When I first heard the term Excess Post-exercise Oxygen Consumption I thought it was talking about Body'Fit pH Fitness exercise or pHx. Not so. E.P.O.C. refers to the default oxygen consumption that occurs from accumulating an oxygen deficit, which occurs during the anaerobic phase of any workout. Whereas pHx actually increases the amount of oxygen availability by engineering a higher rate of oxygen absorption in both the lungs and tissues enabling 100% aerobic metabolism.
The reason the word 'excess' is acceptable terminology for oxygen consumption during E.P.O.C. exercise is because many processes in the body make a claim on any and all available oxygen. These include hormone balancing, replenishment of fuel, cellular repair, cardiovascular conditioning and rebuilding of muscle cells. Oxygen is also required to convert lactate resulting from anaerobic metabolism into glucose, and of course the increase in metabolic rate during and after exercise demands more oxygen as well.
The body switches to lactate or anaerobic metabolism within a few minutes (almost immediately during E.P.O.C. exercise) because it runs out of oxygen. This causes chemical changes in the blood that need compensation, otherwise homeostasis isn't restored. Without building oxygen reserves with pHx pre and post an E.P.O.C. workout, recovery can take several hours if not days before the kidneys return the pH balance of the body to normal.
By itself the more rapid breathing triggered during exercise can't produce enough oxygen to accelerate this process. On the other hand, the oxygen fulfillment of each movement is so efficient with pHx the usual hyperventilation that occurs at the Respiratory Compensation Point (RCP) is never necessary, not at any degree of performance speed or intensity. There is no oxygen debt ever.
So with E.P.O.C. exercise we're looking at excess oxygen consumption, but not a lot of excess oxygen. Since the muscles pull most of the blood out of the body during E.P.O.C. the rest of the body is not usually metabolically active. This is the fundamental difference that makes pHx an ideal warm-up cool down for E.P.O.C. Muscle mass is about 30 percent of total body mass at most, so when pHx makes more oxygen available to all the tissues of the body, overall metabolic rate increases, consuming more oxygen and burning more calories than muscle tissue can with E.P.O.C.
In summary, more oxygen availability means more oxygen consumption. The benefits of building oxygen reserves as opposed to an oxygen debt during exercise are readily apparent as soon as you begin to warmup with pHx before E.P.O.C. workouts. Optimizing oxygenation makes a big difference in energy, recovery, and results.
