^^^+1. If you want to get stronger and faster, you have to stress the system so that it adapts, and adaption occurs during recovery. The harder you stress the system, the more recovery is needed, and the older you are the more time it takes to recover. Recovery doesn't have to be sitting on the couch. Very easy rides can work well for recovery. I suggest checking out Joe Friel's books, Cyclist Past 50 and Faster After 50. They're both a bit hardcore and aimed at competitive cyclists, but the same principles apply to those with lesser aspirations.