It’s kind of a mix of all of that. So you just slowly want to increase the amount of sweet spot you do each week in a weekend ride. Can start with a total of 40 minutes and work up to 90 minutes or even 120 minutes based on your goals and ability.
If you live somewhere with lots of climbs, ride the climbs at sweet spot which is a great way to do it! Just going from bottom to top so you don’t have to look at the time. Like in the training tip on how to sweet spot in a group ride take longer pulls, stay on the front, or off too the side so you are riding at sweet spot.
If the group ride is slower and you are mostly zone 1,2 during it and you don’t want to disrupt it one thing I would do is a 15 - 20 minute sweet spot effort before and or after. Just to make sure I would get my sweet spot training in.
The idea behind the group sweet spot is not having to look at your timer and being a drone. Some people get burnt out so easily on specific training repeatedly so nice to have this little break and using a group to get the efforts in. Look at the TSS and try to match up with that.
Also during the group ride look to have an intensity factory of .84 - .96 That would be a sweet spot average overall.