Use the toggle top-right to switch between two views of the same block. Aerobic capacity plots your Efficiency Factor — distance per heartbeat at easy effort, shown ×100 (so 121 ≈ 1.21m per beat). It's heat-adjusted and smoothed over 4 weeks, and rises as your aerobic engine improves — roughly 100 for a beginner, 160+ for a fast club runner. The shaded band is the middle 50% of your individual easy runs that month (25th–75th percentile) — a narrow band means your easy days are consistent, a wide one means they're scattered. Goal trajectory (when your block has a time goal) shows Coach Miles' prediction of your race time today as a 3-week median, descending toward the dashed goal line. A flat or dipping stretch during a hot spell or hard block reflects fatigue or conditions, not lost fitness.
These are your current target paces, worked out from your fitness rather than a fixed table. Your best recent hard effort (a race, parkrun or strong tempo) sets the quality paces, and your everyday training keeps them moving between races. With no hard run yet, they're estimated from your heart-rate data (tagged estimated) or your logged efforts (provisional), and they sharpen the moment you run something faster. Coach Miles reads the same numbers, so the tab and your coach always agree. The spectrum under each band shows where it sits from fast to easy; the badge shows the trend, where ▼ down means you've sped up. Everything updates live as you sync.
Based on your max HR.