EPOC (Excess Post-exercise Oxygen Consumption) and TRIMP (Training Impulse) are used to quantify training load. They accumulate exponentially to training intensity. The key difference is that EPOC decreases during the recovery breaks while TRIMP only accumulates upwards. Also, EPOC is scaled in Training Effect (0.0-5.0) helping the interpretations while TRIMP scores don’t have automatic classification.
You can read more about the Training Effect, EPOC and TRIMP from here.
See also the video about EPOC from here.