How do I improve my running cruising pace? Ask Coach Parry 20

Today’s question comes from Warren Kidgell:My training is going pretty well so far, but there is a long way to go. One thing I’m grappling with is the idea around how to improve cruising pace for the Comrades Marathon. A key session you have in your schedule is the 8km TT. To me I consider this to be a threshold run, so run at about 15km race pace, barring a complete blow out once a month where you give it your best. What are your thoughts around replacing this with a longer tempo to marathon pace type session? Something like 16km at MP? I find this a great session and although the pace is somewhat slower (I’ll run threshold at 3:35/km and MP at circa 3:50/km), I find that it is a great session for marathon training. Which session is better geared towards Comrades prep in your opinion? My thinking is to do the longer session more often but still throw in the 8km once a month or so.