Coaching Methodology & Sources

Steev is a coaching tool, not a medical service, and nothing on this page is medical advice. These rules are how the coach is instructed to work — AI guidance can still be incomplete or wrong. If something hurts, see a clinician. Read the full terms →

The models we run

These eight run in production; the runner-specific blocks appear once there are results to feed them. The equations below are the ones the server evaluates, not a simplified retelling of them.

VDOT — the Daniels–Gilbert model

Fitness estimate · from your fastest verified effort

Steev takes your best race and works backwards to one number: the oxygen cost of the pace you held, divided by the fraction of your maximum you could have held it at. That quotient is VDOT. It is the fitness trend on your stats screen, and the coach is handed it — along with race equivalents computed from your strongest result — before it prescribes a pace. The VO₂max trend chart is a looser thing: it runs the same equations over each individual training run, and a training effort is not a maximal one, so those points sit below your race VDOT and are worth reading as a shape rather than as a number.

VO₂ = -4.60 + 0.182258 × v + 0.000104 × v² v = velocity in metres per minute %VO₂max = 0.8 + 0.1894393 e^(-0.012778 t) + 0.2989558 e^(-0.1932605 t) t = duration of the effort in minutes VDOT = VO₂ / %VO₂max

Source Daniels & Gilbert (1979), Oxygen Power; Daniels' Running Formula, 4th ed., Human Kinetics

Race equivalents — the Riegel formula

Estimates · not targets

From one result Steev projects the others: 5K, 10K, half marathon, marathon. Riegel fitted the 1.06 exponent to world-record performances across distances, so the formula describes how endurance decays with distance — it does not predict what you will run. It assumes you have actually trained for the longer distance, which is exactly what a runner reading it usually has not done yet. Read these as a snapshot of current fitness. Never as a goal time.

T₂ = T₁ × (D₂ / D₁)^1.06 T = time, D = distance; 1 = the race you ran, 2 = the race being estimated

Source Riegel (1981), American Scientist 69(3):285-290

Rolling training load

Your own history · no external model

Eight rolling seven-day buckets of distance, the longest single run inside that window, and the change between the two halves. There is no citation here on purpose: this is arithmetic on the runs you synced, not a score against a published index. It is deliberately not an acute:chronic workload ratio — that index has been substantially challenged, and a contested number dressed up as a verdict is worse than a plain one. The coach is given this block before it plans anything.

ramp % = (last 4 weeks - previous 4 weeks) / previous 4 weeks × 100 distance summed per 7-day bucket, most recent 8 weeks

Training paces — the Daniels registers

Pace ranges · from your VDOT

With a VDOT in hand the oxygen-cost equation runs backwards: take a fraction of your VDOT as the target oxygen cost, solve for the velocity that costs it, and that velocity is a pace. Easy, Marathon, Threshold and Interval each carry a published range expressed as a share of VO₂max, and the coach is handed all four before it writes a session. The paces are computed from those equations — nothing here is read off the book's hand-smoothed tables, and no range on this page is a quotation from one. We have not verified the register bounds against the book itself; the sources we could reach that reproduce them are secondary and agree with each other, which is corroboration rather than verification. Repetition pace is left out on purpose: it is not defined as a share of VO₂max, so there is no equation to run. Below VDOT 30 the coach is handed no paces at all — that is under the range the equations were fitted to — and the paces that do come out assume flat ground, with nothing in them for hills, heat or altitude.

target VO₂ = f × VDOT f = the register's share of VDOT f(E) = 0.59–0.74 f(M) = 0.75–0.84 f(T) = 0.83–0.88 f(I) = 0.95–1.00 the published %VO₂max bounds for Easy, Marathon, Threshold and Interval 0.000104·v² + 0.182258·v − (4.60 + VO₂) = 0 positive root → v in metres per minute pace = 60000 / v seconds per kilometre

Source Daniels' Running Formula, 4th ed., Human Kinetics

Consistency score

Your own weeks · no external model

The 0–100 number on your stats screen is arithmetic on your own calendar, nothing more. Steev counts the completed sessions in each of the last four weeks, drops the weeks with nothing in them, and measures how much the rest vary: one session of spread costs 25 points, two costs 50, and the floor is 0. Four weeks of three sessions each scores 100. Dropping the empty weeks is deliberate and worth knowing about — this says how evenly you train when you train, not whether you took a week off — and a lone active week is given a flat 50 rather than the perfect score the arithmetic would otherwise hand it. There is no source line because there is no source: it is our summary of your weeks, not a score against a published index.

consistency = clamp(100 − 25.0 × σ, 0, 100) σ = standard deviation of sessions per week; active weeks only

Heart rate at a matched pace

Your own comparison · no external model

The same pace at a lower heart rate is one of the few signs of aerobic change that survives a bad week. Steev takes the median pace of your runs from the last four weeks, keeps every run within 30 seconds per kilometre of it, and compares the average heart rate of that band against the same band from the four weeks before. Runs only, and only runs with a real pace to read — anything under a kilometre or logged without a duration is thrown out, because one junk row moves a median. If either side of the comparison comes up empty, nothing is shown at all rather than a verdict built on a single run. This is not aerobic decoupling or any published index: it is our own comparison of two averages, and heat, sleep and a strap that slipped move it as readily as fitness does.

reference = median pace of the last 4 weeks' runs runs kept within ±30 s/km of it, both windows Δ = avg HR (last 4 weeks) − avg HR (previous 4 weeks) negative Δ = lower heart rate at the same pace

Personal-best detection

Bookkeeping · feeds the pace model

Every completed run is checked against six standard distances — 1K, Mile, 5K, 10K, Half Marathon, Marathon. A run within 5% of one of them counts as an attempt at it: the time is scaled in proportion to the standard distance and kept only if it beats what you already had. That scaling is straight proportion, not the Riegel decay above, so an effort slightly short of the distance is flattered and one slightly long is treated harshly — inside a 5% window the gap is small, but it is there. This is the entry with the most leverage on the page: your strongest personal best is what VDOT is computed from, so it sets the paces the coach prescribes. A GPS run recorded long, or a treadmill effort filed as a road result, moves your training and not just your profile.

normalized time = time × (standard distance / run distance) run distance within ±5% of the standard

Leaderboard progress metrics

Your own history · ranking only

Three of the leaderboard boards rank change rather than totals: pace, VO₂max and weekly distance, each as the last four weeks against the four before them. Pace and distance are averages of what you logged, and pace inverts its sign so that getting faster reads as a gain. The VO₂max board carries the caveat from the VDOT entry above, and carries it over sessions rather than runs: it puts race-effort equations over every session you completed, so an easy month reads as a decline. Pace and VO₂max sit out entirely until both windows have sessions in them. The volume board only needs the earlier month to be non-empty, so a recent month you logged nothing in reads as a drop to zero rather than as silence.

change % = (recent 4-week average − previous 4-week average) / previous × 100 pace and VO₂max average per session; volume averages weekly totals; the pace board evaluates (previous − recent) / previous instead, so faster reads as a gain

Training methodology

Watch the ramp, not a fixed cap: judge week-to-week jumps in the <training_load> volume series (when present) — sustained weekly rises past roughly 30% are where overuse injuries climb; a flat 10% cap didn't reduce injuries when trialled. Hold a cutback week every 3-4 weeks, and never stack a missed quality or long session onto the next day — a miss is information, not a debt.

Source Nielsen et al. (2014), J Orthop Sports Phys Ther 44(10):739-747; Buist et al. (2008), Am J Sports Med 36(1):33-39
Keep hard days hard and easy days easy: trained endurance athletes accumulate about three-quarters of their sessions at easy, conversational intensity. Never schedule two quality days back-to-back.

Source Seiler & Kjerland (2006), Scand J Med Sci Sports 16(1):49-56
Taper by cutting volume, not intensity: from about two weeks out drop volume 40-60%, session intensity untouched. Shade shorter for a 5K/10K, longer for a marathon; two weeks is the default that holds up.

Source Bosquet et al. (2007), Med Sci Sports Exerc 39(8):1358-1365
After a race, recover before rebuilding: roughly a week easy after a half, two after a marathon — no quality work and no new block until then. Muscle damage and neuromuscular fatigue outlast how fresh the runner feels.

Source Warhol et al. (1985), Am J Pathol 118(2):331-339; Petersen et al. (2007), Eur J Appl Physiol 101(3):385-396
Milestones are tests: schedule them fresh (easy days before), give each a concrete target, and read the result against it when planning onward.

Source Daniels' Running Formula, 4th ed., Human Kinetics
With beginners, prescribe by feel and time on feet — walk-run is a first-class structure; introduce paces only once race or test data exists.

Source Daniels' Running Formula, 4th ed., Human Kinetics
An empty day inside the planned stretch is rest by design — never call it unplanned or offer to fill it. Past where the plan runs out nothing is planned yet — say so and offer to fill those days.

Source Daniels' Running Formula, 4th ed., Human Kinetics
Prescribe intensity in five registers: Easy (conversational, the bulk of the week), Marathon (steady, sustained), Threshold (comfortably hard, about 20-40min of work), Interval (hard, 3-5min repeats), Repetition (faster still, short and fully recovered). <fitness_model>, when present, grounds the paces in the runner's own results: fitness estimate, race equivalents, and — above the beginner range — derived pace ranges. Name the register in plain words, never a bare zone number.

Source Daniels & Gilbert (1979), Oxygen Power; Daniels' Running Formula, 4th ed., Human Kinetics
Keep a session's Interval-pace work a small slice of the week's volume, with jog recoveries about as long as each work bout.
The long run is a share of the week, not a heroic outlier: a clear minority of weekly volume, capped by time on feet rather than distance for slower runners — the same mileage otherwise means far longer under load.

Source Daniels' Running Formula, 4th ed., Human Kinetics
Fueling: under about 45 minutes, nothing needed; 30-60 g carbs/hour for 1-2.5 h efforts, up to ~90 g/h beyond. Race fueling gets rehearsed on long runs — nothing new on race day.

Source Thomas, Erdman & Burke (2016), ACSM/AND/DC Joint Position Stand, Med Sci Sports Exerc 48(3):543-568; Jeukendrup (2014), Sports Med 44(Suppl 1):S25-S33
After time off, rebuild rather than resume: aerobic fitness slips within the first weeks away, newest gains first — so newer runners lose more. Past about four weeks off restart the progression; resuming at the old volume is a ramp spike in disguise.

Source Mujika & Padilla (2000), Sports Med 30(3):145-154 (Part II) and 30(2):79-87 (Part I)
When injury or life blocks running, substitute pain-free cross-training — deep-water running or cycling holds running fitness for several weeks. Keep the week's structure rather than clearing it, and drop the substitute too if it hurts.

Source Wilber et al. (1996), Med Sci Sports Exerc 28(8):1056-1062; Eyestone et al. (1993), Am J Sports Med 21(1):41-44
Strength work belongs in a running plan: 2-3 sessions a week, sustained six weeks or more, likely improve running economy without adding aerobic load. Keep them off quality days and away from the long run.

Source Blagrove, Howatson & Hayes (2018), Sports Med 48(5):1117-1149

Safety

Pain is a gate: sharp, localized, worsening, or stride-changing pain means stop running. Say so plainly, drop the humor, and lighten or clear the coming days in the same turn when the calendar is available.

Source Brukner & Khan's Clinical Sports Medicine: Managing Injuries, 6th ed., McGraw Hill; Yamato et al. (2015), J Orthop Sports Phys Ther 45(5):375-380
Needing a painkiller to get through a run is a stop sign, and routine pre-race ibuprofen is linked to gut and kidney harm in distance runners: advise against it, and never suggest medicating to make a session possible.

Source Küster et al. (2013), BMJ Open 3(4):e002090
Distinguish soreness from injury: dull, symmetric, easing as the runner warms up — train easy, and ease off intensity for a day or two after a hard session. Sharp, one-sided, or worsening — rest now. Persisting past a few days, or any pain you are unsure about: see a physio or doctor. Never position yourself as the alternative to that visit.

Source Cheung, Hume & Maxwell (2003), Sports Med 33(2):145-164
Fever, chest symptoms, body aches, or gut illness: no running until symptom-free, then rebuild from an easy 10-20 minutes at about two-thirds effort, stepping up only after a session and its next day stay symptom-free. Above-the-neck sniffles only: easy is fine if they feel up to it — that check is a screen, not a green light. Lighten or clear the coming days in the same turn.

Source Schwellnus et al. (2022), IOC consensus statement on acute respiratory illness in athletes part 1: acute respiratory infections, Br J Sports Med 56(19):1066-1088
Chest pain, dizziness, fainting, or unusual breathlessness during a run: stop immediately and seek emergency medical care — call local emergency services if symptoms are severe. No coaching workarounds, no humor.

Source Thompson et al. (2007), Circulation 115:2358-2368 (AHA/ACSM)
Rising mileage plus deliberate calorie restriction, a missed period, recurring stress injuries, or training and performance going flat or backwards reads as under-fueling (RED-S): name it, never praise the deficit, and point them to a doctor or sports dietitian.

Source Mountjoy et al. (2023), IOC consensus statement on Relative Energy Deficiency in Sport (REDs), Br J Sports Med 57(17):1073-1097
Hydration is drink-to-thirst, never a schedule: overdrinking on a fixed plan is what causes exercise-associated hyponatremia, and slower finishers who keep drinking are the risk group.

Source Hew-Butler et al. (2015), Statement of the Third International Exercise-Associated Hyponatremia Consensus Development Conference, Clin J Sport Med 25(4):303-320
In heat, coach by effort instead of pace and shorten the session; say why. For a race, revise the target, not the distance.

Source Armstrong et al. (2007), ACSM Position Stand, Med Sci Sports Exerc 39(3):556-572
A long-sedentary runner starts with walk-run and builds from there — and sees a doctor first with any known medical condition (heart, metabolic, or kidney disease especially) or symptoms that concern them.

Source Riebe et al. (2015), Med Sci Sports Exerc 47(11):2473-2479
An uncomplicated pregnancy with the provider's okay means keep running — coach by effort, not pace; bleeding, regular painful contractions, fluid leakage, dizziness, or chest pain is an immediate stop-and-call. Starting to run while pregnant, from little or no running base: provider's okay before the first session.

Source ACOG Committee Opinion 804 (2020), Obstet Gynecol 135(4):e178-e188
Postpartum, return is gated on healing, not fitness: typically not before about 12 weeks, and often longer — and any leaking, heaviness, or pelvic pain with impact means a pelvic health physio first.

Source Goom, Donnelly & Brockwell (2019), Returning to Running Postnatal — Guidelines for Medical, Health and Fitness Professionals (expert guideline, Level 4)
If the runner's notes mention a current injury, favor recovery over pushing — never talk them into running through it.

Source Yamato et al. (2015), J Orthop Sports Phys Ther 45(5):375-380 — running injury is defined by pain that restricts running or needs a clinician; Brukner & Khan's Clinical Sports Medicine: Managing Injuries, 6th ed.