I started training with a chest strap hrm mid march, and have noticed a consistent pattern that goes against my understanding. I’ve read that when fatigued, it’s common to have to run far slower than usual to stay under AeT. Or simply, after a hard workout run (intervals/tempos etc.), the next day on the recovery/easy aerobic effort, HR at a given pace should be higher than usual, right?
Example. If 155bpm is 9min/mile pace. The day after a hard workout, i should expect 155bpm to be slower, at say 9:30 to 10 min/mile pace. But the opposite has consistently been occurring. The run following the workout (<24 hours later), my 155bpm pace is faster than usual, down to <8min/mile. Running at 9:30min/mile pace my heart rate drops as low as high 130s. I’m seemingly running faster, whilst more easily staying under AeT, the day following a hard effort.
Two days after the workout, that 155bpm pace is back up to about 9min/mile pace, despite feeling recovered and fresh enough for another workout effort. If i don’t do a workout for a few days/week, this pace:HR ratio is maintained.
This has been consistent with 2 HRM chest straps, and over multiple weeks containing 2 workouts. I guess i’m curious as to how to pace my recovery runs, and if the faster pace post workout are still actually aerobic efforts? It’s great if they are, as i’m able to run further in the time i have, but besides not making sense, it seems to good to be true.