From my personal experience, running long distances might not help much at all. Now if you were to sprint those 2-3 miles, it'll help. But jogging doesn't cut it I'm afraid. Best thing in terms of cardio to do is do loads of sprints.
In terms of sit ups, don't cheat with the weights. I see plenty of guys in the gym grabbing a plate and holding it across their chest. Doesn't do crap, anyone can go up and down with two 45's across their chest. It's too close to the center of rotation to offer anything. If you want to really make them work, hold the plates over your head.
And on the medicine ball sit ups, have the guy throw the ball to you right when you are about to come up again. In addition have them throw the ball right over the top of your head.
Lastly, just change your diet a bit, less carbs and eat throughout the day so your metabolism upped, allowing your body to burn calo's all through the day.
Now personally, I hate running, I'd rather do anything but running. So in order to get my cardio in, I usually play basketball or some other cardio intensive sport. Hard to get any wrestling in since you can't just go to a local park and hop on a mat. I suck in basketball, but when I'm on the court, I concentrate on just sprinting back and forth on the court, go after every loose ball go nuts on defense and all the other stuff those glory seekers/cherry pickers hate to do.
So the best way for you to stick with the program is do something... FUN.
edited for spelling.. big to bit...