This lecture will focus on the three main energy systems: ATP-CP (OPEX Gain), glycolytic (OPEX Pain), and oxidative (OPEX Sustain). We will first define, then give practical and progressive frameworks for all three systems for coaches to use with their clients. Having a simple and repeatable framework to utilize with your clients will lead to a more effective program design, no matter the goal of your client. In the workshop, we will apply these principles to ourselves to truly feel the dose response of each of the 3 energy systems.