I completely understand! I took over a year off when I had DS. I tried riding last summer and I was so slow and fatigued. I couldn't keep up with people I used to leave in my dust.

I did a lot of conditioning over the winter: Intervals, plyometrics, core strength training (mostly plank, side-plank), and a ton of lunges and isometric squats. It's made an unbelievable difference. I'm a stronger cyclist than I've ever been.

Hang in there, mix-it-up. It will come back. It just takes time.