80/20 Running: Run Stronger and Race Faster by Training Slower

by Matt Fitzgerald

Start by doing either a thirty-minute time trial, a perceived effort–based test workout, or a talk-test workout to determine your lactate threshold heart rate, then calculate your five heart rate training zones using the percentages in Table 6.1. Use one of these same workouts to calibrate your perceived effort ratings, anchoring your lactate threshold intensity to a perceived effort of 6 on a 1 to 10 scale. Determine target pace ranges that correspond to your five heart rate zones either by finding the pace that corresponds with the heart rate marking the low end and high end of each zone or by using the McMillan calculator. Use perceived effort to establish your initial intensity whenever a workout calls for a change in intensity. Use heart rate as your primary intensity metric in all low-intensity runs (Zones 1 and 2). Use both heart rate and pace to regulate intensity when running at moderate intensity (Zone 3).