I usually get sore only when I make a big change in the workout regimen. 
I row my shell about an hour a day, and when forced to, I row my egrometer for at least a 1/2 hour, (6 out of 7 days anyway). 
But when the lake gets ice covered, and I put my shell up for the winter, I decide I must go hit the weight room again, so last two weeks in November I am usually pretty sore. 
For me it is bicep, pecs, calfs, and quads that get sore most, but those are used more in the weight room than the boat, so I think that is why those groups get sore for me.
When I bump the time and /or speed up on the rowing machine, it seems more like a dull overall ache, but it usually is not present the next day.  I feel some lactic build in the quads as I climb stairs, but it is just present, not painful.  Aerobic workout on the bike shouldn’t be painfull. 
A sore back may mean you are using improper form, so be careful. 
I take a very hot shower and sauna before and after weights and that seems to help.