You can burn fat while you sleep.

Now that I have your attention, let me clarify - there is a catch. If you want to burn fat while you sleep you need to work hard while awake.

It’s not just about working hard, but more about working efficiently to get your fat-burning machine rolling. So how do we burn the midnight oil (or fat) while sleeping?

You may be surprised, but it doesn’t happen by running for hours on the treadmill, elliptical trainer or stationary bike. While cardio endurance training has its place in the world of fitness, it is not ideal for maximizing your fat-burning potential.

Long periods of cardio training can actually trigger the body to burn lean muscle for energy. Sure, you are burning calories (energy), but there is a difference between burning calories and burning fat.

If your goal is to burn fat, tone up and create a shapely body without sacrificing lean muscle mass, you need to increase your resting metabolic rate (RMR). The RMR is the amount of energy your body burns while at rest. If you are able to boost your RMR, the fat burning process will continue even after you step out of the gym.

The answer is to shift towards more anaerobic interval training where you perform a series of high intensity exercises followed by short rest periods. Various studies have shown that this type of training not only increases aerobic capacity, but also burns more fat over a 24-hour period than traditional endurance training.

There are a number of ways you can stack exercises into metabolic circuits, but one of the simplest ways is to use a Tabata circuit.

Tabata is simple; perform an exercise for 20 seconds followed by a 10 second rest period. Repeat this eight times for a total of four minutes. Because the exercises are performed in short 20-second bursts, it is important to go 100 percent. Give it a try at the end of your next workout with jump rope, going all out for those 20 seconds of work. This may be the most intense four minutes of your entire workout.

Try a kettlebell

The way I see it, the simplicity and versatility of kettlebells make them the perfect tool for this type of training. Kettlebell circuits are perfect for boosting metabolism and burning fat without sacrificing lean muscle mass. For those looking for more of a challenge, string four or five tabata “mini-circuits” together and run through them back-to-back for a 16 to 20 minute workout. Here is a sample workout of kettlebell exercises that you can stack in four-minute intervals: Swings, clean and press, front squats, snatches.

Whether you use kettlebells, barbells, dumbbells or body weight, I recommend choosing full-body exercises to get more bang for your buck. Using more muscles allows you to increase intensity without risking overuse injuries to one particular muscle or joint. You will be burning fat while building lean muscle, which will keep those arms, legs and buns toned.

This type of training is very intense and really gets the heart pumping. You should consult a physician or other fitness professional before training and start at the level that is right for you. Once you have a clean bill of health, grab a kettlebell and a stopwatch, get creative and have fun.

These workouts will wipe you out, so be prepared for a good night’s rest.

Todd Gilchrist is a personal trainer and kettlebell specialist at Powerfit Personal Training in Rohnert Park. He can be reached at todd@powerfitusa.com.