If you missed our first video of Dave Tate and Justin Harris, here is a short summary: Food consumed directly before a workout is less important for performance than your nutrition the 24 hours leading up to the training session. Caffeine is a reliable energy aid, but overdoing it can inhibit your training. You should be able to motivated yourself without the use of supplements.

For today's video we are continuing the series of Dave and Justin, but are turning to a new topic: the importance of GPP. Dave, coming from a powerlifting perspective, and Justin, coming from a bodybuiding perspective, offer a unique explanation of GPP and why it matters. Dave begins by first showing that the definition of GPP is entirely dependent upon the sport of the athlete — it means something different for a high school football player than it does for an elite powerlifter. He describes it in one sentence: "GPP is your ability to increase your aerobic capacity to a level that allows your body to recover and replenish nutrients effectively."

Dave also points out that as a lifter gains weight, aerobic base often begins to fall, which reduces the body's ability to recover and utilize nutrients. When this happens—and you will know when it does—you need to add some form of GPP work into your training.

Justin follows Dave's response by discussing how increased cardio work, particularly high-intensity interval training (HIIT), can allow a lifter to more effectively utilize the calories he or she consumes. Regularly performing this HIIT work increases not only metabolism but also training endurance, which then allows you to push harder during high-rep sets and induce more muscle growth. It also helps your body learn how to process and assimilate a large amount of nutrients, which is key to the growth of any bodybuilder.

WATCH: Sources of Pre-Workout Energy with Justin Harris