I’m starting a plan today after about 10 weeks of solid base. I did some lunges with dumbbells Thursday while on the road for work. I usually never do them. Legs have been wrecked. Even today, Sunday, they are sore. Needless-to-say, my FTP test (on the road) went really bad. I have to assume (read I want to blame) the lunges.
Just curious if anyone has experienced something similar? Almost 1 month ago I did 30W more 4 hours into a ride. Again just curious. These lunges are for real!
Yes. This can happen for sure if you load your legs in a way you are not used to.
A couple of months back when on vacation, and no access to a bike, I did a few hundred body weight lunges one evening for a workout. Was sore for days afterwards. Although I didn’t have access to a bike, even if I did, I wouldn’t have been able to ride it without significant discomfort.
The first time I tried walking lunges with dumbells, I was also sore for days. I do them frequently now and don’t get sore.
Add some step-ups to your lunges to hit the glutes! 
Yes those lunges did you in. I started them this fall. First few times they took their toll. Eventually you adapt .
They definitely would of impacted your test.