Training Load Calculator

Calculate training load (TRIMP) and acute:chronic workload ratio to monitor training stress and injury risk. Balance training intensity with recovery for optimal performance gains.

📊 Fitness📐 TRIMP = Duration × Avg HR Reserve % × Intensity Factor🏥 Health
Workout duration (minutes)
Average heart rate during workout (bpm)
Resting HR (bpm)
Max HR (bpm)
Please enter valid values.

Formula & Reference

VariableSymbolFormulaUnits
Training Load Calculator—TRIMP = Duration × Avg HR Reserve % × Intensity Factortraining load units

Step-by-Step Examples

Example 1
Hard Tempo Run

60 min run, avg HR 145, rest HR 60, max HR 185.

  • HRR fraction = (145-60)/(185-60) = 85/125 = 0.68
  • Intensity factor = e^(1.92×0.68) ≈ 3.74
  • TRIMP = 60 × 0.68 × 3.74 × 0.64 ≈ 97.5
✓ TRIMP ≈ 98 — moderate-high load
Example 2
Easy Recovery Run

30 min run, avg HR 110, rest HR 55, max HR 180.

  • HRR = (110-55)/(180-55) = 55/125 = 0.44
  • Intensity factor = e^(1.92×0.44) ≈ 2.31
  • TRIMP = 30 × 0.44 × 2.31 × 0.64 ≈ 19.5
✓ TRIMP ≈ 20 — light load
Example 3
Interval Session

45 min intervals, avg HR 165, rest 58, max 190.

  • HRR = (165-58)/(190-58) = 107/132 = 0.81
  • Intensity factor = e^(1.92×0.81) ≈ 4.71
  • TRIMP = 45 × 0.81 × 4.71 × 0.64 ≈ 110
✓ TRIMP ≈ 110 — high intensity load

Real-World Applications

🏃
Endurance Training
TRIMP quantifies cumulative training stress to balance progressive overload with recovery.
⚠️
Injury Prevention
Tracking acute:chronic workload ratio helps identify dangerous spikes in training that increase injury risk.
📱
Wearable Tech
Garmin, Polar, and TrainingPeaks use TRIMP-based metrics for training load and recovery recommendations.
🏆
Periodization Planning
Coaches use load data to structure training blocks with appropriate stress and recovery cycles.

Common Mistakes to Avoid

⚠️
Comparing TRIMP scores across different fitness levels directly

TRIMP is individualized based on personal HR zones — comparing absolute scores between different athletes isn't meaningful without context.

⚠️
Ignoring chronic training load trends

A single day's TRIMP matters less than the 7-day rolling average (acute) compared to 28-day average (chronic) — the ratio indicates injury risk, not the single number.

⚠️
Not adjusting for fitness changes

As fitness improves, the same external workout produces a lower TRIMP (lower relative intensity), requiring periodic reassessment of training zones.

Frequently Asked Questions

What is TRIMP (Training Impulse)? ▾
A quantification of training stress combining duration and intensity (based on heart rate), developed by Eric Banister to allow comparison of workouts of different types and durations.
What is acute:chronic workload ratio (ACWR)? ▾
Ratio of recent training load (acute, ~7 days) to longer-term load (chronic, ~28 days). Ratios between 0.8-1.3 are generally considered the 'sweet spot' for minimizing injury risk.
Why does training load matter for injury prevention? ▾
Sudden spikes in training load (ACWR above 1.5) are associated with significantly higher injury risk, as tissues haven't adapted to the new stress level.
How do I use training load data practically? ▾
Track your weekly TRIMP totals and watch for sudden spikes. Gradual increases (10% rule) allow physiological adaptation; sudden jumps increase injury and overtraining risk.
Are there other training load metrics besides TRIMP? ▾
Yes — Training Stress Score (TSS) for power-based cycling, session RPE-based load, and various proprietary algorithms used by different fitness platforms (Garmin's Training Load, Strava's Relative Effort).

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