Marathon interval workouts, tempo runs and long runs
Marathon interval workouts, tempo runs and the weekly long run are the three sessions that decide your race. The long run matters most: it peaks at 18 to 20 miles about three weeks before the race. This page covers how far, how fast and when for each. The generator schedules them around your run days.
The three marathon workouts
Everything else in a marathon plan is easy running. These three sessions carry the training effect, and the plan places each one on a fixed day so they never land back to back.
| Session | What it is | Pace in the plan | When |
|---|---|---|---|
| Long run | One steady run a week, 12 to 20 miles in the peak phase | Race pace plus 60 seconds per mile, conversational | Every week, Sunday by default |
| Tempo run | 1 mile easy, the middle miles comfortably hard, 1 mile easy | Race pace minus 20 seconds per mile | Once a week in build and peak, runners who have raced the distance before |
| Intervals | Repeats of 800 m to a mile with a jog between | Race pace minus 45 seconds per mile | Optional; the generator's marathon plans use the tempo run instead |
For a 4:00 goal the generator sets race pace at 9:09 per mile, easy runs at 10:24, the long run at 10:09 and tempo at 8:49. Enter your own goal and the paces recompute; the 4 hour marathon pace page shows where 9:09 comes from.
Build your free marathon plan
Same engine as every plan on this site, but with your race date, your run days and your longest recent run. Prints to PDF, exports to your calendar. No signup.
Longest run before a marathon: how long and when
Eighteen to 20 miles, three weeks before the race. The generator caps the long run at 20 miles because the extra miles past that point cost more recovery than they return in fitness. Nobody runs 26.2 in training: the taper and the race-day crowd carry the last six miles. If you run slower than about 12 minutes per mile, cap the session by time instead, at around three and a half hours.
In the engine the long run is set to reach its 20-mile cap in the last week before the taper. Enter 30 miles a week and a 12-mile longest run, and the 18-week plan runs 18.3 miles in week 14 and 20 in week 15, three weeks out. Growth per week is solved from your longest recent run and clamped between 4 and 20 percent, with a drop to 85 percent on cutback weeks.
The last long run before a marathon
The final long run is the one three weeks out. It doubles as the dress rehearsal: race shoes, race breakfast, race gels, race start time. Runners who have done the distance before finish it with the last 4 to 6 miles at goal pace; first-timers keep it easy throughout. After that the taper takes over, and the Sunday runs shrink to about 14, 9 and 5 miles in the three weeks after a 20-miler.
A 20-miler two weeks out is too close; the legs need three weeks to absorb it.
Marathon interval workouts and tempo runs
The tempo run is the marathon workout that matters. The plan's version is simple: a mile easy, the middle miles at tempo, a mile easy. The middle grows from 3 miles to 6 or more through the build and peak phases. Comfortably hard is the test: you can speak in short sentences, not paragraphs. The session goes mid-week, Wednesday by default, never the day before or after the long run, and only in plans with four or more run days.
Marathon interval workouts are for runners who already have the tempo habit. Six repeats of 800 meters or four of a mile, with a slow jog between, at 45 seconds per mile under race pace, make marathon pace feel controlled. The generator schedules intervals in 5K and 10K plans and gives marathon plans the tempo. If you want intervals, swap them in on the tempo day rather than adding a third hard session.
Long run strategies for the marathon
Most Sunday runs are plain: start easy, stay easy, finish wanting one more mile. Two variations earn a place in the peak phase for experienced runners, once a fortnight at most. A progression run finishes the last third at race pace. A fast-finish run holds easy pace until the last 3 to 4 miles, then runs them at goal pace. Fueling practice belongs on every run over 90 minutes; see marathon fueling. The weekly totals around these sessions are in marathon weekly mileage, and the marathon pace chart gives the goal pace they are built around.
Frequently asked questions
How long before a marathon should your longest run be?
Three weeks before the race. Two weeks is too close to recover; four weeks leaves a long gap. The generator places it in the last peak week before the taper.
How long should the last long run before a marathon be?
18 to 20 miles, or about three and a half hours for slower runners. The plan caps it at 20 miles.
How far should the weekly long run be during marathon training?
It grows from your longest recent run toward the 20-mile cap, between 4 and 20 percent a week depending on how far it has to go, drops on every fourth week, and reaches 18 to 20 miles in the last weeks before the taper. Early in the plan 8 to 12 miles is normal.
Do I need interval workouts for a marathon?
No. A weekly tempo run and the long run are enough for most goals. Intervals help experienced runners sharpen, but they replace the tempo day rather than add to it.
Should the long run be at race pace?
Mostly no. The plan sets it 60 seconds per mile slower than race pace. Experienced runners can finish the last few miles of a late-plan long run at goal pace.