You likely already know you need aerobic exercise for top physical fitness. But what is it exactly?

Aerobic exercise involves using a major muscle group, like your legs for instance, to elevate your heart and breathing rates for an extended period of time — most experts agree on a minimum of 10 minutes to qualify as aerobic. Walking, jogging, swimming, cycling, or using a machine such as the elliptical trainer all qualify as aerobic exercises.

What Qualifies As Aerobic Exercise?

When you’re getting a solid aerobic workout, you can feel it. In fact, one way to judge the intensity of your activity is by paying attention to your body. During a moderate aerobic session, your breathing is noticeably faster, but you don’t pant. You can hold a conversation fairly easily, but lose your breath if you try to sing a tune. It takes about 10 minutes to work up a sweat, and you only perspire lightly.

During vigorous aerobic exercise, your breathing is much deeper, and it’s hard to complete a full sentence without feeling winded. It takes just a few minutes to break a sweat, and you may perspire heavily.

Moderate and vigorous aerobic exercises both provide similar benefits, but the time requirements differ: the Center for Disease Control recommends 2 1/2 to 5 hours per week of moderate aerobic activity or 1 1/4 to 2 1/2 hours per week of vigorous aerobics.

It’s important to note that you truly need sustained muscle movement to get aerobic benefits from your workouts. Many shorter activities that appear on the surface to be aerobic are actually not and thus won’t provide the same heart and lung rewards. Running, for example, is aerobic while sprinting is considered anaerobic. That’s because during sustained activity, your muscles use oxygen to generate energy. During those short spurts of sprinting, your muscles don’t need oxygen for energy, so it isn’t aerobic. Other anaerobic exercises include lifting weights or jumping. If you sustain those activities for a long time without pausing, they become aerobic.

Health Benefits

Aerobic exercise comes with a host of major health benefits. The activity burns calories with amazing efficiency, making it easier to lose weight and maintain a healthy body size. Of course, no exercise makes up for a poor diet — you still need to watch your calorie intake.

Aerobic exercise also strengthens your entire cardiovascular system, helping to lower blood pressure, control high cholesterol, and prevent heart disease. If you’ve already suffered a heart attack, starting an aerobic exercise routine can help stop another one from occurring — so the activity truly can save your life.

If you’re feeling depressed or stressed out, aerobic workouts may come to the rescue. Exercising triggers the release of endorphins, which are feel-good chemicals in the brain. Aerobic exercise even fights aging. As you grow older, you naturally lose muscle tissue every year— but with aerobics, you build new muscle mass to replace what you’re losing. It also helps improve memory and fights dementia, keeping your brain sharp over time. As a general rule, people who exercise live longer than their couch-potato counterparts.

If you’re an athlete, aerobic exercise is especially critical to your performance. The endurance you build will carry over to your chosen sport. And by making your heart and lungs stronger, aerobic exercise helps make tough athletic challenges easier to tackle.

The Bottom Line

When starting an aerobics routine, don’t make the mistake of rushing into a long, tough regimen. You’ll only burn yourself out and start to dread the idea of exercise. Start slow – maybe with a 10-to-15 minute walk every other day. Then gradually up your exercise time and intensity to create a challenging program you can maintain for life.