Very normal ! I have always had days I just want to be a couch potato and days I feel like I could enter the Olympics . On those days I just want to eat donuts all day I put on the workout clothes and usually after the first mile it gets better. If something hurts don't push too hard but I find with me it's a mental block so I push through and keep the goal of that pretty princess medal in focus !
When I first found the PHM thread in 2012 I remember someone posting you know you've almost reached the end of the race when you see the gospel choir. It either means the finish line is around the corner or you've died and gone to Heaven! It still makes me laugh!!