So I've took up and read Hadd's training principles and it seems pretty solid for me. This week i tried it and realized how horrible my endurance is... i dont even want to post my pace. It feels like I'm actually almost walking. I try to stick around 140 to 145 bpm, its hard though because how slow im going. (I use a chest strap so i know this is accurate)Any advice on this? Also can someone give more insights and their experiences with Hadd.