You have to mix it up a bit. If you do near enough the same stuff every week your body will get used to it and you will gain some fat back!!

Do more reps, less weight, more different exercises. Keep your heart rate up. Use free weights and cables early on but as your body gets tired use machines to finsih yourslef off. Be really carefull with your form. Maximum concentration on your movement both as you move the weight and as you realese it.

Get some swiming in there too. If you can find somewhere that does pool based circuit training do it!!