Race Week Math: Pace, Heart Rate, Steps, and Workout Calories

Race week is pace, pulse, distance, and load — four measurements, four tools, one calendar. Mixing them is how a 4-hour marathon seed becomes a “max HR 190” interval that becomes a 280 kcal snack that becomes a reason to skip dinner. This hub is the race silo on pancalc. Screening and education, not a training prescription, not sports medicine.

Energy for the day still lives in BMI vs BMR vs TDEE and calorie and macro targets. Bring TDEE with you; do not replace it with a watch’s workout tile.

Pace is time over distance

The running pace calculator solves among distance, time, and pace. Canonical seed uses a marathon-length distance (about 42,195 m in SI) and 240 minutes. Pace displays in the unit you pick; 240 minutes for 42.195 km is 5:41 per km. In miles, the same effort is a different digit — read the selector.

Self-contained answer: if the question is “what watch pace for this distance and finish time,” this is the page. If the question is “is my heart allowed to be 180,” it is not.

Splits: even pace is a teaching default. Hills, wind, and heat break it. The calculator will still divide total time by total distance; it cannot see the course.

Heart-rate zones are fractions of an estimated max

The target heart rate calculator uses age. Canonical: age 30 → estimated max 190 (220 − age, a blunt classroom formula). Moderate and vigorous bands are percentages of that max (example bands on the page: moderate roughly 95–133, vigorous 133–162 for that seed). Real max HR varies widely; 220 − age is not a lab test.

Zones do not convert to min/km without a personal pace–pulse relationship you built on easy runs. Two runners at 150 bpm can be at different paces.

Medication, illness, and heat invalidates naive zones. That is a clinician conversation, not a slider.

Steps become distance only with a stride length

The steps to miles calculator multiplies steps × step length. Canonical: step length 0.75 m, steps ~10,085 → distance ~7,564 m. A phone’s default stride is often wrong. Calibrate: measure a known path, divide by step count.

Race pace and step count disagree when you shuffle vs stride. Do not convert 10,000 promotional steps into marathon readiness.

Workout calories are a MET sketch

The calories burned calculator uses MET × weight × time. Canonical: MET 8, weight 70 kg, 30 min → 280 kcal (teaching identity, not your race). MET tables are population averages. A 280 kcal tile is not a license to eat 280 extra if TDEE already assumed training.

Self-contained rule: pick one energy story. Either TDEE with an activity factor, or sedentary TDEE plus carefully added MET bouts — not both.

VO2 from a step test is a field estimate

The VO2 max step-test calculator sketches aerobic capacity from a protocol, not from a metabolic cart. Use it to compare your tests under similar sleep and caffeine, not to brag against a lab printout from a magazine.

It does not set marathon pace by itself. Some coaches pair VO2 with race predictors; this site’s race silo does not yet include a marathon-time predictor (a listed gap). Pace still comes from the pace tool and from races you actually ran.

ACWR is load vs load, not pace vs pulse

The ACWR calculator compares acute workload to chronic workload. Spikes in the ratio are discussed in sports-science education as a context flag. They are not a diagnosis of a tear and not a green light. A low ratio with terrible sleep is still a bad week.

Do not compute ACWR from calories burned. Use the same load unit (session RPE × minutes, or TSS, or whatever you already log) consistently. Garbage in, theatrical ratio out.

Decision table

Walkthrough: Jordan’s long-run Saturday

Jordan is 30, 70 kg, aiming to cover ~10 km.

1. Pace: if the slot is 60 minutes for 10 km, pace is 6:00 /km. Use the running pace calculator with consistent units. The marathon 240-minute seed is a different race; do not steal 5:41 /km from it unless that is actually the goal.
2. Pulse: age-30 zones from the HR tool are a cap sketch for easy vs hard, not a finish-time oracle. If easy pace is 6:30 /km at 140 bpm in cool weather, heat will raise bpm at the same pace — believe pace and perceived effort before chasing a zone.
3. Steps: if the watch says ~10,000 steps at 0.75 m, distance ~7.6 km — then 10 km is not done. Calibrate stride.
4. Calories: 30 min at MET 8, 70 kg → 280 kcal. A 60 min run is not automatically 560 if MET changes with pace. Do not add 280 on top of a “very active” TDEE.
5. Load: log the session in the same units you used last month; glance at ACWR. A sudden 2× week after vacation is the plot, not the pace digit.
6. Food: breakfast grams from the energy silo. Kitchen conversion if you cook — kitchen math — not a third calorie subtract.

What not to open

Clinical calculators (IV drip, medication) are the wrong neighborhood. Ideal body weight and BMI are not race-pace inputs. One-rep max is a strength sketch for the gym, optional neighbor, not race week unless you actually lift that day.

Recording race-week numbers

Write: distance, time, pace units, HR if used, MET if used, TDEE rule (activity factor vs add-on), date. Example: “10 km; 60 min; 6:00/km; no extra MET on TDEE; 2026-09-18.” Screenshot labeled calculators. Refresh clears fields.

Limitations

Formulas here are classroom identities. They do not know your course, shoes, anemia, or heat index. They do not clear you for a race. If you are new to hard training, a clinician’s pre-participation screen beats a blog.

If a coach already gave you a lactate threshold pace, that pace is empirical. The 220 − age zone is not a way to reconstruct it. Use the coach’s pace. Use HR as a wet-bulb warning, not as a rewrite of the plan.

Second lab: 5 km in 25 minutes vs the marathon seed

25 minutes for 5,000 m is 5:00 /km. That is faster than the 240-minute marathon seed (5:41 /km). If Jordan trains 5 km at 5:00 and then jogs a long run at 6:30, those are two paces — two calculator runs — not an average of 5:45 that never happened. Averaging paces from different sessions without weighting distance is how “easy week” becomes accidentally fast.

Time-trial lab: 3 km in 12 minutes → 4:00 /km. Do not drop that pace onto Sunday’s 20 km. ACWR and tissue capacity care about the long session’s load even if the 3 km was pretty.

Calories lab: 70 kg, 30 min, MET 8 → 280 kcal. MET 6 easy jog, same time, 70 × 6 × 0.5 hours × 1 kcal conversion used on the page → 210 kcal. The 70 kcal gap is smaller than a banana. Chasing it with snacks while ignoring a 400 kcal restaurant pour is theatre.

Steps lab: shorten stride from 0.75 m to 0.65 m at the same 10,085 steps: distance falls to ~6.55 km. Race-week “I hit 10k steps” can be a shorter run than last month if you were shuffling in new shoes.

Weather, altitude, and the calculator’s ignorance

The pace tool does not know 30 °C or 2,000 m elevation. Heart rate does: pulse climbs for the same pace. If you hold zone 2 by pulse on a hot day, pace slows — that is the feature. If you hold the cool-weather pace on a hot day, pulse and heat illness risk climb. The blog’s job is to tell you those are different controls, not to give a heat index formula.

Treadmill pace vs outdoor pace disagrees with wind and grade. If you enter treadmill distance, you get treadmill pace. Do not “correct” it inside the calorie tool unless you change MET.

Taper week is the opposite of a fitness-test week. If ACWR falls because you cut volume on purpose, that is the point. Do not “fix” a low ratio with a surprise interval session the day before the race. The ratio is a descriptor, not a target to keep in a pretty band at all costs.

Packing a race bag with a calorie target copied from 280 kcal MET math usually under-shoots aid-station reality (drinks, gels, waiting in porta-potty lines). Use TDEE as the day budget; use MET as optional session color.

Grade, hills, and why MET 8 is a nickname

A flat 30-minute run at a given pace is not the same MET as the same minutes on a 6% treadmill grade. If you leave MET at 8 because a table said “jogging,” then add a hill workout, the 280 kcal seed is a nickname. Either raise MET using a table that matches the session, or ignore session calories and stay with TDEE. Do not invent 8 + grade percent as 14 MET without a reference.

Race-day elevation profile belongs in the pace plan as even effort, not even splits. The pace calculator will still spit even splits if you only enter total time and distance. Write “even effort / uneven splits” in the notebook when the course is hilly so a teammate does not pace 5:41 /km into a wall.

Heart-rate drift: over a long run, pulse rises at the same pace (cardiac drift, dehydration, heat). If you chase a zone by slowing forever, you may never hit the long-run pace you needed for the race. If you chase pace while pulse walks up, you are doing a harder session than Tuesday’s similar pace. Log both. The tools will not compute drift for you.

Track surfaces: a 10 km road loop is not 10 km on a short indoor track if you miscount laps. Enter the distance you actually covered. GPS on tight trees under-reads; a known loop over-trusts memory. The pace tool believes the distance field, not your story.

Indoor vs outdoor calibration: if you always run a 400 m track, enter 10.0 km when you did 25 laps, not the GPS 9.7 km. If you always GPS a trail, enter the GPS distance and accept pace jitter. Mixing GPS Saturday with lap-count Sunday in the same log poisons ACWR because the load unit quietly changed.

A 4-hour marathon seed is 240 minutes. If your goal is 4:30, that is 270 minutes — re-run the pace calculator; do not add 30 seconds per km by guess. 270 / 42.195 ≈ 6:24 /km. Write the new pair down so week-day 10 km work does not still use 5:41 from the teaching seed.

If you walk the morning of the race, steps-to-miles will count shopping-mall strides. That is fine for a step goal and useless as race distance. Keep race distance on the pace calculator from the course map. A shakeout jog is not the race split — do not enter it as the goal time.

Gym days are not race week, but the same person often has both tabs open. One-rep max estimates a strength session; it does not set marathon pace. Aerodynamic drag coefficient and force is for cycling or vehicle sketches, not for “air resistance on my 10k.” Keep them off the race-pace notebook unless that is actually the sport.

Practical takeaway

1. Goal time → running pace.
2. Pulse cap sketch → target heart rate, never instead of pace.
3. Pedometer → steps to miles after calibrating stride.
4. Session burn → calories burned without double-counting TDEE.
5. Aerobic field test → VO2 step; load spike → ACWR.
6. Daily energy → BMR/TDEE story, not a watch tile.

One job per lap. The % in a heart-rate zone is not baker’s percent and not VAT. Leave those silos closed until the run is logged.