Tokyo Marathon Training Plan
Train for the Tokyo Marathon: a cool March race from Shinjuku to Tokyo Station, with a fast downhill start and a flat course that rewards even pacing.
The plan, week by week
Minutes per week. Tap a week.Training specifically for the Tokyo Marathon: a plan that accounts for the course profile, typical weather conditions, and the race-specific fitness that separates prepared runners from generic marathon fitness. 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.
From Shinjuku to Tokyo Station
The Tokyo Marathon starts outside the Tokyo Metropolitan Government Building in Shinjuku and finishes near Tokyo Station. The opening kilometres run downhill off the Shinjuku plateau, and after that the course is mostly flat, looping east past Asakusa and south towards Shinagawa before heading back through the centre. The few rises come late, over bridges and overpasses, when your legs notice them most. It is one of the six World Marathon Majors, and a fast course for anyone who paces the start well.
The downhill start is the trap
A crowded start on a downhill road makes goal pace feel effortless, and the kilometres you bank there are paid back after 30 km. Run the first 5 km at or slightly slower than goal pace, even if the splits look too slow, and let the flat middle of the race do its work. In training, practise this on long runs: start them deliberately easy, and finish the last few kilometres at marathon effort, so holding back early becomes a habit rather than a decision on the day.
Training for an early March race
Tokyo is run in early March, so the heart of your training falls in December, January and February. For most runners in the northern hemisphere that means cold, dark training, with Christmas in the middle of the build. Plan your biggest weeks around the holidays rather than through them, and keep one long run a week as the fixed point. Race morning in Tokyo is usually cool, which suits marathon running: dress for the start in an old layer you are happy to leave behind before the gun.
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.