Its a good course to highlight rider strengths. I was a little quicker than Paul on the flat by a minute and Paul was 2 mins quicker up Keith (rounded numbers).
My power numbers were Sweetspot range, but with bursts to stay with my group or try and go with a faster group. I was pleased with my endurance and gradual power increase whilst climbing Keith.
Im coming to the end of this training block and will begin to add in shorter mid time intervals for increased power- mostly Sweetspot though
Blasting out the blocks to get ahead of the slower riders, then settling in to a group (or a snake depending on how many riders tonight) works for me. Once you're in a group drafting it takes such a massive effort to break that group draft and get into the next group that I'd go into the red and maybe not then be able to hold the next group. I try to hold on at 2.6/2.7 w/kg and do the few bursts as needed to stay in that group, or follow those who try to break away.
If a faster group comes from behind I will increase power just before they overtake me to try and latch on to their wheel. Same on little inclines, burst of power to stay in the group.
Quite a few articles on power needed to stay in the drafts in Zwift; if someone pushing 3.0 (for e.g.) you can likely stay in their draft only pushing 2.6, but will also stay in their draft pushing up to 3.0. So I always aim for the lowest effort for the most gain. To break their draft and progress I'd need to push 4.0+ for some time and even then, if I was in a blob originally, they'll likely catch me back up again. I might as well cruise at 2.6 than burn too many matches for no real advantage.
I find hills though are totally different - this is where the w/kg kicks in and everyone starts to pull away from me. Those I can draft behind on the flats suddenly leave me for dust. When I get to Keith I'll need to keep something back so I can aim to climb it close to 3.0+ w/kg.
I never win races, but sticking to these tactics always sees me finish, get the odd PB, and sometimes increase my FTP