In order for me to burn fat and loose weight, not burn my muscle off. what should i try to keep my heart rate at when i work out? i am 29 and 130lbs.

Great Question!: The fat burning range in general is between 120-150 bpm. This keeps you in a fat burning heart rate zone. Keep in mind when you are losing weight it's the food that keeps your body burning fat instead of muscle. You cannot be at a calorie count below 800 and expect to only burn fat. Nutrition (esp. Protein) is key to weight loss, with exercise and finding out if anything else is medically wrong.