Day 37-Back, Legs, biceps and abs/core

At the gym about an hour and 15mins. Here it is:

2 sets 2 drop sets of 8-12 reps

1. Back-PulldownsRM and Seated RowRM
2. Legs-Leg ExtensionRM and Leg CurlRM
3. Biceps-CurlDB and Narrow Grip Curl(cable machine)
4. Abs/core-25 of the following-situps with punchesDB, crunches, leg swings, kees in and out, side bendsDB, plank (30 seconds), knees to chest on the balance ball and crunches on the ball.

Finished with 15 mins fast pace on the upright cycle and full body stretch.

Am starting to work my core a bit more now rather than just focus on the abs. Want to tighten up the deep muscles around the mid section, this will prevent injuries to the spine aswell as allowing me to lift more in the long term when weight lifting, a strong core is essential for any sport, even scrabble =)