Training Plan for Your First Marathon
Everything you need to run your first marathon: an 18-week plan, fuelling guide, long run strategy, and an AI coach who has seen every first-timer fear.
The plan, week by week
Minutes per week. Tap a week.Every version of this plan
The chart above is the one marked “shown”. Ask Claude for any of these and it builds that one, paced from your own runs.
| Version |
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| Your first marathon (shown) |
| Beginners |
The marathon is fundamentally an aerobic event with a metabolic ceiling problem. Running out of glycogen — 'the wall' — is a fuelling and pacing failure, not a fitness failure. The training goal is to build a large enough aerobic base, develop fat oxidation efficiency, and practice race-pace running so the body knows what's coming on race day. This plan is built around what you're actually trying to accomplish — with the structure, sessions, and weekly adaptation to get you there.
The single biggest mistake first-time marathoners make
Running the long run too fast. The long run in marathon training is an aerobic development tool, not a race simulation. It should be run 60–90 seconds per kilometre slower than goal marathon pace — slow enough that finishing it doesn't require significant recovery time. First-time marathoners who push long runs at effort pace arrive at the start line with accumulated fatigue rather than accumulated fitness.
Fuelling your first marathon
The marathon is the only common road race that requires mid-race fuelling. Practise taking on gels, chews, or drinks during long runs — not just once, but every long run of 16 miles or more. On race day, take something every 45–60 minutes from the gun regardless of how you feel. By the time you feel like you need fuel, you're already behind.
The emotional journey of 26.2
Most first-time marathoners experience a profound low somewhere between miles 18 and 22. Legs feel dead, goal time looks impossible, and the finish feels abstract. This is the wall, and it's almost always a combination of fatigue and pacing error. If you've run conservatively, it often passes. The runners who get through it are those who've been told it's coming and have a plan: slow down, take fuel, and run to the next landmark rather than the finish.
Why easy days are your most important sessions
The most counterintuitive thing about starting to run: your easy days are doing more work than you think. Slow aerobic running builds the mitochondrial density, capillary networks, and musculotendinous resilience that form the foundation everything else rests on. Running every session at moderate effort — which feels productive — actually blunts adaptation and raises injury risk. Keep easy days genuinely easy.
The 10% rule and when to break it
The classic guidance is to never increase weekly mileage by more than 10% from one week to the next. It's a useful heuristic, but not sacred. The more important signal is how your body responds: persistent soreness, disrupted sleep, elevated resting heart rate, and loss of motivation are early warning signs that load is outpacing recovery. When in doubt, do less.
What to do when you miss a session
Missing sessions is part of training, not a failure. The worst response is to try to 'make up' a missed run by cramming it into an already-full week — that's how injuries start. If you miss a day, adjust the rest of the week and protect your long run. With Daash, tell Claude what happened and it reworks the rest of the week on your watch, so you never need to guess how to recover.
Questions
How many days per week does this marathon plan require?
Most sessions in this plan run four to five days per week, including one quality session, a long run, and easy aerobic running. The plan is designed to be adjustable — with Daash, Claude can restructure it around your available days each week.
Do I need a GPS watch to follow this marathon training plan?
A GPS watch or running app is helpful for tracking pace and distance, but not strictly required. Effort-based running (using a scale of 1–10 perceived exertion) works well for easy runs. For quality sessions where specific paces matter, a watch becomes more valuable.
What should I eat before a long run?
For runs under 60–75 minutes, eating beforehand is optional. For longer runs, a light carbohydrate-based meal two to three hours before the session — oats, toast with banana, or a rice-based option — provides fuel without gastrointestinal issues. Avoid high-fat, high-fibre, or unfamiliar foods on long run mornings.
How does Daash adapt the plan if I miss a session?
Daash sees missed sessions in your Garmin data. Tell Claude why — illness, fatigue, life — and it reworks the coming week: redistributing sessions, reducing volume if needed, or adjusting the next quality session, then updates the workouts on your watch.
Do I need to take gels or nutrition during training for a marathon?
For any long run over 90 minutes, practising race nutrition is valuable. Train with the gels, chews, or drinks available at your target race so your gut is adapted before race day. Do not try a new nutrition product for the first time on race morning.