My bike wheel wore out. It wobbled. It was more work that it should be to pedal. I replaced it with a new one. That's much easier to pedal.

I don't mind the Superman feeling of my leg muscles being plenty strong for pedaling. That's going to fade if the muscles aren't used though. And I do notice the muscles are being fatigued in a different way. It's easier to pedal, so I'm probably on a higher/harder gear pedaling now.

If I wanted to make it more difficult to pedal again for the purpose of pushing those leg muscles a bit while I'm doing my normal riding.... Is there an attachment or something I could use on the bike that would do that? I went a long time with that extra 10% or whatever amount of work pedaling. I did notice it sometimes, but mostly it was hidden in my normal commute riding.

Is there anything I could add on my bike that would recreate that, make it harder to pedal?

I remembered an old exercise bike having an attachment like this that regulated the amount of work needed to pedal.
http://images1.americanlisted.com/nl...d_30658103.jpg

Would there be anything like that a normal bike? Except I've got splash guards over my wheels so this would quite work.