The holidays can be a total diet-derailer, with all the Christmas cookies, parties and extra alcohol consumption. But if you want to burn extra calories without spending additional time at the gym, all you need to do is bump up your metabolism!

Fitness expert David Kirsch shares five no-fail ways to keep off the pounds--by getting your metabolism running at its best! How do you know if your metabolism is fast or slow in the first place? "If you're on a pretty sensible diet and you're exercising often and you don't seem to be losing the weight you want to lose, then that's a red flag that your metabolism is slower," says David.

David's Five Tips for Turning Your Body into a Fat Burning Machine:
  1. Increase your heart rate, so bump up the intensity of your workout with circuit training, intensive cardio, or wind sprints.
  2. Reduce the amount of fat in your diet.
  3. Eating smaller, more frequent, healthy meals throughout the day.
  4. Minimize the amount of alcohol consumption.
  5. Have more sex. With your increased metabolism and renewed body image that will be a result of all the changes you are making, you'll have more stamina and energy in bed. Sex is a great way to boost your metabolism!
But one slight problem, now that out metabolism is cranked up, we're hungry all the time. How do we make sure we're not overeating yet still keep ourselves feeling full? "Follow my rules," says David. "Keep your metabolism revved by keeping meals sensible and small. If you eat throughout the day, you'll never find yourself so hungry that you're overeating."