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Prepare your race

Pick a race from the agenda, set the date, and get a phase plan computed backwards from race day. Then drop your Strava export to see your own numbers: weekly volume, longest sessions and pace trend. Everything runs in your browser.

A planning aid built on a common endurance periodisation structure, not coaching or medical advice. The analysis is classic statistics (weekly aggregates and a least-squares trend line), no black box.

A runner on a trail in the morning mist
John Robert McPherson · CC BY-SA 4.0

1 · Phase plan, computed back from race day

Set a race date to see the plan.

2 · Your training paces, from one recent race

Units

Enter a recent all-out race result. The tool computes your VDOT with the Daniels-Gilbert equations (1979) and derives the classic training zones, plus Riegel time predictions for other distances.

3 · Your numbers, from your Strava export

Strava → Settings → My account → Download or delete your account → request your archive, then drop the activities.csv from the ZIP here.

🔒 The file is parsed locally and never leaves your browser. Nothing is uploaded, nothing is stored.

How the analysis works
  • Weekly volume: activities grouped by ISO week (Monday), distances summed.
  • Longest session: the single longest activity of each week, a classic build-up marker.
  • Pace trend: least-squares linear regression on run pace over time. Descriptive, not predictive.
Fresh fruit and vegetables for balanced meal planning
Shixart1985 · CC BY 2.0

4 · Energy and fat loss

A body-composition companion, entirely local. Enter your figures to estimate your daily energy need, a safe rate of fat loss and a protein target, then log your weigh-ins to see the real trend under the daily noise.

Neither medical nor nutritional advice. These are standard estimates with about 30% unexplained variability (Mifflin 1990, R2 = 0.71); a starting point, not a prescription, and see a professional for anything that matters.

Units

Your weight trend

Log weigh-ins (same conditions each time). Daily weight is noisy; the trend line is a 10-day exponential moving average, the classic from The Hacker's Diet. Stored in your browser only.

Add at least 3 weigh-ins spanning a week to see a trend.

How the analysis works
  • Resting metabolism: Mifflin-St Jeor equation (1990).
  • Daily need: resting metabolism x an activity factor. The common gym multipliers (1.2 to 1.9) are conventional and have no single primary source; the peer-reviewed FAO ranges are 1.4 to 2.4.
  • Deficit: the static 7700 kcal/kg rule, shown with its published limit (Hall 2008).
  • Weight trend: exponential moving average; the projected date is a linear extrapolation of that trend, not a promise.

Heart-rate zones

Same idea as the coloured effort bars on your watch. Enter your age (or your measured max) and see your five training zones in beats per minute; drop in a session's average and peak to see which zones you trained.

Estimated max HR187 bpm
Z1
Recovery
94112
Z2
Endurance
112131
Z3
Tempo
131150
Z4
Threshold
150168
Z5
Anaerobic
168187

A session's heart rate

Max HR is estimated with Tanaka (208 − 0.7 × age), more accurate than the old 220 − age. A measured max from a maximal test is best. Not medical advice. Source

Muscle map

The body chart from your workout screen. Tick the exercises you did and the map lights up the muscles they work: bright for prime movers, faint for the muscles that assist and stabilise.

Exercises in your session

FRONTBACK
Prime moverAssists / stabilises

Pick one or more exercises to light up the map.

Sleep: when to go to bed

Recovery starts the night before. Sleep runs in cycles of about 90 minutes; this counts them backwards from your alarm (or forwards from bedtime), adding the time it takes to fall asleep. In a Stanford study, basketball players who extended their sleep sprinted faster and shot more accurately (Mah 2011).

  • 21:156 cycles · 9 h of sleep7-9 h
  • 22:455 cycles · 7 h 30 of sleep7-9 h
  • 00:154 cycles · 6 h of sleep
  • 01:453 cycles · 4 h 30 of sleep

A heuristic, not a prescription: real cycles vary between people and across the night (roughly 70-120 min, the first is shorter), and the evidence that waking from deep sleep feels worse is mixed (Hilditch 2019). Adults are recommended 7-9 hours (Hirshkowitz 2015). Not medical advice. Source

FAQ

Does my Strava data get uploaded anywhere?
No. The CSV is parsed in your browser with JavaScript; there is no upload, no server, no account, and closing the tab clears everything.
Which races is the planner for?
Any endurance start line: 10k, half marathon, marathon, trail, triathlon or Ironman. The phase structure (base, build, peak, taper) is the same, only the date changes.
Is this a training plan?
No. It is a calendar aid built on a common periodisation structure, plus descriptive statistics of your own past training. For a plan tailored to you, work with a coach.
How does the VDOT pace calculator work?
Enter one recent race result and the tool derives your VDOT from the Daniels-Gilbert model (velocity at VO2max and the fraction of VO2max you can hold for that duration), then gives easy, marathon, threshold, interval and repetition paces. It is a running pace calculator, not coaching.
How do you estimate calories to lose fat (TDEE)?
The health tool computes your BMR with the Mifflin-St Jeor equation, multiplies by an activity factor for TDEE, and converts a weekly weight-loss target into a daily deficit using the classic 7700 kcal/kg rule. It shows the Hall 2008 caveat that this static rule overestimates long-term loss, and every formula links to its primary source.
What time should I go to bed to wake up at 6:30?
Count back five or six sleep cycles of about 90 minutes, plus the time you take to fall asleep (10-20 minutes for most adults). For a 6:30 alarm that means lights out around 22:45 (5 cycles, 7 h 30) or 21:15 (6 cycles, 9 h). The sleep calculator on this page does the counting for any time, both directions, and shows which options land in the recommended 7-9 hours.
Does it work in miles and pounds?
Yes. A units switch on the page flips every tool to imperial: training paces in minutes per mile, race distances in miles, body weight in pounds and height in feet and inches. The conversion uses the exact international factors (1 mi = 1,609.344 m; 1 lb = 0.45359237 kg) and your choice is remembered locally.
Can I use the analyzer without a Strava export?
Yes. Open “No export? Enter sessions by hand” and log a few sessions (date, sport, distance, minutes). You get the same weekly-volume, pace-trend and training-load charts, and the entries stay in your browser.

Sources

Every formula on this page comes from the references below, coefficients verified against the primary source and recomputed independently.

  • Riegel (prediction) · Riegel P.S., Athletic Records and Human Endurance, American Scientist 69(3):285-290, 1981 (formule T2 = T1 x (D2/D1)^1.06 : Runner's World, 1977)
  • Riegel, limites · Vickers A.J., Vertosick E.A., An empirical study of race times in recreational endurance runners, BMC Sports Sci Med Rehabil 8:26, 2016
  • VDOT · Daniels J., Gilbert J., Oxygen Power: Performance Tables for Distance Runners, 1979 ; zones d'allure : Daniels' Running Formula
  • ACWR · Gabbett T.J., The training-injury prevention paradox, Br J Sports Med 50(5):273-280, 2016
  • ACWR, limites · Impellizzeri F.M. et al., Acute:Chronic Workload Ratio: Conceptual Issues and Fundamental Pitfalls, Int J Sports Physiol Perform 15(6):907-913, 2020
  • Monotonie · Foster C., Monitoring training in athletes with reference to overtraining syndrome, Med Sci Sports Exerc 30(7):1164-1168, 1998
  • Affûtage · Bosquet L., Montpetit J., Arvisais D., Mujika I., Effects of tapering on performance: a meta-analysis, Med Sci Sports Exerc 39(8):1358-1365, 2007
  • Métabolisme de base · Mifflin M.D. et al., A new predictive equation for resting energy expenditure in healthy individuals, Am J Clin Nutr 51(2):241-247, 1990
  • Niveaux d'activité (PAL) · Human energy requirements, Report of a Joint FAO/WHO/UNU Expert Consultation, 2001/2004
  • Règle du déficit, limites · Hall K.D., What is the required energy deficit per unit weight loss?, Int J Obes 32(3):573-576, 2008 (la règle statique 7700 kcal/kg de Wishnofsky 1958 surestime la perte à long terme)
  • Taux de perte · Helms E.R., Aragon A.A., Fitschen P.J., Evidence-based recommendations for natural bodybuilding contest preparation, J Int Soc Sports Nutr 11:20, 2014
  • Protéines · Morton R.W. et al., A systematic review, meta-analysis and meta-regression of protein supplementation..., Br J Sports Med 52(6):376-384, 2018
  • Cycles de sommeil · Institute of Medicine, Sleep Disorders and Sleep Deprivation, ch. Sleep Physiology, 2006 (cycle ~90 min ; 1er cycle 70-100 min, suivants 90-120 min)
  • Durée de sommeil · Hirshkowitz M. et al., National Sleep Foundation's sleep time duration recommendations, Sleep Health 1(1):40-43, 2015 (adultes : 7-9 h)
  • Inertie du sommeil · Hilditch C.J., McHill A.W., Sleep inertia: current insights, Nat Sci Sleep 11:155-165, 2019 (dissipation ~30-60 min ; preuves mitigées sur le stade au réveil)
  • Sommeil & performance · Mah C.D. et al., The effects of sleep extension on the athletic performance of collegiate basketball players, SLEEP 34(7):943-950, 2011

🏃 Races in the agenda