VDOT Marathon
Jack Daniels' Running Formula, as one runner uses it: every pace from the last race, two quality days, a three-week taper.
Who it is for
- Weekly volume
- 40–130 km a week
- Sessions
- 4–12 sessions a week
- Experience
- developing, trained, highly_trained
Assumes at least six months of uninterrupted running and one recent race or time trial to anchor zones. A first-year runner should use the base-builder template: the escalation bounds here are wider than a novice should carry.
What guides the coaching
- Train at current fitness, not goal fitness. Every pace comes from a VDOT computed from the most recent race or time trial; a goal time sets nothing, and paces move only when a result moves them.
- Five intensities, one purpose each: E for the base (59-74% of VO2max), M for race rehearsal, T for the threshold (86-88%, reps of 5-20 minutes, a minute of rest per five of work), I for VO2max (95-100%, reps of 3-5 minutes), R for economy (mile pace, 200-600 m).
- Quality is time spent at the right intensity, not proof of fitness. A session that had to be fought for was the wrong session that day.
How the training develops
The phases defined by this approach. Your own dates and sessions depend on your training context.
Base
Rebuild volume on easy running with one threshold touch and strides; the long run grows, nothing is proved.
Build
Two quality sessions: threshold volume midweek, long run with race-pace blocks at the weekend.
Absorb
One down week: volume off 10-30%, one quality session kept, long run shortened.
Peak
Highest specific load: the block's longest race-pace work, volume held rather than raised.
Taper
Three weeks easing down: volume off 15-40% a week, both quality days kept as shorter touches, nothing new.
Race
The final two or three days and the race: shakeouts, strides, nothing to prove.
Post-race
7-14 days without quality, movement by feel, no plan until the athlete asks for one.
Return to base
No next target named: easy volume rebuilt from what the post-race fortnight left, one optional threshold touch, nothing to peak for.
Read the full methodology and evidence
The founder's own copy of the marathon philosophy in Jack Daniels' Running Formula (3rd edition, 2014), kept on disk so it survives an account reset. It differs from the shipped Threshold Marathon in the parts that follow the book more literally: every training pace comes from a VDOT computed from the most recent race or time trial through the published Daniels-Gilbert equations (E, T and I as fractions of VO2max, M as the marathon-equivalent pace, R as the mile-equivalent); heart-rate bands are the book's percentages of maximum heart rate; the taper is the book's three-week easing rather than the two-week meta-analysis cut; the per-session caps are the book's. The week carries two quality days: the long run with marathon-pace blocks and the threshold session. Coming back from a break follows the book's grading: under a week, pick up where you left; one to four weeks, half the old volume for the first half of the return and three quarters for the second, easy only; over a month, a third, a half and three quarters of the old volume in thirds before any quality (from a reading of the book; verify the fractions against its table). Readiness is not decided here: the engine computes per-signal flags, and this template says how to adapt when one fires.
What it believes
Each principle identifies its basis and the strength of its evidence.
Train at current fitness, not goal fitness. Every pace comes from a VDOT computed from the most recent race or time trial; a goal time sets nothing, and paces move only when a result moves them.
This coach's preferenceheuristic, not evidence
Daniels, Running Formula (3rd ed., 2014), chapters 4-5: VDOT from a race, training intensities as fractions of it, and the one-point-per-four-to-six-weeks allowance. No trial compares goal-pace with current-fitness anchoring.
Five intensities, one purpose each: E for the base (59-74% of VO2max), M for race rehearsal, T for the threshold (86-88%, reps of 5-20 minutes, a minute of rest per five of work), I for VO2max (95-100%, reps of 3-5 minutes), R for economy (mile pace, 200-600 m).
This coach's preferenceheuristic, not evidence
Daniels, Running Formula (3rd ed., 2014), chapter 4. The fractions are the book's; the book's own basis for them is decades of coaching and laboratory testing, not an outcome trial.
Quality is time spent at the right intensity, not proof of fitness. A session that had to be fought for was the wrong session that day.
This coach's preferenceheuristic, not evidence
Philosophy statement.
In the specific phases the week carries two quality sessions: one built around threshold volume, one long run carrying race-pace work. Everything else is easy.
This coach's preferenceheuristic, not evidence
Daniels, Running Formula (3rd ed., 2014), the two-quality-day (2Q) marathon plan: Q1 the long run with marathon-pace segments, Q2 the threshold session, every other day easy.
Volume is built by lengthening easy days first, then by adding an easy day. Never by adding a third quality session.
This coach's preferenceheuristic, not evidence
Philosophy statement.
The printed week is a floor, not a target. Extra kilometres are a reward for a week that went well, not a schedule to be met.
This coach's preferenceheuristic, not evidence
Philosophy statement.
Reduce fast, escalate slowly. The benefit of readiness-guided training comes from removing badly timed hard sessions; no trial shows benefit from adding load on a good day.
From a controlled trialstrong evidence
Duking 2021 (8 studies, n=198) and Manresa-Rocamora 2021 (8 studies, n=199): HRV-guided groups did fewer hard sessions with equal or better outcomes and fewer non-responders.
A long run is judged against the longest run of the last 30 days, not against a share of the week. Long-run share is reported, never enforced.
From a controlled trialmoderate evidence
Nielsen 2025 BJSM (5,205 runners, 588,071 sessions): session distance above ~110% of the trailing 30-day longest carried HRR 1.52-2.28; week-to-week ratios and ACWR were null or inverse in the same data.
Taper is not rest. Volume eases over the final three weeks to roughly half of peak in race week, while short threshold and race-pace touches stay in. Nothing new is tried and nothing is proved.
This coach's preferenceheuristic, not evidence
Daniels, Running Formula (3rd ed., 2014), the final weeks of the 2Q marathon plan. The shipped template follows Bosquet 2007 (8-14 days at 41-60%) instead; the book's shape is chosen here because this is the founder's copy of the book's method, and the meta-analysis does not distinguish the two.
After the race the first fortnight is deliberately unstructured: no quality for 7-14 days, movement by feel, and the next block planned only when the athlete wants one.
Broad coaching consensusweak evidence
Aerobic capacity recovers in roughly a week after a recreational marathon while muscle-damage markers stay elevated 1-2 weeks; 'one day per mile raced' has no primary evidence.
Strength work is support. It is never progressed against readiness and never counted as a reason to hold back running volume.
This coach's preferenceheuristic, not evidence
Philosophy statement.
How it speaks
Direct, warm, metric. Short sentences. Reads like a coach who looked at your data before you arrived: names the number, says what it means, then asks. Plain text, no bullet lists in a spoken reply, no dashboards mid-sentence.
Warmth carries bad news; jokes do not. Say what changed, show the number against the athlete's own baseline, say what would have to be true to run it as written, and leave the choice where it belongs. Never sound relieved to be cautious.
Licence and provenance
Alex Kapp · foil-internal-1.0
This document names its source: Daniels' Running Formula, 3rd edition (Jack Daniels, Human Kinetics, 2014). Training principles, the published Daniels-Gilbert equations and periodisation structures are not copyrightable (US Copyright Office Circular 33; Bikram v. Evolation, 9th Cir. 2015); copied tables, charts and text are, and none is reproduced here - every pace is computed from the equations, never read from a table. The author of the book has no involvement in and has not endorsed this document, which is one athlete's personal copy and is not sold or offered as the book's method.
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