What should be the target heart rate during recovery phase?

[New Daddy]

What should be the target heart rate during recovery phase? One website says it should be 60%, but I can't seem to recover to as low as 60% quickly after an anaerobic phase. Does that mean I have to rest even longer to slow my heart down to 60%? Or would a higher heart rate in aerobic zone (e.g., 70%) good enough during the recovery phase?

 

[Goldfish]

There are more HIIT protocols than you can poke a stick at, each having different frameworks for recovery. When I first did HIIT, I'd do 30-45sec as hard and fast as possible, with about 3min recovery, which would have taken me back down to about 100BPM after pushing 180-190BPM in the sprint. In other protocols, I might only have 10-60sec rest regardless of HR.