Almost any exercise has fat burning potential if you do it at the right intensity. If you’re planning a workout, however, certain combinations can maximize fat burning and give you the most benefits for your effort. No matter how much time you have available for a workout, there are still things you can do to improve your routine.

If You Have 15 Minutes

Set up an interval circuit routine that combines cardio and resistance exercises. Forget free weights –You’ll spend more time picking them up and putting them down than you will actually spend actually using them.

Instead, opt for exercises that use your own body weight, such as pull-ups, push ups and triceps dips (done on a chair edge). Do 10-15 repetitions of one exercise, then stand up and jump rope or do jumping jacks for 3-4 minutes. Then repeat it all over again with a different strength exercise.

If You Have 30 Minutes

Add an abs workout to the mix. Do at least 15 reps of a single crunch or combine a series into a 3-4 minute superset. With 30 minutes available, free weights become an option. Stick to a pair or two of dumbbells (so you can alternate weights for different muscles or sets) rather than using ten different pieces.

If you’re working out at the gym, jump on the treadmill for a quick 10 minute run before you do your weight training. Then spend 7-8 minutes on weights and then back to the treadmill for another run. Make sure your heart rate stays up the whole time to maximize fat burn.

If You Have 1 Hour

If you have the luxury of an hour to plan your workout, a more traditional approach would work better. Interval training is too strenuous and would be difficult to keep it up for this long.

To make the most of your 60 minutes, do 20-30 minutes of cardio at a fat burning zone (60-75 percent of your maximum heart capacity, which is calculated by subtracting your age from 220). Then move on to weights. Focus on doing longer sets (12-15 repetitions) with lighter weights, so your muscles can train longer. Remember to stretch at the end of the workout.

What Else You Should Know

- Never train the same muscle two days in a row. Not only can it cause injury, but it can also hinder muscle reconstruction and growth. You build muscle not when you’re training but during the rest and recovery period, so you need to give at least 24 hours for the muscle to recuperate before you train it again.

- Don’t stretch before you exercise unless you warmed up first. Otherwise, you can pull a muscle or cause more damage than good.