Legs of Lead

I'm in the 10th week of my program. The first 4 were actually a bust because of health reasons so I consider this week 6. WOW, Mommy never told me it would be like this! I'm fatigued with heavy limbs and I can't get enough sleep. The good news is my RHR is as low as it has ever been. I'm really having to dig deap just to even look at my bike let alone get on it and ride.
Today's workout includes several Power Intervals and the instructions say it can be good to do those inside on the trainer. That will help me get going.