If your goal this month is to lose body fat invest in a Heart rate monitor, my choice is the Polar F6.
Using your heart at the correct intensity in the activity that you are participating in is the essence to sparing muscle and losing body fat.
Training between 60-80% of your maximum rate (220-age=maximum heart rate) is key. Remember every 3500 calorie burned in this zone equals 1 pound of body fat lost.