Since elliptical machines first became popular in the early 90s, there has been an ongoing debate about elliptical vs treadmill, and which provides a better cardiovascular workout. Recent studies suggest that both machines provide similar cardiovascular benefits, so the treadmill vs elliptical debate is now focused on the pros and cons of each machine. Here’s a rundown of the main points of comparison.

Several recent studies have concluded that exercisers burn about the same number of calories when working out on treadmills and elliptical trainers. Surprisingly, though, the studies have also discovered that exercisers reported a higher “rate of perceived exertion” while working out on a treadmill vs elliptical.

The rate of perceived exertion (or “RPE”) is a technique anyone can use to estimate how hard they’re working out. At a moderate RPE, the heart rate is elevated, but the exerciser can still carry on a conversation. Because the RPE on an elliptical trainer is lower, a workout on an elliptical may feel easier and more enjoyable, even if you’re burning the same amount of calories overall.

Researchers suspect that the perception of comparative ease in elliptical machines vs. treadmills may be due to the fact that elliptical machines work the entire body.

During an elliptical workout, the muscles of both the upper and lower body are engaged and working simultaneously, which provides and excellent cardiovascular challenge. But because no single muscle group is doing the lion’s share of the work, the perception of muscle fatigue is reduced.

The intensity of the workout can also be easily adjusted on both high-quality treadmills and elliptical trainers. Most high-quality machines come with incline adjustments and ready-made programs that can provide varied, challenging workouts.

For most people, workout intensity alone won’t settle the treadmill vs elliptical question, but check back soon for more facts that may help you make up your own mind.

Some proponents of treadmills say that treadmills provide a more “natural” workout because no special expertise is required to walk or run. But that’s only one component of the treadmill vs elliptical debate.

While it’s true that treadmills allow us to walk or run with a relatively natural stride, the motion of the belt forces the front of the leg to work harder than it would on flat ground. This is because, when someone is running on a flat surface, the hamstrings and gluteal muscles are engaged every time a runner “pushes off” the ground. This motion isn’t quite as pronounced on a treadmill, and can result in muscle imbalances for runners who train exclusively on a treadmill.

Another factor to consider in any treadmill vs. elliptical comparison is the fact that treadmills don’t completely eliminate the impact of each footfall. When we run, our heels strike the ground with an impact equal to 2.5 times our body weight. The cushioned bed of a treadmill may help absorb some of this impact, but it doesn’t resolve it completely.

In contrast, elliptical trainers involve no impact to the joints whatsoever. Elliptical machines offer a low-impact workout that imitates the elliptical motions of our foot, the expansion of our legs, and the natural rotation of our hips. This is one reason why elliptical machines are so popular for rehabilitation after an injury.

Elliptical machines also work the entire leg through a fuller range of motion, which can actually be beneficial for the joints. The oval motion of elliptical trainers can help joints increase their flexibility and mobility, which may help prevent some forms of joint pain later in life.

Of course, these are only some of the factors that play into the treadmill vs elliptical debate.

The last aspect of the treadmill vs elliptical debate focuses on how much workout variety each machine is able to provide. Workout variety is a critical component of any well-rounded exercise plan, because it reduces the risk of boredom and injuries. Adding some variety to the workout also offers significant health benefits, because it prevents the body from becoming too accustomed to a particular routine.

Some fans of treadmills point to the fact that most higher-end treadmills now offer set programs that include warm-ups, hills, sprints, low-output intervals and cool-downs. There is no arguing with the fact that using these programs on a treadmill will help increase the runner’s overall speed, conditioning and endurance.

But what many people overlook in the treadmill vs. elliptical debate is that the better elliptical machines offer similar program options. Better elliptical machines’ programs increase the incline and resistance for varying periods of time, which encourages the exerciser to “push” him or herself harder than they may otherwise.

Like treadmills, elliptical machines also allow users to manually adjust the speed, resistance and incline—which can be “mixed and matched” to provide a truly fun and challenging workout.

But elliptical trainers do offer one advantage over treadmills: The foot pedals on an elliptical machine can be operated in both a forward and a backward motion. Each time the exerciser changes the direction of the pedals, he or she is targeting the leg muscles differently. This can help promote a more varied, more challenging workout—and it can also help prevent some of the muscular imbalances that may be seen from running exclusively on a treadmill.

So, what’s your conclusion in the treadmill vs elliptical debate? Both machines provide excellent cardiovascular workouts. Consider the other factors we’ve just discussed and decide the treadmill vs. elliptical question for yourself, once and for all.