flyingdutch said:'TRIMPS' ???
http://www.ismarttrain.com/articles/TRIMPS.html
TRIMPS = exercise duration x average HR x a HR-dependent intensity weighting factor
Since HR is related to oxygen uptake or metabolic rate (Fig. 1), the product of the first two
factors in the above equation is proportional to the amount of energy expended, or (since
efficiency is relatively constant), the amount of work performed. The third term then takes into
account the intensity of the exercise, since many physiological responses (e.g., glycogen
utilization, lactate accumulation) increase non-linearly with increasing intensity.