Preparing a Marathon — Plan Length, Volume, Long Runs, Marathon Pace and Taper

A marathon is decided by four things: how much oxygen the runner can use, what fraction of it they can hold for two to five hours, how little energy each stride costs, and how well the legs and the fuel supply hold up in the last ten kilometres. The first three are the qualities any distance runner trains. The fourth is what makes the marathon its own event, and it is what a marathon plan adds to general endurance training: long runs, marathon pace run on tired legs, and rehearsal of the fuelling the race will need.

This document describes how a marathon preparation is built — how long it lasts, how much running it contains, how the long run and marathon-pace work progress, and how it ends on race day. It complements the general endurance document, which covers zones, polarized training and strength for runners.

What the Marathon Demands

Pace sits between the two thresholds

Most of a marathon is run at about 75–85% of VO2max. Marathon pace sits just above the first lactate threshold — the point where lactate starts to rise — and clearly below the second threshold and critical speed. Recreational runners race at about 85% of their critical speed on average: around 93% for runners finishing in 2:30, and under 80% for those out for six hours. It is therefore not a "tempo" effort. A true threshold run is faster, and a runner who trains marathon pace at threshold effort will start the race too fast: runners who covered the first half above about 94% of their critical speed slowed by more than a quarter in the second half.

Glycogen, not oxygen, is the usual limit

At marathon pace the body burns mostly carbohydrate. Stored glycogen alone is not enough to finish at that pace, which is why runners who neither train their aerobic base nor take carbohydrate during the race slow sharply in the last third. Long runs, mostly easy volume and in-race carbohydrate are the three tools against it.

Durability decides the last ten kilometres

Running economy worsens as the race goes on: the same pace costs more energy at 35 km than at 10 km. Runners who hold their economy under fatigue lose less pace late. Volume, long runs, marathon-pace segments placed late in long runs and strength training all build it.

Before the Block: Readiness and Length

Readiness for a first marathon

A marathon-specific block should start from a base, not create one:

• Weekly volume. First-time marathoners who ran under about 30 km a week in their preparation had roughly twice the injury risk of those running 30–60 km; above 60 km there was no further benefit for injury. Thirty kilometres a week is a sensible floor before the specific block.
• A half marathon first. First-timers who had already run a half marathon had well under half the odds of a major injury in their marathon preparation.
• Frequency. In a large cohort of first-time marathoners, four or more runs a week went with somewhat more injuries than fewer. For a first marathon, three or four runs a week is enough; experienced runners use five or more.
• The long run. Several months of consistent running with a long run of about 60–90 minutes completed easily. Below that, a general base phase comes first: frequency, then duration, then intensity.

How long the preparation lasts

Situation	Typical length
First marathon, from a 10K–half-marathon base	16–20 weeks
Experienced marathoner with a current base	12–16 weeks
Low current volume, returning after a break, or 50+	18–24 weeks

The plan is built backwards from race day: the taper ends on the race, the specific phase sits before the taper, and the general base fills whatever time is left. A plan whose last week is not race week is not a marathon plan — if the program would finish weeks before the race, the base phase is extended rather than finishing early.

Weekly Volume

Weekly volume is the training variable most consistently linked to marathon time, together with the average training pace, the number of runs a week and the number of long runs of 30 km or more. Runners above about 65 km a week finished around 14 minutes faster than those at 40–65 km, and runners under 40 km a week were slower still — with no increase in injuries at the higher volumes.

What runners actually do

In a large dataset of logged marathon preparations, the average over the 16 weeks before the race was about 45 km a week, for a finish of about 3:50. Runners finishing in 4:30–5:00 averaged about 35 km a week; the fastest amateurs ran well over 100 km. The extra volume of faster runners was almost all easy running.

Typical peak weekly volume by goal

Goal	Peak km per week	Roughly, hours per week
Finish a first marathon	35–50	4–5.5
4:00–4:30	45–60	5–6.5
3:30–4:00	55–75	5.5–7
3:00–3:30	70–95	6.5–8.5
Sub-3:00	85–120	7–10

These are coaching-practice peaks reached three to five weeks before the race, consistent with the averages above; they are not starting points. A runner begins from their own recent volume, measured over the weeks they actually ran, and builds toward the peak.

Progression

• Sudden spikes are what raise injury risk. In marathon runners, every day on which the last seven days' running reached 1.5 times the weekly average of the previous four weeks raised the odds of an injury; weekly jumps of 20% or more raised short-term injury risk in half-marathon preparation.
• Building about 10% per week between loading weeks keeps changes well below those levels. The 10% rule itself has not been shown to prevent injuries; it is a ceiling, not a target.
• Every third or fourth week is lighter, cutting volume by 20–30%, and keeps a shorter long run.
• After a lighter week, resume at about the level of the last loading week, not two steps above it.
• Hold the peak for two to three weeks before the taper rather than peaking for a single week.
• A runner whose recent volume is already near the peak for their goal does not need to climb further: the block shifts its effort to marathon-pace work and long-run quality.

The Long Run

The long run builds durability, fat oxidation and glycogen storage, it is where in-race fuelling is rehearsed, and it teaches the runner what the late race feels like.

How long

• No trial has set the right length, but the associations are strong: runners whose longest run was under 25 km finished about 13 minutes slower than those who reached 30–35 km, and more runs of 32 km or more went with faster times. First-timers with a longer longest run also had fewer race-day injuries.
• Coaching practice caps the long run by time as well as distance, at about 2:30–3:00, because the recovery cost rises steeply beyond it. A runner who needs 3:30 for 32 km stops shorter rather than running the distance.
• Intermediate and advanced runners typically peak at 30–35 km; first-timers at 28–32 km or the three-hour mark, whichever comes first.
• The long run is normally 25–35% of weekly volume; for runners on three or four days a week it is a larger share, which is one more reason to cap it by time.

How it progresses

• Add roughly 10–15 minutes (or 2–3 km) every week or two, and shorten it in lighter weeks rather than dropping it.
• The longest runs fall five to three weeks before the race; the last of 28–32 km or about 2:30 is three weeks out.
• Keep the day before and the day after easy, and heavy lower-body strength work at least 48 hours away from it.

Marathon-pace long runs

Elite marathoners run only a small share of their weekly kilometres — a few percent — at marathon pace; most is slower and the rest faster. Marathon pace is therefore concentrated in the last eight to ten weeks before the taper, usually in the second half of long runs, so the pace is run on tired legs:

Weeks before the race	Example
10–8	24–26 km with 2 × 4–5 km at marathon pace
7–5	26–30 km with the last 8–12 km at marathon pace
4–3	28–32 km with 12–16 km at marathon pace, or a steady long run

Alternate them with easy long runs: a marathon-pace long run costs more recovery, and marathon pace in every long run is a common way to arrive at the race tired.

Intensity and Key Sessions

Distribution

Most of the volume stays easy, at a conversational effort. Among marathoners of all levels, more time at low intensity went with faster finishes and more time at high intensity with slower ones; the fastest runners were overwhelmingly pyramidal — after easy running, the largest share is threshold and marathon-pace work, with only a little VO2max-type running. Trials in recreational and sub-elite runners favour mostly-easy distributions over threshold-heavy ones.

The sessions, phase by phase

Phase	Share of the block	Quality work
Base	first third	Easy runs, long run, strides or short hill sprints once or twice a week; one tempo or threshold session of 20–30 minutes
Build	middle third	Threshold work (tempo 20–40 min, or 3–5 × 8–10 min at threshold with 1–2 min jog); optional short VO2max intervals (5–6 × 3–4 min) for faster runners; first marathon-pace segments
Specific	last 8–10 weeks before the taper	Marathon-pace runs of 8–20 km and marathon-pace long runs; threshold kept once a week; VO2max work minimal
Taper	last 2–3 weeks	Short marathon-pace and threshold touches; volume cut

• At most two quality sessions a week besides the long run, never on consecutive days. A runner on three or four days a week does one quality session and the long run.
• Tempo or threshold running more than once a week adds fatigue without adding much for most runners.
• Strides (6–10 × 20 seconds, relaxed and fast, full recovery) fit on one or two easy days every week of the block except race week.

Setting marathon pace

Goal pace comes from a recent race, ideally a half marathon four to eight weeks into the block. The standard conversion (about 2.09 times the half-marathon time) is too optimistic for many recreational runners: for half of them it predicted a marathon at least ten minutes faster than they ran, and for a quarter more than twenty. The error is smaller the more a runner trains — weekly volume improves the prediction more than any formula. Treat the converted time as the fastest realistic target and check it in marathon-pace long runs: if 12–16 km at goal pace late in a long run is not controlled, the goal is too fast.

The Taper

• Two to three weeks. The best-supported taper lasts about two weeks and cuts volume by 41–60%, progressively rather than in one step; in a large dataset of marathoners, a strict three-week taper was worth about 2–3% of finish time over a minimal one, and four weeks was no better than three.
• Keep intensity: short marathon-pace and threshold segments stay in.
• Keep frequency: about the same number of runs, each shorter.

Week	Volume (of peak)	Long run	Quality
Race −2	about 75%	90–120 min easy, or with 6–8 km at marathon pace	one marathon-pace or threshold session
Race −1	about 60%	60–75 min easy	one short marathon-pace session early in the week
Race week	about 40% before the race	—	3–5 km at marathon pace three or four days out; strides

Fuelling and Hydration

• During the race: about 30–60 g of carbohydrate per hour for two to two and a half hours of running, and up to 90 g per hour beyond that. Above about 60 g per hour the carbohydrate should come from glucose–fructose mixtures. Slower runners need it at least as much as faster ones, because they are out longer.
• Train the gut: practise the race intake in long runs for several weeks. Two weeks of repeated carbohydrate intake during training reduced gastrointestinal symptoms and improved performance.
• Carbohydrate loading: 10–12 g of carbohydrate per kilogram of body weight per day for the 36–48 hours before the race, with lower fibre.
• Race morning: 1–4 g/kg of carbohydrate one to four hours before the start.
• Fluids: avoid both large fluid losses and drinking well beyond thirst, which risks low blood sodium in slow runners.

Pacing the Race

An even or slightly negative split is the most reliable plan. The first 5 km should be no faster than goal pace, even if it feels easy — that ease is the point. Heart rate drifts upward at constant pace over the race; chasing a fixed heart rate in the second half produces slowing that is not needed.

Strength Training and the Hybrid Athlete

• Heavy strength work (loads of about 80% of 1RM or more) combined with plyometrics improves running economy by about 2–8% and time-trial performance by 2–4%, without adding body mass. Combined methods show the largest effect; plyometrics alone the smallest. Age and sex do not change the response.
• Two sessions a week in the base and build phases, one maintenance session in the last three or four weeks, none or a very light one in race week.
• Running straight before lifting blunts the benefit, and concurrent training mainly costs explosive strength when both are in the same session: separate them by at least three hours. Heavy lower-body work goes on a quality day after the run, or on an easy day — never the day before the long run or a key session.
• Lower-body volume stays modest: the running provides the leg volume. Single-leg work, calves and hamstrings carry the most value for runners.
• Lighter strength weeks coincide with lighter running weeks, so that both recover together.

Masters Runners (45 and over)

• Marathon times change little between about 20 and 55; endurance performance then declines more steeply after 60, driven mostly by VO2max, while running economy does not change with age. Much of the decline follows reduced training volume and intensity, so consistent training matters more, not less. Age-graded targets are fairer than absolute ones.
• After hard sessions masters runners recover physical performance about as fast as younger runners, but report more fatigue and soreness for longer. Two quality sessions a week at most — one can be the marathon-pace long run — with easy days between them, and a lighter week every third week.
• Recovery from muscle-damaging sessions is slower, and protein after training may need to be higher than the usual 20 g.
• Strength training stays in the plan, with fewer hard sets and slower progressions.
• Start from the athlete's real current volume and build gradually; the longer preparation (18–24 weeks) gives room to do so.

Common Mistakes

• Running easy runs and long runs too fast, so that the quality sessions are run tired.
• Marathon pace in every long run, or long runs well over three hours.
• Too much VO2max work for an event decided by threshold and durability.
• Cramming volume late, or a plan that finishes before the race.
• Never rehearsing race fuelling, then trying something new on race day.
• A goal pace converted from a shorter race and never checked in long runs.

Key Takeaways

1. Build the plan backwards from race day: taper on the race, specific phase before it, base before that.
2. Volume is the strongest training lever; build about 10% per week between loading weeks, avoid spikes, and use a lighter week every third or fourth week.
3. Long runs reaching 30–35 km (or about 2:30–3:00 for slower runners), the longest three to five weeks out.
4. Marathon pace belongs in the last 8–10 weeks, often inside long runs, alternating with easy long runs.
5. Keep most running easy; threshold work once a week; VO2max work sparing.
6. Taper two to three weeks, cutting volume 40–60% progressively and keeping intensity.
7. Fuel up to 60–90 g of carbohydrate per hour in the race, rehearsed in training.