What bodyfat % are you at now?
Simply put 40min/day running will eat your muscle which you so dearly need when cutting. If you're losing muscle while cutting your basal metabolism will in turn be slowed down afterwards. It's a downward spiral people have to watch out for.
If it's only 15 pounds you might be better off to actually clean bulk and fat could sort itself out.
To lazy to tell you what to do read up:
www.ironaddicts.com
www.t-nation.com
Use these:
FREE: www.fitday.com
Not free: www.redpointfitness.com
"The most merciful thing in the world, I think, is the inability of the human mind to correlate all its contents... some day the piecing together of dissociated knowledge will open up such terrifying vistas of reality, and of our frightful position therein, that we shall either go mad from the revelation or flee from the light into the peace and safety of a new Dark Age."
-H.P. Lovecraft