Running Pace, One-Rep Max (1RM), Target Heart Rate & Calories Burned Calculator

Compute running pace & race splits, Epley/Brzycki 1RM strength max, Karvonen HR zones, and METs energy burn.

Running Pace & Epley One-Rep Max (1RM)
5:00 /km • 1RM: 93.3 kg
Speed: 12 km/h • Aerobic Zone (70–85% HRR): 151–171 bpm • Burn: ~720 kcal
Running Speed 12 km/h
1RM (Epley / Brzycki) 93.3 kg / 90 kg
Karvonen Zone (70–85%) 151 – 171 bpm
Estimated Calories Burned 720 kcal
Inputs
⚡ Scenarios:
km
Distance in kilometers (5K = 5, Half Marathon = 21.0975, Marathon = 42.195).
minutes
Total elapsed time in minutes.
kg / lbs
Submaximal barbell or dumbbell load lifted.
reps
Clean repetitions completed before failure.
years
Used for 220 − Age maximum heart rate estimate.
bpm
Morning resting pulse in beats per minute.
kg
Used in the Compendium of Physical Activities METs equation.
Results & Graph
Running Pace & Epley One-Rep Max (1RM)
5:00 /km • 1RM: 93.3 kg
Speed: 12 km/h • Aerobic Zone (70–85% HRR): 151–171 bpm • Burn: ~720 kcal
Running Speed
12 km/h
5K: 25m 0s • 10K: 50m 0s
1RM (Epley / Brzycki)
93.3 kg / 90 kg
Karvonen Zone (70–85%)
151 – 171 bpm
Max HR: 190 bpm
Estimated Calories Burned
720 kcal

Projected Race Finish Times at Current Pace (Minutes)

5K, 10K, Half Marathon (21.1 km), and Marathon (42.2 km)
Graph 1 • 5K, 10K, Half & Full Marathon Finish Projections Constant-pace finish time timeline
5K Road Race (5.0 km) 25m 0s 10K Road Race (10.0 km) 50m 0s Half Marathon (21.1 km) 1h 45m Full Marathon (42.2 km) 3h 31m
Graph 2 • Karvonen Heart Rate Reserve Training Zones (Z1 to Z5) THR = Resting HR + (Max HR − Resting HR) × Intensity%
Zone 1 • Active Recovery (50%–60% HRR) 125–138 bpm Zone 2 • Aerobic Base & Fat Oxidation (60%–70% HRR) 138–151 bpm Zone 3 • Tempo / Aerobic Endurance (70%–80% HRR) 151–164 bpm Zone 4 • Lactate Threshold (80%–90% HRR) 164–177 bpm Zone 5 • VO₂ Max Anaerobic Peak (90%–100% HRR) 177–190 bpm
Graph 3 • Barbell Working Weights by Target Repetitions (1RM to 12RM) Derived from your Epley One-Rep Max
0 kg 50.4 kg 100.8 kg 1RM (100%): 93.3 kg 93.3 1RM (100%) 3RM (92%): 85.9 kg 85.9 3RM (92%) 5RM (86%): 80.3 kg 80.3 5RM (86%) 8RM (79%): 73.7 kg 73.7 8RM (79%) 10RM (75%): 70 kg 70 10RM (75%) 12RM (70%): 65.3 kg 65.3 12RM (70%)
Summary: Pace is 5:00/km, 1RM is 93.3 kg, and Karvonen 70-85% HR zone is 151-171 bpm.
Summary: Covering 10 km in 50 minutes requires a pace of 5:00 per km (12 km/h), burning approximately 720 kcal at 70 kg body weight. Lifting 80 kg for 5 reps corresponds to an estimated One-Rep Max of 93.3 kg (Epley) or 90 kg (Brzycki).
⚡ Send result to: Calorie & TDEE →BMI →Body Fat & LBM →
Interactive chart & math engine powered by CalculatorGraph

Formula & Mathematical Methodology: Epley/Brzycki 1RM, Karvonen HR Reserve & METs Expenditure

1RMEpley = W × (1 + Reps30),   THR = HRrest + (HRmax − HRrest) × Intensity%
Calories (kcal) = METs × 3.5 × Wkg × Minutes200
1RM_Epley = W × (1 + Reps/30); THR = HR_rest + (HR_max − HR_rest) × Intensity%; kcal = (METs × 3.5 × Weight_kg × Min) / 200
  • HRmax − HR_rest: Heart Rate Reserve (HRR) in beats per minute
  • METs: Metabolic Equivalent of Task (1 MET = 1 kcal/kg/hr resting)

Rounding: Pace rounds to nearest second; weights round to 1 decimal place.

Worked Example: 10 km in 50 Minutes + 80 kg Lifted for 5 Reps (Age 30, Resting HR 60 bpm)

Compute pace, race splits, 1RM, and aerobic heart rate zone.

  1. Pace = 50 ÷ 10 = 5:00 /km (12.0 km/h speed; Half Marathon pace projection = 1h 45m 29s).
  2. Epley 1RM = 80 × (1 + 5/30) = 93.3 kg; Brzycki 1RM = 80 × (36/32) = 90.0 kg.
  3. Karvonen 70%–85% aerobic zone = 60 + 130 × [0.70, 0.85] = 151–171 bpm.
Result: 5:00/km pace, 93.3 kg Epley 1RM, and 151–171 bpm aerobic HR zone.

Frequently Asked Questions

Why is the Karvonen Heart Rate Reserve method better than a simple % of Max HR?

Because Karvonen accounts for your resting heart rate, an indicator of cardiovascular fitness, rather than assuming all people of the same age have the same working heart rate range.

Health & Fitness · Endurance & Strength Training

Running Pace, One-Rep Max (1RM), Target Heart Rate & Calories Burned Calculator: inputs, method, and how to read the result

Compute running pace & race splits, Epley/Brzycki 1RM strength max, Karvonen HR zones, and METs energy burn.

Choose inputs for the case you are checking

The defaults are illustrative. Replace them with values for your case and keep the units shown beside each field.

  • Run Distance: Distance in kilometers (5K = 5, Half Marathon = 21.0975, Marathon = 42.195).
  • Run Duration: Total elapsed time in minutes.
  • Weight Lifted (For 1RM): Submaximal barbell or dumbbell load lifted.
  • Repetitions Completed (1–30): Clean repetitions completed before failure.

What the calculation includes

With the default values shown, Running Pace & Epley One-Rep Max (1RM) is 5:00 /km • 1RM: 93.3 kg. The calculation follows Epley/Brzycki 1RM, Karvonen HR Reserve & METs Expenditure; the formula and variable definitions above show how the inputs combine.

One-input check: With the other defaults held constant, changing Run Distance from 10 km to 11 km changes Running Pace & Epley One-Rep Max (1RM) from 5:00 /km • 1RM: 93.3 kg to 4:33 /km • 1RM: 93.3 kg. This is a comparison inside the calculator's stated model, not a prediction.

Where to use caution

  • Race split projections assume constant flat-course pace (for marathon distance, Riegel’s 1.06 fatigue exponent typically adds ~6% per distance doubling).
  • 1RM equations are most accurate for sets of 2 to 10 repetitions.

Scope: Global Sports Science Standard Check the assumptions and limitations against your situation before relying on the estimate.

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