So we went out today and did a "group ride" on our tandem, except that we left about 15' before the group. I redid my zones using Friel's 7 zone system in TrainingPeaks. We tested Friel's zone 2 to see if it accurately predicted VT1. It seemed to both of us that it did. Right at the top of z2 our breathing rate would increase noticeably. We kept our HRs and thus breathing below VT1 the whole ride, except for a couple spots where we did a little z5 to see what that was like, and a few hills that we simply couldn't get up below VT1 and had to go a couple beats over.

It was a little weird to climb so very slowly, but being a tandem we could make up for a lot of that on the flats and descents. We stayed ahead of the group for the whole ride. 32 miles and 1850'. Very nice and interesting ride. We'll do more of this. It's fairly obvious that is one is going to train this way, one only needs the 3 zones, and one tries to never ride in the middle one. I'll try to report back in a few months, if I remember . . .