Aerobic Efficiency Index. Grade Adjusted Pace predicted at a reference heart rate from the regression line. Lower = faster. Tracks aerobic fitness over time.
GAP:HR Slope
How much faster the athlete runs per additional heartbeat, across the full aerobic HR range. A steepening slope over weeks indicates improving aerobic efficiency at all intensities.
HR Decoupling %
Pa:HR โ compares aerobic efficiency (GAP/HR) in the first vs second half of a run. Under 5% = good aerobic durability. Higher values indicate cardiac drift under sustained effort.
Regression Rยฒ
Quality score for the GAP:HR line fit (0โ1). Above 0.75 = reliable data. Below 0.5 = noisy run โ treat AEI values with caution.
ka Coefficient
Fitness response coefficient. Slope of AEI vs estimated training load (CTL). Higher ka = greater aerobic adaptation per unit of training stress.
GAP
Grade Adjusted Pace. Pace normalized for elevation change using the Minetti effort curve, so uphill and downhill efforts are comparable to flat running.
Avg Pace
Average raw pace (min/mi) across the run, not grade-adjusted. Useful for comparing run effort alongside HR in the overview chart.
ใ
Upload aerobic runs for one athlete to see longitudinal trends