Setting HR Zones Based on LT1 and LT2

Zone 4 corresponds to (anaerobic) threshold which is LT2. I think your LT2 should land squarely in the middle of zone 4. 

In addition to what cf8d262a821f4ca293edb5877584c839 said, I would put LT1 as the lower limit of zone 2. So the left column would contain the following values

XX (you can put any value, mildly higher than your RHR, for example RHR+10 - it doesn't really matter)

132 (LT1, which is 76% of your LT2 - Joe Friel recommends 80% for start of zone 2, so 76% is ideal )

155 (90% of LT2)

163 (95% of LT2)

182 (106% of LT2 - note that LT2 @ 172bpm is the average between bottom limit and upper limit of zone 4)

188 (upper limit of zone 5 is your MHR)

If you train using HR, you could also set up your heart rate zones to eliminate zone 1, and insert a sweetspot zone to cover the 95%-99% range of LT2. In that case your zone 4 would start at 100% of LT2.

My recommendation is to train with power, and to incorporate the sweetspot zone in your power zones, rather than in the heart rate zones (because HR lags anyway).