For a little while now I am using the triathlon plans for duathlon purposes - and I think it works quite well. In fact, I invite you to try it out.
A bit of backstory: Pre corona-crisis I was pretty set on competing in my first triathlon but never really warmed up to swimming. The logistics of driving to a pool and wasting time in my car compared to just heading out of the house and starting a run or bike ride always seemed like a hassle. Plus, I am apparently not the most social person and always had to deal with other people, crowds and whatnot.
Since the end of february all pools in my area were closed and I decided to just skip the sessions but keep the training plan.
I now prioritize additional strength training by doing it on all the scheduled swim workouts - and absolutely love it this way. I am just careful not to overdo the leg work before a tough session.
My two cents: Try a triathlon plan and screw swimming, or do it every once in a while as a complimentary session. Maybe you have another complimentary sport you would like to squeeze into the calendar instead. This way your bike and run workouts are all made in the same place and work very well together.
I use garmins firstbeat technology to log all my exercise and according to the data my training load is spot on all the time.
My hope is the Sufferfest will keep broadening their overall offerings and throw in a bit more variation for the running workouts. Right now they are good, but, of course, you can feel that they are not the prime interest of the program.
@SUF Team: My absolute dream would be a scalable duathlon plan - with strenght training sessions and yoga. But for the strenght training I like to consider individual days and not just additional slotted in workouts. While I like the offered strenght training in the app, I much prefer my own bodyweight and barbell routine. (Sorry to hijack the thread a little bit).