Trashcan Annie

I like that "I want 70 mpw to be the new 50" that's is what I want too.

Hey, that's cool, I want my easy paces to be 7-7:30 too! Looks like we have similar goals, heh heh.

Good idea to slow the pace down. I would take it down even further - 7:30 - 8:00. Think of an aerobic run as a pleasant walk in a forest. You should also back off on the track workouts until every part of your body starts liking the new volume.

There is a good reason for the above. Aerobic endurance is being built at about the same rate per mile once you get your HR above 60% of the max or so. I suppose you would gain a little bit by going faster, but not very much. However, the muscles/bones will freshen up at slower paces, but tire out at faster paces. Same for the nervous system. Your aerobic run pace should be no faster than the slower freshen up/wear out threshold of the muscles and the nervous system. Perhaps 1% of elite runners are made of steel, and might still be able to freshen up both subsystems at paces approaching their marathon race pace. But most will be limited at least by one of the two in how fast they can go on their aerobic runs productively. E.g for me, the muscles could probably handle the whole 120 miles a week at 6:00 pace, but the nervous system starts gradually wearing down once I start running faster than 7:00. For you it is probably the other way around - the nervous system could handle 6:30 pace, which is why you are antsy to go this fast, but the muscles start breaking down at around 7:30.

I believe there is a truth to that philosophy that should not be ignored. However I don't agree that training should always look like this. I think key cycles should, but in general, I think too much slow running=slow running. After all we are not only training our circulatory and respiratory systems but our muscle response as well. From my experience, it's all about listening to the body, and most of the time 6:40 pace does feel like a walk in the forest to me. I just know that in order to keep up my track workouts while increasing volume I have to back off my easy pace for precisely the reasons you mentioned. Once I adjust (eg my muscles accept the new volume), I plan on decreasing my easy pace again, if it feels good, and so on until my body is ready for another increase in volume.