395 floors or so at level 5 on the #StepMill today. Not the longest, farthest or hardest I've ever gone, but I'm grateful that my Achilles has recovered enough that I can do workouts of more than a #VerticalK again.

Not sure what's going on with that cardiac drift at about 90 minutes in, though. Maybe an energy substrate change? I think the room was cool enough that thermal issues shouldn't have been a factor.

#cardio #endurance