Originally Posted by
Tombaatar
I commute to work as much as I can. Lately it has worked out to be every day but one a week. 12 and a half miles each way. On Sunday I will ride 35 to 45 miles. Come Monday morning, I'm beat. Legs tight and tired. Question is. Should I rest or ride anyway? I want to ride but I don't want to tear my muscles down. I'm 50.
Youngster

I'm in a similar situation and commute 40 mi round trip during the week. I usually do a group ride on Sat and maybe an easy ride or nothing on Sun.
I vary the intensity of weekday commutes depending on how I feel. If I'm fresh I'll naturally go harder. If I do a big ride on Sunday, I'll take it easy on Mon. If you're tired on Mon treat that day and maybe the next as a recovery day and just ride slower to work. A recovery ride isn't going to damage anything.