install — no Terminal required

After checkout you land on a page with a one-click download and a pre-built install prompt. Pick the AI you already pay for — both packages are included, so you can't pick wrong.

What you'll see the second your payment clears
Your license key
ST-XXXX-XXXX-XXXX · permanent
Pre-built install prompt⧉ Copy
ChatGPT package (ZIP)⬇ Download

No setup work before you buy — copy, paste, done.

Have Claude Pro, Max, or Team?
Copy the prompt, paste into Claude

Copy the pre-built install prompt from the success page, paste it into any Claude Code chat, and Claude installs the skill itself — about 10 seconds. Using the app instead? Drop the downloaded folder into a Claude Project's knowledge and ask Claude to use it.

Have ChatGPT Plus or Team?
Build a Custom GPT — ~2 minutes
  1. Click Download ChatGPT package (included with every purchase).
  2. Unzip it — inside is a SETUP.md and a knowledge/ folder.
  3. Go to chatgpt.com → your profile → My GPTs → Create a GPT → Configure.
  4. Paste the Name, Description, and Instructions from SETUP.md into the matching fields.
  5. Under Knowledge, upload every file in the knowledge/ folder.
  6. Click Create/Save, open your GPT, and describe your task in plain English.

A paid plan on either platform is required — Claude (Pro, Max, or Team) or ChatGPT (Plus or Team). Comfortable with Terminal? A one-line npx skilltree-network install path is available too.

More in Fitness & Race

View all Fitness & Race skills →
Fitness & Race

Wendler 5/3/1 Cycle Generator

Plug in your training maxes — get a full Wendler 5/3/1 cycle with weights, assistance work, plates-per-side, and a log sheet.

Wendler 5/3/1 cycle generator with assistance template
$3.99
Fitness & Race

Couch to 5K Personalized Training Plan

Personal 8-10 week couch-to-5K plan with walk/run intervals, RPE pace targets, rest days, and race-day strategy.

Couch-to-5K personalized 8-week plan
$3.99
Fitness & Race

Hyrox 12-Week Training Plan Generator

5k time + station PRs + goal finish in, periodized 12-week Hyrox plan with per-station race-day pacing chart out.

Hyrox 12-week training plan generator
$3.99
Fitness & Race

Hyrox Race Day Pacing Strategist

Goal time + 8 station splits in, color-coded race-day pacing card with per-station targets and 3 push / 3 conserve calls out.

Hyrox race-day pacing strategy
$3.99