{"success":true,"version":"v1","request":{"tool":"get_calculator_schema","calculator_id":"vdot-training-paces"},"result":{"entity_type":"calculator","id":"vdot-training-paces","calculator_id":"vdot-training-paces","canonical_url":"https://tttkmbb.com/fitness/vdot-training-paces","name":"VDOT Training Paces Calculator","title":"VDOT Calculator – Daniels' Running Formula Training Paces (Easy, Marathon, Threshold, Interval, Repetition) from a Race Result","category":"fitness","category_name":"Sports & Fitness","tool_name":"calculate_vdot_training_paces","featured_mcp_tool":false,"description":"Estimates VDOT (Jack Daniels' pseudo-VO2max) from one race distance and time with the Daniels & Gilbert oxygen-cost and duration equations, then derives Easy, Marathon, Threshold, Interval and Repetition training paces per km and per mile.","use_when":"You have a recent race or time-trial result and want Daniels-style training paces or a VDOT value to compare fitness over time.","do_not_use_when":"You only want predicted finish times for other distances (use race-time-predictor), or you have a measured VO2max from a lab test (VDOT is a performance index, not a physiological measurement).","inputs":[{"name":"distance","label":"Race distance","type":"number","required":true,"max":500,"exclusive_min":0,"description":"Distance of the race or time trial, in distance_unit (e.g. 5, 10, 21.0975, 42.195 km).","example":5},{"name":"distance_unit","label":"Distance unit","type":"enum","required":false,"default":"km","values":[{"value":"km","label":"Kilometres","aliases":["kilometers","kilometres","k"]},{"value":"mi","label":"Miles","aliases":["mile","miles"]}],"description":"Unit of the distance input.","example":"km"},{"name":"time","label":"Race time","type":"string","required":true,"description":"Finish time as h:mm:ss (3:30:00), mm:ss (25:00) or plain minutes.","example":"25:00"}],"outputs":[{"name":"vdot","label":"VDOT","type":"number","decimals":1,"description":"Daniels' VDOT = VO2 at race pace / fraction of VO2max sustainable for the race duration (ml/kg/min)."},{"name":"vo2_at_race_pace_ml_kg_min","label":"Oxygen cost of race pace","type":"number","unit":"ml/kg/min","decimals":1,"description":"−4.60 + 0.182258·v + 0.000104·v² with v in m/min."},{"name":"percent_vo2max_sustained","label":"% VO2max sustained","type":"number","unit":"%","decimals":1,"description":"Fraction of VO2max a runner can hold for the race duration (Daniels & Gilbert curve)."},{"name":"race_pace_per_km","label":"Race pace","type":"string","unit":"min:sec/km","decimals":4,"description":"Average pace of the input race."},{"name":"easy_pace_per_km","label":"Easy pace (59–74 %)","type":"string","unit":"min:sec/km","decimals":4,"description":"Easy / long-run pace range, slow to fast."},{"name":"marathon_pace_per_km","label":"Marathon pace (75–84 %)","type":"string","unit":"min:sec/km","decimals":4,"description":"Marathon-effort pace range."},{"name":"threshold_pace_per_km","label":"Threshold pace (83–88 %)","type":"string","unit":"min:sec/km","decimals":4,"description":"Tempo / cruise-interval pace range."},{"name":"interval_pace_per_km","label":"Interval pace (95–100 %)","type":"string","unit":"min:sec/km","decimals":4,"description":"VO2max interval pace range (3–5 minute repeats)."},{"name":"repetition_pace_per_km","label":"Repetition pace (105–110 %)","type":"string","unit":"min:sec/km","decimals":4,"description":"Fast repetition pace range (200–400 m repeats)."},{"name":"training_paces","label":"All training paces","type":"list","decimals":2,"description":"Per zone: name, percent_vo2max, pace_per_km, pace_per_mile (slow–fast) and speed_kmh at the midpoint."}],"input_schema":{"type":"object","properties":{"distance":{"description":"Distance of the race or time trial, in distance_unit (e.g. 5, 10, 21.0975, 42.195 km).","type":"number","maximum":500,"exclusiveMinimum":0,"examples":[5]},"distance_unit":{"description":"Unit of the distance input.","type":"string","enum":["km","mi"],"default":"km","examples":["km"]},"time":{"description":"Finish time as h:mm:ss (3:30:00), mm:ss (25:00) or plain minutes.","type":"string","examples":["25:00"]}},"additionalProperties":false,"required":["distance","time"]},"output_schema":{"type":"object","properties":{"vdot":{"description":"Daniels' VDOT = VO2 at race pace / fraction of VO2max sustainable for the race duration (ml/kg/min).","type":"number"},"vo2_at_race_pace_ml_kg_min":{"description":"−4.60 + 0.182258·v + 0.000104·v² with v in m/min. Unit: ml/kg/min.","type":"number","x-unit":"ml/kg/min"},"percent_vo2max_sustained":{"description":"Fraction of VO2max a runner can hold for the race duration (Daniels & Gilbert curve). Unit: %.","type":"number","x-unit":"%"},"race_pace_per_km":{"description":"Average pace of the input race. Unit: min:sec/km.","type":"string","x-unit":"min:sec/km"},"easy_pace_per_km":{"description":"Easy / long-run pace range, slow to fast. Unit: min:sec/km.","type":"string","x-unit":"min:sec/km"},"marathon_pace_per_km":{"description":"Marathon-effort pace range. Unit: min:sec/km.","type":"string","x-unit":"min:sec/km"},"threshold_pace_per_km":{"description":"Tempo / cruise-interval pace range. Unit: min:sec/km.","type":"string","x-unit":"min:sec/km"},"interval_pace_per_km":{"description":"VO2max interval pace range (3–5 minute repeats). Unit: min:sec/km.","type":"string","x-unit":"min:sec/km"},"repetition_pace_per_km":{"description":"Fast repetition pace range (200–400 m repeats). Unit: min:sec/km.","type":"string","x-unit":"min:sec/km"},"training_paces":{"description":"Per zone: name, percent_vo2max, pace_per_km, pace_per_mile (slow–fast) and speed_kmh at the midpoint.","type":"array"}}},"formula":"v = distance_m / t_min; VO2 = −4.60 + 0.182258·v + 0.000104·v²; %VO2max = 0.8 + 0.1894393·e^(−0.012778·t) + 0.2989558·e^(−0.1932605·t); VDOT = VO2 / %VO2max; training velocity for a fraction p: solve 0.000104·v² + 0.182258·v − (4.60 + p·VDOT) = 0, pace = 60000 / v seconds per km; zones Easy 59–74 %, Marathon 75–84 %, Threshold 83–88 %, Interval 95–100 %, Repetition 105–110 % of VDOT","method":"This is Jack Daniels' VDOT method (Daniels & Gilbert 1979, Daniels' Running Formula). The zone percentages are the ranges Daniels gives for each intensity; his published tables apply small race-duration-specific adjustments, so paces here can differ from the book tables by a few seconds per km and are approximate.","sources":[{"name":"Daniels J, Gilbert J (1979) Oxygen Power: Performance Tables for Distance Runners","url":"https://www.worldcat.org/search?q=Oxygen+Power+Performance+Tables+for+Distance+Runners","type":"textbook","retrieved_at":"2026-09-24"},{"name":"Daniels J (2021) Daniels' Running Formula, 4th ed., Human Kinetics","url":"https://us.humankinetics.com/products/daniels-running-formula-4th-edition","type":"textbook","retrieved_at":"2026-09-24"}],"freshness":{"type":"static","max_age_seconds":null,"note":"Deterministic formula with fixed constants; results never go stale. Inputs supplied by the caller determine the output."},"examples":[{"name":"5 km in 25:00","inputs":{"distance":5,"distance_unit":"km","time":"25:00"},"expected":{"vdot":38.3,"vo2_at_race_pace_ml_kg_min":36,"percent_vo2max_sustained":94,"race_pace_per_km":"5:00","easy_pace_per_km":"7:14–6:03","marathon_pace_per_km":"5:59–5:28","threshold_pace_per_km":"5:31–5:16","interval_pace_per_km":"4:57–4:45","repetition_pace_per_km":"4:34–4:24"},"url":"https://tttkmbb.com/api/v1/calculate/vdot-training-paces?distance=5&distance_unit=km&time=25%3A00"},{"name":"Marathon in 3:30:00","inputs":{"distance":42.195,"distance_unit":"km","time":"3:30:00"},"expected":{"vdot":44.6,"percent_vo2max_sustained":81.3,"race_pace_per_km":"4:59","threshold_pace_per_km":"4:54–4:40","marathon_pace_per_km":"5:19–4:51"},"url":"https://tttkmbb.com/api/v1/calculate/vdot-training-paces?distance=42.195&distance_unit=km&time=3%3A30%3A00"}],"faq":[{"q":"Is VDOT the same as VO2max?","a":"No. VDOT is the VO2max a runner would have if their running economy matched Daniels' reference curve; it is a performance index in VO2max units. Lab VO2max can be several points higher or lower."},{"q":"Which race gives the best VDOT?","a":"A recent all-out race of 5 km to half marathon on a flat course. Short races (mile) overestimate endurance paces and a marathon slowed by fuelling or heat underestimates VDOT."},{"q":"Why do these paces differ slightly from the book tables?","a":"The tables round and adjust each zone for typical repetition lengths; this calculator applies the zone percentages directly to the VDOT equations, so expect differences of a few seconds per km."}],"tags":["vdot calculator","daniels running formula","training paces","threshold pace","easy pace","interval pace"],"related":[{"calculator_id":"race-time-predictor","reason":"Riegel-based finish-time predictions for other distances."},{"calculator_id":"running-pace","reason":"Pace and splits for a distance and time."},{"calculator_id":"vo2-max","reason":"Field-test estimates of physiological VO2max."}],"links":{"html":"https://tttkmbb.com/fitness/vdot-training-paces","markdown":"https://tttkmbb.com/fitness/vdot-training-paces.md","json":"https://tttkmbb.com/fitness/vdot-training-paces.json","api":"https://tttkmbb.com/api/v1/calculate/vdot-training-paces","schema":"https://tttkmbb.com/api/v1/calculators/vdot-training-paces","openapi":"https://tttkmbb.com/openapi.json","mcp":"https://tttkmbb.com/mcp"},"version":"v1","updated_at":"2026-09-24"},"timestamp":"2026-09-24T01:45:52Z","next_actions":[{"tool":"run_calculator","calculator_id":"vdot-training-paces","reason":"Run VDOT Training Paces Calculator with the inputs above."}],"links":{"markdown":"https://tttkmbb.com/fitness/vdot-training-paces.md"}}