If youve ever followed a race training plan, you know its not just about running; its about running strategically. Thats why there are easy runs, long runs, speed runs, tempo runs, recovery runsits enough running to fill at least five or six days a week, and it can eventually do a number on your body.

The reason training plans call for so much running is the rule of specificity: Whatever you want to get good at, you have to do that type of activity to a pretty high degree, explains Ian Klein, a specialist in exercise physiology, cross-training, and injury prevention at Ohio University. Translation: To be a better runner, you have to run more. Each specific running workout has a purposefrom developing fast-twitch muscle fibers for speed to building your endurance to helping your tendons, ligaments, joints, and bones adapt to the stress of runningwhich is why its important to include all of them in a training plan.

That said, theres a little flexibility when it comes to the recovery run. The low-intensity recovery runwhich is generally done at less than 70 percent of your maximum heart rateis crucial for maintaining the base of your aerobic fitness and developing oxygen efficiency in the muscles, says Klein. But if youre injury-prone, dealing with small niggles or joint pain, or even just approaching burnout, its one workout that you can take off the road or tread and onto another piece of equipment: the elliptical.

The elliptical was literally invented to mimic the motions of running without the impact caused by runningso youre going to get a more running-specific cross-training workout than you would on a bike or in a pool. But running on the elliptical eliminates the weight-bearing and muscle-pounding that running produces, says Todd Buckingham, Ph.D., an exercise physiologist at Mary Free Bed Sports Rehabilitation Performance Lab in Grand Rapids, MI.

What the elliptical does is take out the eccentric contraction, that moment when you land and prevent your body from collapsing, explains Klein. That is an integral part of running, so you do need that training; but if you get too much of it, he adds, your muscles can fatigue and break down under all that stress, which can lead to injury.

The elliptical also cuts out the push-off phase of the gait cycle, because your feet never leave the pedals. Thats not necessarily a bad thing, says Juan Delgado, C.S.C.S., director of Sports Science at the NY Sports Science Lab in Staten Island, New York. When running, the tibialis anterior muscles (which are responsible for dorsiflexion of the feet) are never under maximum tensionwhich makes them more susceptible to overuse and makes you more prone to shin splints, Delgado explains. But when youre maintaining constant contact with the elliptical pedal, these muscles will have a better isokinetic and isometric contractions, becoming stronger without the impact of the lift-off/heel strike motion, he adds.

Plus, the elliptical is more of a complete workout, equally recruiting the upper and lower body with its pendulum motion. By using your body weight as resistance, it becomes an excellent way to prepare your body for the rigors of regular running, since the muscles engaged in running will become stronger and more accustomed to carrying the body weight without the impact of hitting the floor constantly, says Delgado.

Because the elliptical is a non-weight-bearing activity, it will feel easier than a run of similar intensity. To combat this, use the elliptical for 1.5 to 2 times the duration of your run, says Buckingham. For example, a 30-minute run would be equivalent to a 45-minute to one-hour elliptical session.

Subbing in elliptical sessions on recovery days can be especially helpful for runners who have a tough time actually sticking to a recovery pace (or less than 70 percent of your maximum heart rate). Its actually pretty hard to get your heart rate up on the elliptical (without maxing out resistance), which means youll actually stay in the easy, low-intensity zone you need to be in to get the benefits of that workout.

Because using the elliptical can improve blood flow to the muscles without causing the muscle fiber damage that running does, it could actually help speed the recovery time between hard running sessions and allow you to complete your hard running days at a higher intensity, says Buckingham. And if hard days are performed at a higher intensity, performance gains will be greater.

Thats why you should always do your key workoutsspeed runs, tempo runs, and race pace runsas running efforts, says Klein. No matter how closely the elliptical was designed to mimic running, anyone whos ever stepped on a machine knows its not a perfect match. Consider it a valuable tool in your arsenal, especially on days you need to slow it down or get a little extra recovery, but not as a replacement for running.

See more here:
Can You Use the Elliptical for Recovery Runs? - runnersworld.com