Work out training impulse (trimp) instantly with clear inputs, formula shown and shareable results.
Banister's TRIMP weights duration by intensity using an exponential factor that reflects the lactate response: load = minutes x HR ratio x 0.64 e^(1.92 x HR ratio). At 145 bpm with 55 resting and 185 maximum the ratio is 0.69, giving a weighting of 2.4 and about 100 TRIMP for an hour. The exponential means hard sessions count far more than their duration alone suggests.
Heart rate ratio
ratio = (avg HR - resting HR) / (max HR - resting HR)
TRIMP
TRIMP = minutes x ratio x 0.64 x e^(1.92 x ratio)
This is an estimate from population-average equations, not a medical or diagnostic assessment. Individual results vary with genetics, training history and technique. Seek advice from a qualified coach or clinician before making significant changes to training.
Because blood lactate rises exponentially with intensity, so a linear weighting would badly understate the physiological cost of hard efforts.
Banister's original used 1.92 for men and 1.67 for women. This calculator uses the widely quoted 1.92 form.