Losing weight after 40 is not as hard as you think. Although strength-training is key, new research shows that how you train can make a difference between so-so results and a metabolism that stays in high gear, burning fat and showing off lean muscle. The secret is targeting a specific type of muscle fiber called type II, or fast-twitch, that’s responsible for bursts of speed and power. This type of muscle, like the name implies, is faster as well as denser, a combo that may yield quicker results.

These essential fibers, however, are the first to go as you get older (even if you’re active) because most workouts don’t target them. If you don’t use them, you lose them. Fortunately, there’s an easy antidote: speed. Research from salisbury University in Maryland found that lifting weights faster recruits more muscle and increases calorie burn by about 32%. That’s 72 extra calories per workout—the amount you’d burn walking a mile! The best part: you may feel stronger after just one workout. Combine it with our plan below to firm up your toughest trouble zones and drop a size this month.

More from Prevention: Foods That Rev Your Metabolism 

Workout at a glance

What you’ll need
One 6-foot flat exercise band (or two shorter ones tied together), medium resistance.

3 days a week
Do the 30-minute speed training strength Plan, below. Perform 3 sets of 8 reps of each exercise in the order listed, resting 30 seconds between sets, then repeat the entire routine one more time. Also do the 30-minute Speed Training Cardio Moves to fire up any dozing fast-twitch fibers in those hard-to-hit lower-body areas like your hips, butt, and thighs.

The rest of the week
Do 30 to 60 minutes of any type of moderate-intensity cardio—such as walking—as many days as possible to keep your metabolism revved and speed your weight loss.