What a half marathon needs
The half is a threshold race: most runners hold a pace just below their lactate threshold for 90 minutes to two hours. So the backbone is threshold work in every form, cruise intervals, tempo runs, broken tempos and progression runs, capped at ten percent of the week.
Peak weeks add reps at your half-marathon pace, three km at a time, and a 10 km race-pace run as the landmark session three weeks out. Long runs alternate between a marathon-pace finish and a progressive finish.
Weeks and days
Ten weeks minimum, twelve by default. Long runs grow to 22 km. On four days you get two quality sessions, one easy run and the long run; five or six days add the easy volume that carries a half.
The taper
One week at about half volume: a short race-pace sharpener mid-week, a shakeout the day before, race day. Keep the intensity, drop the volume.
Sample plans by level
How it works
- 1Pick your race date or week count. Enter the race date and the plan counts back to next Monday, or choose the number of weeks. The half marathon default is 12 weeks.
- 2Choose your running days. Three to six days per week and the day you want your long run. The plan spaces the hard days so they never touch.
- 3Enter a recent race. Any distance from 1500 m to the marathon. It sets your VDOT and every training pace. No recent race? Pick a level and run the week-1 time trial.
- 4Get the plan and the PDF. Every week, every session with paces, purpose and distance. Download the PDF, copy the link, or come back after a retest to refresh the paces.
Frequently asked questions
How are the training paces set?
From your recent race with Jack Daniels' VDOT equations: the same maths as the VDOT calculator on this site. Easy, marathon, threshold, interval and repetition paces all follow from one result. The plan trains you at your current fitness, not at your goal, because that is what your body can absorb today.
I have no recent race. Can I still get a plan?
Yes. Pick beginner, intermediate, advanced or sub-elite and the plan schedules a 5k time trial in week 1. Enter the time on the plan page and every pace appears. Until then sessions are shown by duration and effort.
Why is so much of the plan easy running?
Because that is what the evidence shows works. Elite and recreational data alike point to roughly 80 percent of running at low intensity, with the remaining hard sessions done properly hard. The plan reports its own easy, moderate and hard split so you can see it.
What if I miss a week?
Skip it and carry on with the plan as scheduled. Never cram two weeks into one. If you miss two weeks or more, restart at the week you left with one easier week first.
Why marathon pace in a half marathon plan?
Marathon pace is a controlled, sustainable effort that teaches you to run steadily when tired, and it is easier to recover from than half-marathon pace. The long-run finishes use it; the mid-week reps use your actual half-marathon pace.
How long should the longest run be?
About 35 percent of the week, capped at 22 km. Most runners peak at 18 to 22 km three weeks before the race. Runs over 90 minutes carry a fuelling reminder.
Sources
- Daniels J. Daniels' Running Formula, 3rd ed. Human Kinetics, 2014. Training paces, quality caps, phase model.
- Pfitzinger P, Douglas S. Advanced Marathoning, 3rd ed. Human Kinetics, 2020. Mesocycles, long-run share, marathon-pace runs.
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- Nielsen RØ, et al. Excessive progression in weekly running distance and risk of running-related injuries. J Orthop Sports Phys Ther 2014;44(10):739-747.
Last updated 6 September 2026.