Rickey Pack asked the question on FaceBook during the Warrior Diet interview:

"What does the speaker think about exercising while hungry?"

Exercising intensely (resistance/sprinting) while fasting has a notable biological advantage: It forces your body to increase adaptability to hunger/fasting. Meaning: Your body gets more efficient in converting fat and glycogen stores to energy. Recent study has shown that exercising while fasting yields a greater fat loss than exercising after a meal. But the greatest advantage of this regimes is that it INCREASES your muscles capacity to absorb protein from your recovery meal (as compared to training after a meal). This means that training while fasting POTENTIATES a greater anabolic impact as compared to training after a meal

But all that said, I’m still against training while totally fasting.

Here is why:
Total fasting affects maximum performance. It will certainly slow you down and compromise your strength. So to prevent that, I recommend to have a light whey protein meal about 30 minutes before training. This puts your body in a win-win situation. It provides you with all the advantages of training while fasting But without compromising on performance.

Furthermore, both resistance and sprinting are primarily non aerobic drills and whey protein provides the ideal fuel for such drills. Hence, it provides BCAA for glyconeogenesis  which is the most efficient fueling system for non aerobic exercise.

But note again that the pre-exercise whey meal must be made without sugar or carbohydrate added since these could shut glycogenesis and negate all the above advantages of the whey meal. Finally, the pre-exercise whey meal regimen applies to all kinds of fasting before intense non-aerobic drills.