I have been cycling for just a year now and I am in my mid 40s. After about six months of steady gains I was no longer progressing. I have been using trainerRoad since I started. After about six months of just getting tired and seeing no improvement I bought the Sweet Spot 3 program. For the first time in a while I am seeing gains (about 7% from the field test results).
My only negative feedback would be that I had a hard time choosing between low and mid volume. I chose mid volume but had trouble with time the last week or so as the rides became longer. Thanks for a great plan. I will definitely be buying another one soon.