P90X --I took a break, but I'm back

OK, so I didn't even finish 1 week of P90X before taking a break. But, I'm back now.

Today, I did pullups and pushups for 1 hour (Chest and Back). I was grunting at the end, so I'm pushing myself pretty hard, right? Then it was "Ab Ripper X", which is not getting any easier. The oblique exercises are just killing me. This was the worst session yet.