Billat 30-30’s with Xert, Vo2Master, and PerfPro
Billat 30-30’s Are a Great Way to Improve Your Ability to Suffer Under Load! Xert has zones that flex with time spent above Threshold. When you bite into HIE, the Xert Dial responds by reducing the band of yellow or orange, and expanding the Purple arc, which is theoretically not possible to surpass. When […]