R u doing cardio or just toning
Twisting (Russian) situps, oblique crunches, and side planks are all great for targeting your oblique muscles. I found some great exercises for your oblique muscles at ab-workouts-guide.com under situps, crunches, and planks. Try Multi-Plank Challenge2, Min Full Plank Challenge, 15 Min Core Booster Abs they're short intense but well worth it. Good luck and God Bless.