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AnswersHow long should a long run be?
Long enough to build endurance for your race, and never so long that it dominates the week. Race Shape caps the long run three ways: at no more than about 35% of the week's running (40% for ultras), at an absolute distance for the race — 24 km for a half marathon, 34 km for a marathon — and at the time you say you actually have. Whichever limit is lowest wins.
The absolute caps, by race
| Race | Longest run in the plan |
|---|---|
| 5 km | 12 km |
| 10 km | 16 km |
| Half marathon | 24 km |
| Marathon | 34 km |
| 50 km | 38 km |
| 56 km (Two Oceans) | 42 km |
| Longer ultras (Comrades) | 55 km |
Why the share matters
A 32 km long run in a 45 km week is most of the week in one go. It takes days to recover from, crowds out the other sessions, and is where a lot of overuse injuries start. Capping the long run as a share of the week means it grows as the week grows, rather than running ahead of it. For a runner on 40 km a week, 35% is 14 km — and the answer to wanting a longer long run is more running across the week, not a bigger Sunday.
Past about three hours, a marathon long run gives diminishing returns for the damage it does. That is why the marathon cap is 34 km rather than the full distance.
Common questions
Should I run the full marathon distance in training?
Usually not. The last few kilometres cost far more recovery than they return. Race-day adrenaline, the taper and fuelling cover the gap.
How slow should the long run be?
Mostly at easy pace. Some plans add race-pace segments in the later weeks — these come after a solid base of easy long runs.
What if I only have time at weekends?
Tell the plan how long you have. It trims the long run to fit and says so, rather than prescribing something you cannot do.
Sources
- Daniels, J. Daniels' Running Formula.