I have been riding road bikes for about a year now and before that spent about 20 years riding mtn bikes. When I road mtn bikes it was more weekend stuff, never daily.
I started riding my road bike almost daily and saw a drop in my FTP this winter from 250 to about 240(I live in northern california so the winter wasn't that bad) and have been trying to build it since, but haven't had much luck. From when I got the power meter in July until mid Dec I was riding with a friend and the rides were pretty much unstructured. He had to go back to work, so since mid December I have been trying to basically do SST work and have recently (in the last 3 weeks) thrown in 2 rides with 2x20s in them at my FTP. My riding time has been cut down a bit, but the intensity has improved, yet the FTP still seems somewhat stuck (see attached chart). Right now I am trying to up my CTL and continue to add the 2x20s and SST work hoping that it has just been a lack of time in the saddle that has made a difference.
The reason I am doing all this is because in May I am going to Italy to ride for a week and follow the parts of the Giro. The rides are between 40-80 miles a day, so I want to be in shape for that trip, and I don't want to be beat at the end of each day. 2 weeks prior to that I am also doing my first century.
Any suggestions are appreciated.