If I had a nickel for every time a female client told me they didn’t want to lift weights for fear of “getting bulky,” let’s just say I would have lots of nickels. While, yes, there is a purpose for dieting and cardio, the truth is that lean muscle cannot survive on the treadmill alone. In my experience, weight training still seems to be the biggest-kept secret for fat loss.

You should know that unless you’re taking supplements to enhance muscle growth you won’t get bulky, because your body simply doesn’t have the hormones to get there naturally. Cardio only burns calories while you’re performing it, but strength training has what is known as the afterburn effect. Thanks to “Excess Post-Exercise Oxygen Consumption” or EPOC, your metabolism remains elevated even after you’re done exercising. A well-designed strength-training program can keep you burning calories and fat for up to 48 hours after your workout.

Here are four things your fitness regimen should include, plus a sample workout schedule.