Jillian Michaels' Top 5 Tips for Fast Results

Her new DVD, Body Revolution, is for moms like her with no time. These are the core principles. By Marisa Fox, REDBOOK.

1. Circuit-train
Move from one strength-training exercise to another in an aerobic fashion. You'll give your muscles--but not your heart rate--time to recover.

2. Go for high-intensity intervals
Work out at 85 to 95 percent of your maximum heart rate for 20 to 60 seconds every few minutes. This helps you burn more calories overall. Sprint when you run, or jump rope during a strength circuit.

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3. Mix up your routine
Add yoga, boot-camp classes, kickboxing, or any new activity to keep your body from plateauing. You'll be fitter, stronger, more flexible, and better balanced.

4. Up the ante
Every two weeks, set new, harder goals. Reach for heavier free-weights, do more reps, or try push-ups on your hands and feet instead of your hands and knees. When you challenge your body, you continue to get new results.

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5. Multitask
Training multiple muscle groups at the same time maximizes calorie burn and shaves time off your routine. Combine lunges with biceps curls, for example. Go to redbookmag.com/jmmoves to get more of Jillian's moves.

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