Legs on a treadmill

Exercise the right way, and a cardio workout can do miracles for your health and your waistline. But if you take it too easy you’ll hardly see any results, and if you push too hard you’ll have a downright unpleasant workout or even injure yourself. A great cardio session is all about getting in the zone to build heart and lung strength and shed calories fast. Here’s how to get the most out of cardio, every time.

First of all, quantity matters. That’s why the Centers for Disease Control and Prevention recommend getting your tush to the gym (or trail or bike path) 150 to 300 minutes per week for moderate cardio. If you work harder and do vigorous cardio, you can get away with just half that time—75 to 150 minutes per week will do it. Schedule your workout times as you please—for example, 30 minutes, five days per week is just dandy—but each session must last at least 10 minutes in order to reap those fabulous cardio rewards such as reduced blood pressure, better endurance and weight control

So now that we have the time frames down, let’s discuss intensity. The best way to judge this is by measuring you heart rate. Don’t freak, it’s actually much easier than it sounds. The formula is based on your maximum heart rate, which you can figure out by subtracting your age from the number 220. So if you’re 34 years young, your maximum heart rate is 186. Simple so far, right?

Now to determine intensity: For moderate cardio, the Mayo Clinic says you should aim for 50 to 70 percent of your maximum heart rate; for vigorous cardio, go for 70 to 85 percent. So with a maximum heart rate of 186, you’re in the moderate cardio zone at 93 to 130 beats per minute, and you’re in the vigorous zone at 130 to 158 beats per minute. See, that’s not so hard.

If you’re wondering how to figure out your heart rate, here’s the scoop: pause from your activity and place two fingers on your wrist or at the top of your neck to check your pulse for 15 seconds. Multiply that number times four to get your beats per minute, which equals your heart rate. If you’d rather skip the math, just check your pulse for a full minute to get your reading.

If you really, really don’t want to deal with numbers, you can also go by your body’s own cues. During moderate aerobic exercise, you start to perspire after about 10 minutes but you won’t be sweating up a storm. You’ll be able to hold a conversation with your BFF, but you won’t be able to sing along to Adele on your iPod. You’ll breathe faster, but won’t be panting. When you’re in the vigorous cardio zone, it’s difficult to spit out more than a few words at a time, and you’ll start to sweat after just a few minutes. Your breathing will be fast and deep—and the work will feel pretty darned intense.

If you’ve been sitting on the couch for the past decade, it’s wise to start out with moderate cardio. If you’re a gym queen, go for the vigorous. By using these guidelines, you’ll get past the guesswork to make the most out of your routine.

image: SashaW