I know I am old and two rest days work best. When I don't rest after and before my long weekend- I can't sleep, my knees start hurting and I eat... All... The .... Things. Two rest days is good.
I am running a 5k on Thursday so switched my day off to Wednesday. I woke up with that (awesome) pinging feeling in my muscles. I worked hard yesterday with an hour ride on the trainer and over an hour in the pool. I felt it- but my brain does not want a rest.
Rest days are much much harder than it would seem!!!