While it wasn't obvious to me at the time (??), my HM training has really slowed me down.
Good news though- I'm back to under 6min/km and the adage "you've got to slow down to speed up!" is running through my mind as I hit the treadmill for speed session #1.
Warm Up: 5mins @ 9.0km/hr; 6x30s @ 12.0km/hr w 30s rest
Main Set: 500m @ 11.0-12.0km/hr with 250m @ 9.0km/hr
Warm Down: Pyramid jog/run/jog 9.0-9.5-10.0-10.5-10.0-9.5-9.0km/hr; 1km walk