Marathon Training Blocks With Readiness Checks

A marathon build works best as three blocks with different jobs: base, specific, and taper. Each block has a fixed purpose and a fixed long-run pattern, and readiness decides how much of each session you run. The block structure keeps you honest about progression. The readiness layer keeps the peak weeks survivable.

Why blocks instead of one 18-week plan

A single continuous plan asks every week to do everything: build volume, sharpen speed, rehearse race pace, and stay fresh. Blocks separate those jobs so each gets a clear window, which makes it obvious what to cut when a week goes badly.

Blocks also make progress measurable. In the base block you watch weekly volume and long-run duration. In the specific block you watch how much marathon-pace running you can hold late in a long run. In the taper you watch nothing except whether you are staying rested. Three different questions, three different kinds of evidence.

Block 1: base, weeks 1 to 8

Purpose: raise weekly volume, extend the long run, and build a threshold that makes marathon pace feel comfortably below it.

• Weekly structure: 5 to 6 runs, two quality sessions, one long run
• Quality 1: threshold. 4 x 8 min at threshold pace with 2 min jog, progressing to 2 x 15 min or 25 min continuous
• Quality 2: aerobic support. A 50 to 70 min progression run finishing at marathon pace, or a hill circuit of 8 to 10 x 60 s uphill
• Long run: 90 min rising to 130 min, all easy for the first four weeks
• Everything else easy, with 6 x 20 s hill sprints twice a week

Volume progression is the point of this block and where builds are most often ruined. Nielsen and colleagues (2014) found that novice runners who raised weekly distance by more than 30 percent over two weeks had a higher rate of distance-related injuries than those who progressed under 10 percent, and Gabbett (2016) argues that high chronic loads reached gradually are protective. Raise volume in small steps, hold each step for a week, and reduce every fourth week by 20 to 30 percent. The half marathon guide covers the progression pattern in detail, and it applies unchanged here.

Intensity distribution stays conservative: in a six-run week, two quality sessions and four easy runs. The easy runs guide covers why the four easy runs have to stay easy.

Block 2: specific, weeks 9 to 15

Purpose: make marathon pace durable when you are already tired, and rehearse fueling.

• Weekly structure: 5 to 6 runs, one threshold session, one long run containing race pace
• Quality 1: threshold maintenance. 3 x 10 min at threshold with 2 min jog, once a week, kept short
• Long run: 130 to 165 min with progressively more marathon-pace work in the second half
• Midweek medium-long run: 75 to 95 min easy
• Tune-up race: one half marathon or 10 mile race, 4 to 6 weeks out

The long-run progression is the block's engine.

Fuel every one of these as you intend to race, with the same products and the same timing. Gut tolerance is trainable, and race-day stomach trouble is usually a training omission rather than bad luck. The marathon fueling guide covers how many grams per hour and how to practice.

Block 3: taper, final 14 to 18 days

Purpose: arrive rested without losing sharpness.

• Cut weekly volume by about 30 percent in the first taper week and 50 percent in race week
• Keep two short sessions with race-pace content, for example 5 x 1 km at marathon pace eight days out and 4 x 800 m at marathon pace four days out
• Last longer run 10 to 12 days out, 90 to 100 min with 20 min at marathon pace
• Final three days: 30 min easy, 25 min easy with 4 x 200 m, then rest or a 20 min shakeout

The taper is fixed on purpose, and it is the one block where readiness data should be ignored. Volume drops, so HRV rises and resting heart rate falls, and those changes reflect reduced load rather than an invitation to add work. Runners who adapt their taper upward on the strength of good readiness scores train through the one period designed to make them fresh.

The readiness layer, block by block

Readiness resizes sessions. It does not change what block you are in.

Three constraints keep this coherent.

1. Never reduce the long run in two consecutive weeks unless you are ill or injured. Long-run frequency drives the block.
2. Never move a long run next to a quality session as a result of rescheduling.
3. If three straight weeks are yellow or red, the plan is too ambitious. Cut peak weekly volume by 15 percent and continue rather than failing the same week again.

Foster (1998) supplies the logic for the third rule. In 25 experienced athletes, illness clustered when individuals exceeded personal thresholds of accumulated training strain. A plan that generates repeated yellow and red days is producing strain you are not converting into fitness.

Vitadel Run applies this layer automatically. The block structure comes from your plan, and each day's session is resized against a readiness color built from sleep, HRV, resting heart rate, training load, and a morning check-in. Readiness scores explained covers what feeds that color.

Weekly volume across the build

Peak weekly volume depends on history, not ambition. A runner whose highest previous week is 35 miles (55 km) should peak near 45 miles (70 to 75 km), not 60.

Signals to change the plan rather than the session

• Easy pace at a fixed heart rate has slowed across three weeks with no volume increase.
• The marathon-pace block inside long runs is drifting slower week over week at the same effort.
• The 7-day average resting heart rate is more than 4 beats above your 4-week average for a week.
• The 7-day average sleep has dropped by an hour or more during peak weeks. Fullagar and colleagues (2015) found reduced sleep impairs sport-specific performance and can mimic overtraining.
• Any local pain that changes your stride, which outranks every other signal here.

The first four call for a reduced week and a lower peak. The last calls for a diagnosis before another long run.

Setting a goal pace you can defend

Derive goal marathon pace from the tune-up race, not from ambition or a 5K time. A half marathon result four to six weeks out gives a defensible starting point for a runner with adequate long-run volume, and the VDOT guide explains why the marathon column of the equivalence table assumes that volume. Runners with lower weekly volume should expect a larger gap between the predicted time and what they can hold.

Then test it in training. If 50 minutes at goal pace at the end of a 155-minute long run is controlled and repeatable, the pace is real. If that block is a survival effort, the pace is aspirational, and race day will make that clear at mile 19. The race-day pacing guide covers the segment plan from there.