I think many are misinterpreting Andy Eggerth’s great powerpoint notes on what is truly going on with PH disruption in training, claiming that doing energy system training is going to be the same as bodybuilding or drinking a postworkout shake. So where does the research and coaching observation lead us? Dan Pfaff is still doing lactate profiling, a method that is clouded in secrecy in some circles due to the record keeping in the 1980s. One prominent coach elaborated that 12 bouts of specific intensities above 90% with rest periods of 3-5 minutes creates some unique physiology, creating a cold war of interest between countries in getting 14,16, and 18 repeats. Bleed runs are submaximal but intense repeats that expect the same times while increasing the acidosis level of the body due to the slightly abbreviated rest periods. While I can’t comment on the exact cause and effect, saturating the body with more PH disruption with the same work output does help with speed endurance.