Housework makes me tired!

When I'm at work (I job share so I work a week, then have a week off, then work a week etc) I'm busy all day non stop and I'm fine, no problems.

Yet on my days off when I can get myself motivated to do anything around the house, I seem to get tired quite quickly!

Anyone know what I mean? And what can be done about it?:confused:

Housework makes me tired!