If you feel like you're getting a vigorous workout, you probably are.
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Variety is the key to beating boredom and keeping your workouts fresh -- but you may be concerned about the progress you'll make if you choose one type of workout over another. Some people consider running to be one of the most effective workouts for burning calories and staying in shape, although plenty of other exercises can provide similar effects. To compare the elliptical trainer with running outside, take a look at some common markers for the intensity of the workouts.
One way to compare workouts side-by-side is to look at the number of calories you'll burn doing one or the other. If you weigh 155 pounds and you use an elliptical trainer for 30 minutes, you can expect to burn roughly 335 calories. You'll burn the same amount if you run for 30 minutes outside at a pace of about 5.2 mph -- or an 11.5-minute mile, according to Harvard Medical School. Naturally, running faster than that will burn more calories.
Comparing Heart Rates
Another way to determine whether one workout is more intense than another is to test your heart rate. Heart rates vary widely depending on a person's age, gender and overall fitness level, so don't compare your heart rate to others'. The ideal heart rate for cardiovascular exercise is between 50 and 80 percent of your maximum heart rate, according to the American Council on Exercise. Calculate your maximum heart rate by subtracting your age from 220, and then multiply that number by .5 and .8 to determine your target heart rate zone. Try doing a 30-minute running and elliptical session on different days, and place your pointer and middle fingers on your carotid artery for one minute mid-workout. Compare your heart rates for the two exercises to find out which one is more intense for you. A higher heart rate means you're working harder and likely burning more calories and fat.
Your personal preference should also come into play when you're trying to decide between one exercise or the other -- although you may find other reasons to choose the elliptical over running outdoors. For one, the gentle "elliptical" foot motion of elliptical trainers offers a low-impact workout that is less painful for those with joint pain. And since ellipticals allow for a forward as well as a backward motion, they'll let you work your muscles in slightly different ways throughout the workout. The trainers' computers also let you monitor the time elapsed, the estimated calories you've burned and other factors related to the workout.
Outdoor Running Benefits
Running, meanwhile, has its own set of benefits. With the changing scenery of the outdoors, you're less likely to get bored than you might while doing the same repetitive motions on an elliptical. You also won't have to fuss with a machine if you decide you want to do an interval workout or change the pace of your workout. And since most cities offer dozens of fun runs and races throughout the year, running can be a more competitive, social activity than simply using an elliptical at home or at the gym.