Another point perhaps pertinent to this discussion is that, IIRC, Seiler does not talk at all about diet required to maximize this type of training. IOW, eat whatever makes you go.

Chapple, in Base Training for Cyclists, says that this low intensity training stimulates fat burning. Unless I am mistaken, always possible, fat is the only energy source which does not generate lactate and Seiler says that the response to this large volume of base is to reduce blood lactate levels at base intensity, which then would mean the same thing Chapple is saying: increase the fat burning percentage of the various energy sources.

So does this mean we don't have to go out for base training with only water in our bottles to increase fat burning? In fact does what we consume before and during exercise matter at all as long as it's calorie appropriate and meets our body's needs, as long as we obey the dictum to stay under VT1?