RunFast
How a half marathon training plan is built
A half marathon training plan combines weekly distance, a long run, easy and hard running, lighter weeks and a taper. The research backs some of these parts and offers no agreed recipe for combining them.
This guide splits a half marathon training plan into six parts: how far you run each week, how fast that distance grows, the long run, easy and hard running, lighter weeks and the taper. The research gives no recipe for putting them together into a training plan to run a half marathon: a 2020 review says there is no consensus on the best practice for recreational runners to train effectively.1 The same breakdown for the full distance is in how a marathon training plan is built.
What the research does support for the half itself is an association. In a 2020 cohort of 556 half-marathon participants, recreational runners who answered questionnaires, a weekly volume above 32 km (about 20 miles) and a longest run above 21 km (about 13 miles) were each associated with a faster finish time and with less slowing down in the race, and the study found no link between training characteristics and injury.2
What the research doesn’t support is a fixed weekly increase: a 2022 systematic review of 36 articles found the evidence linking injuries to weekly distance, or to changes in training, conflicting.3 The sources used here don’t test how many weeks a plan should last or how long each stage should be, and a 2020 review reports no consensus on how recreational runners should train.1 The taper and the mix of easy and hard running have guides of their own, on how long a marathon taper should be and 80/20 running and what the research says.
The parts of a plan, and what the research says about each
If you are working out how to train for a half marathon, here is what the research says about each part of a half marathon running training plan, and how sure it is. Each claim links to its source, and our editorial standards say how each one is checked.
Plan length and stages
A 2022 systematic review of ten articles on highly trained and elite middle- and long-distance runners encourages a traditional periodisation pattern on a hard day-easy day basis.4 It describes their training intensity distribution, the mix of easy and hard running, shifting from pyramidal in the preparatory and precompetitive periods towards polarised in the competitive period.4 Read it as how such runners organise a season, not as a template for yours.
A cross-sectional study of 154 recreational runners of both sexes, who answered a web survey, concluded that their training habits and periodisation characteristics differ by race distance: 10 km, half marathon, marathon and ultramarathon.5 It describes what runners do, not what works best.5
How much you run each week
The 2020 cohort questioned 556 half-marathon participants, and 441 marathon participants, about injuries, their average weekly training volume and their longest run.2 In the half-marathon runners, a weekly volume above 32 km (about 20 miles) was associated with a faster finish time, and higher volume was also related to less decline in pace, that is, less slowing down.2 No associations between training characteristics and running injuries were identified, and the authors conclude that preparing for a (half-)marathon with a relatively high volume and long runs associates with a faster finish but does not seem related to a higher injury risk.2
How fast to build
A 2022 systematic review of 36 articles found the evidence linking weekly distance, duration, frequency, intensity or changes in them with the onset of running injuries conflicting.3 It concluded that current evidence does not consistently link running injuries with specific training parameters or recent changes in them, and that caution should be taken when recommending optimal parameters or progressions.3
A 2018 systematic review, of runners aged 18 to 65, found four eligible articles, three of which linked increases in training load with a higher risk of running injury.6 It also reported no difference between a 10% and a 24% average increase in weekly volume, and concluded that very limited evidence supports a sudden change in training load being linked to injury.6
A randomised trial in 532 novice runners preparing for a 6.7 km (4-mile) event tested a graded 13-week programme based on the 10% rule.7 Injury incidence was 20.8% in the graded group and 20.3% in the standard group, and the trial showed no effect of the graded programme on injury.7
A 1-year cohort of 874 novice runners with GPS watches grouped them by how their weekly distance changed: it rose by less than 10% or fell, rose by 10% to 30%, or rose by more than 30%.8 Injury rates did not differ significantly across the three groups.8 Its authors suggest novice runners may be well advised to increase their weekly distance by less than 30% a week over a 2-week period.8
An International Olympic Committee consensus statement on load in sport says emerging evidence indicates that poor load management is a major risk factor for injury.9
The long run
In the half-marathon runners of the 2020 cohort, a longest run above 21 km (about 13 miles) was associated with a faster finish time and with less decline in pace.2 The authors conclude that long endurance runs, with a relatively high volume, associate with a faster finish time but do not seem related to a higher injury risk.2 That is a link between what runners did and how they raced, not a distance to aim for.
Easy and hard running
The review of highly trained and elite runners encourages a hard day-easy day pattern.4 For the mix in detail, see 80/20 running and what the research says, and for one of the hard sessions, the tempo run.
Lighter weeks
A consensus statement on recovery in sport says an adequate balance between stress (training and competition load, and other life demands) and recovery is essential for athletes to achieve continuous high-level performance.10 In a plan, build in easier weeks or days at a rhythm that lets you recover.
The taper
A meta-analysis of competitive athletes found a 2-week taper with volume cut by 41–60% seemed the most efficient strategy, without any change in training intensity or frequency.11 A 2023 meta-analysis of endurance athletes found a taper of up to 21 days with the same cut, and intensity and frequency unchanged, effective; neither reports results for half-marathon runners.12, 11 The guide to how long a marathon taper should be has the detail, written for marathons.
How to apply it
This guide doesn’t give a dated half marathon training schedule. Instead, the first table gives you checks, part by part, for any half plan, whether it is a half marathon training plan for beginners or one for your tenth race, and whether it came from a book, a coach, an app or your own notes.
| Part | What to look for | What the evidence says |
|---|---|---|
| Plan length | A length that fits your race date and lets you build steadily from where you are | The sources used here don’t test it, and a 2020 review reports no consensus on the best way for recreational runners to train1 |
| Weekly distance | A start near what you run now, then a build to the plan’s biggest weeks | In half-marathon participants, above 32 km a week went with faster finishes, and across the whole study, half and full, training volume wasn’t linked to injury2 |
| How fast it builds | Steady rises, with no sudden big jump from one week to the next | Two systematic reviews found the evidence linking changes in training to injury conflicting or very limited3, 6 |
| The long run | A long run that grows over the weeks | In half-marathon participants, a longest run above 21 km went with faster finishes, and across the study’s half and full marathon runners, long runs did not seem related to a higher injury risk2 |
| Hard and easy days | Hard sessions with easier days between them | A systematic review of highly trained and elite runners encourages a hard day-easy day pattern4 |
| Lighter weeks | Easier weeks or days built in, at a rhythm that lets you recover | A consensus statement calls a balance between stress and recovery essential for athletes10 |
| The taper | A spell of falling volume before the race, keeping your faster running and your running days | In competitive and endurance athletes, two meta-analyses found volume cuts of 41–60% over 2 weeks, or up to 21 days, effective with intensity and frequency unchanged11, 12 |
A fixed weekly percentage also compounds. The second table shows what your starting weekly distance is multiplied by after 4, 8, 12 and 14 weeks of rising by the same percentage every week.
| Weekly increase | 4 weeks | 8 weeks | 12 weeks | 14 weeks |
|---|---|---|---|---|
| 6% | 1.26 | 1.59 | 2.01 | 2.26 |
| 8% | 1.36 | 1.85 | 2.52 | 2.94 |
| 10% | 1.46 | 2.14 | 3.14 | 3.80 |
At 10% a week for 14 weeks, 20 km (about 12 miles) a week would become about 76 km (about 47 miles). So no plan can keep adding distance every week to the end: look for a rise that levels off, with easier weeks along the way.
To set the pace of each kind of run, work out your training paces from a recent race with the pace calculator. For race-day splits, see the half marathon pace chart.
In RunFast
RunFast writes a half marathon plan back from your race date, building its training weeks around the days you can train, from 3 to 6 a week. Onboarding asks for your current weekly distance, your longest recent run, your available training days and your goal, and compares the weeks until your race with a recommended minimum of 10 weeks for a half marathon, a design choice rather than a trial result. A race plan lasts 3 to 30 weeks and runs base, build, peak and taper into race day, and a half marathon plan of four weeks or more tapers for two, race week included. Race week is set by the race date: rest days, a short easy run four days before the race and a short primer with strides two days before. Weekly distance starts from your current figure, never below 6 km, and rises 6% a week for beginners, 8% for novices, 9% for intermediate runners and 10% for advanced ones, up to a peak capped by your level and starting distance. Every fourth week of the build is a lighter week at about 75% of the week before, unless it is the last build week. That weekly rise, that lighter-week rhythm and the taper’s length are RunFast’s design choices, not results from a trial. One long run a week, at easy pace and on the weekend where your days allow, starts from your longest recent run (or 30% of your weekly distance, if that is more) and grows towards a cap of 22 km (about 13.7 miles) for a half marathon, never more than 45% of the week’s distance. Up to two quality sessions a week, a tempo run at threshold pace or intervals of 1,000 m repetitions, depend on stage and level, and the other days are easy runs, with very easy shakeouts after a hard day. Training paces come from Daniels’ VDOT model, worked out from a recent race or your fitness level.
Where the evidence is thin or mixed
One cohort for the half
The half-marathon findings come from one cohort of recreational runners, who reported their training in questionnaires.2 Its abstract gives the effects without units and doesn’t name the groups that runners above 32 km a week, or with a longest run above 21 km, were compared with, so this guide gives no minutes saved and no target.2 The injury finding covers the whole study, which also included 441 marathon participants, and one cohort that finds no link is not proof that more running is safe.2 In practice, read the 32 km and 21 km figures as a direction, not a line to cross.
No fixed weekly increase is proven
The randomised trial of the 10% rule was in novice runners preparing for a 6.7 km event, not a half marathon, and it tested a whole 13-week programme built on the rule rather than the 10% figure alone.7 The cohort that compared rates of increase followed novice runners with GPS watches who were training on their own, and its authors’ advice, under 30% a week over 2 weeks, is hedged and comes from that one cohort.8 Of the two systematic reviews, the 2022 one, of 36 articles, called the evidence conflicting, and the 2018 one, of four, called the evidence on sudden changes very limited.3, 6 The International Olympic Committee statement supports the broader point, that poor load management is a major risk factor for injury, but it is framed around elite sport and calls that evidence emerging.9 In practice, treat a fixed weekly percentage as a rule of thumb rather than a tested limit.
Convention, not tests
The 2020 review says there is no consensus on the best practice for recreational runners to train effectively.1 The periodisation review drew on ten articles about highly trained and elite runners.4 The recovery consensus calls for a balance of stress and recovery in athletes without setting how often a lighter week should come.10 The taper meta-analyses studied competitive and endurance athletes, and neither was a study of recreational half-marathon runners.11, 12 The sources used here don’t test how many weeks a half marathon plan should last, how long each stage should be, how often a lighter week should come, or how long a half-marathon runner’s taper should be.1, 10, 11, 12 Choose a length that fits your race date and lets you build steadily from where you are.
Associations, and who was studied
The half-marathon cohort and the survey of 154 recreational runners both rested on what runners reported themselves, so they show what went with faster times, or what runners do, not what caused anything.2, 5 The periodisation review was of highly trained and elite middle- and long-distance runners.4 Of the injury studies, the trial and the GPS-watch cohort were in novice runners.7, 8 The taper meta-analyses were in competitive athletes and in endurance athletes.11, 12 In practice, use the numbers for direction and scale, not as targets.
Common questions
How many weeks should a half marathon training plan last?
The research used here doesn’t give a number: a 2020 review says there is no consensus on the best practice for recreational runners to train effectively, and the sources used here don’t test plan length.1 So nothing here says a 12-week half marathon training plan is better than an 8-, 10- or 16-week one. Choose a length that fits your race date and lets you build steadily from where you are.
How long should the longest run be?
In 556 half-marathon participants, a longest run above 21 km (about 13 miles) was associated with a faster finish time and less slowing down, and across the study’s half and full marathon runners, long runs did not seem related to a higher injury risk.2 The abstract doesn’t say what those runners were compared with, so take it as a reason to build your long run over the weeks, not as proof that you need to run the full distance before race day.2
Is the 10% rule right for a half marathon plan?
Not as a tested rule: in a randomised trial of 532 novice runners preparing for a 6.7 km event, a 13-week programme based on the 10% rule had no effect on injuries.7 One systematic review found the evidence linking changes in training to injury conflicting, and another reported no difference between 10% and 24% average weekly increases.3, 6 Rather than fixing on 10%, keep your rises steady and avoid big jumps.
How long should the taper be?
In competitive athletes, a meta-analysis found a 2-week taper with volume cut by 41–60% seemed the most efficient strategy, and in endurance athletes another found a taper of up to 21 days effective, both with intensity and frequency unchanged.11, 12 Neither reports results for half-marathon runners, so treat about two weeks as a starting point, not a tested figure for the half.11, 12
This guide is general information, not medical advice. If you have an injury, a health condition or are pregnant, ask a doctor or physiotherapist before changing how you train or eat.
Related guides
- How a marathon training plan is builtA marathon training plan combines rising weekly distance, a long run, easy and hard running, lighter weeks and a taper. The research backs some of these parts and says little about how to combine them.
- Half marathon pace chart: pace and splits for your goal timeFind your goal time for the even pace and splits to run it, per kilometre and per mile, then see what the research says about holding that pace over a half marathon.
- 80/20 running: what the research says80/20 running means keeping most training easy. A 2024 meta-analysis found a small VO2peak advantage for polarised training, but small studies in recreational runners found no significant difference in performance.
Sources
- Boullosa D, Esteve-Lanao J, Casado A, Peyré-Tartaruga LA, Gomes da Rosa R, Del Coso J. Factors Affecting Training and Physical Performance in Recreational Endurance Runners. Sports. 2020. doi:10.3390/sports8030035
- Fokkema T, van Damme AADN, Fornerod MWJ, de Vos RJ, Bierma-Zeinstra SMA, van Middelkoop M. Training for a (half-)marathon: Training volume and longest endurance run related to performance and running injuries. Scandinavian Journal of Medicine & Science in Sports. 2020. doi:10.1111/sms.13725
- Fredette A, Roy JS, Perreault K, Dupuis F, Napier C, Esculier JF. The Association Between Running Injuries and Training Parameters: A Systematic Review. Journal of Athletic Training. 2022. doi:10.4085/1062-6050-0195.21
- Casado A, González-Mohíno F, González-Ravé JM, Foster C. Training Periodization, Methods, Intensity Distribution, and Volume in Highly Trained and Elite Distance Runners: A Systematic Review. International Journal of Sports Physiology and Performance. 2022. doi:10.1123/ijspp.2021-0435
- Knechtle B, Tanous D, Thuany M, Motevalli M, Wirnitzer G, Leitzmann C, Weiss K, Rosemann T, Wirnitzer K. Differences in training characteristics of recreational endurance runners by race distance: results from the NURMI Study (Step 2). Frontiers in Psychology. 2023. doi:10.3389/fpsyg.2023.1269374
- Damsted C, Glad S, Nielsen RO, Sørensen H, Malisoux L. Is There Evidence for an Association Between Changes in Training Load and Running-Related Injuries? A Systematic Review. International Journal of Sports Physical Therapy. 2018. doi:10.26603/ijspt20180931
- Buist I, Bredeweg SW, van Mechelen W, Lemmink KA, Pepping GJ, Diercks RL. No effect of a graded training program on the number of running-related injuries in novice runners: a randomized controlled trial. The American Journal of Sports Medicine. 2008. doi:10.1177/0363546507307505
- Nielsen RØ, Parner ET, Nohr EA, Sørensen H, Lind M, Rasmussen S. Excessive progression in weekly running distance and risk of running-related injuries: an association which varies according to type of injury. Journal of Orthopaedic & Sports Physical Therapy. 2014. doi:10.2519/jospt.2014.5164
- Soligard T, Schwellnus M, Alonso JM, Bahr R, Clarsen B, Dijkstra HP, Gabbett T, Gleeson M, Hägglund M, Hutchinson MR, Janse van Rensburg C, Khan KM, Meeusen R, Orchard JW, Pluim BM, Raftery M, Budgett R, Engebretsen L. How much is too much? (Part 1) International Olympic Committee consensus statement on load in sport and risk of injury. British Journal of Sports Medicine. 2016. doi:10.1136/bjsports-2016-096581
- Kellmann M, Bertollo M, Bosquet L, Brink M, Coutts AJ, Duffield R, Erlacher D, Halson SL, Hecksteden A, Heidari J, Kallus KW, Meeusen R, Mujika I, Robazza C, Skorski S, Venter R, Beckmann J. Recovery and Performance in Sport: Consensus Statement. International Journal of Sports Physiology and Performance. 2018. doi:10.1123/ijspp.2017-0759
- Bosquet L, Montpetit J, Arvisais D, Mujika I. Effects of tapering on performance: a meta-analysis. Medicine and Science in Sports and Exercise. 2007. doi:10.1249/mss.0b013e31806010e0
- Wang Z, Wang YT, Gao W, Zhong Y. Effects of tapering on performance in endurance athletes: A systematic review and meta-analysis. PLOS ONE. 2023. doi:10.1371/journal.pone.0282838