I have just started the sweetpot 18 week plan. The thing i am unsure of is i am using HR Tss because i do not have a power meter but i have noticed that when i convert a workout in Training peaks from power to threshold heart rate. It drops the tss for that workout. For example endurance zone two 1hour 30 mins is 75 tss but when i change it to threshold HR it becomes 58 Tss. so should i be aiming for 58 or 75. I know more is usually better. But am i doing enough if i only hit the 58. I have just done the said workout at a reasonable pace and got a tss score of 67.
Many thanks in advance Phil