I know this piece will sting some deeply as I have found that those who do love ellipticals seem to really love ellipticals. But the fact of the matter is, ellipticals are pretty awful and if you respect yourself as an athlete - don't use them. Many of you already have given up this evil machine (there's a reason we don't have any ellipticals in CrossFit boxes). But if you are serious about performing optimally as a human, you will avoid this scourge of the modern athlete and think of ellipticals only as barriers in your path to the barbell area of the gym.
Here's the problem:
1) Reinforces poor motor programs. The arc of motion available on the elliptical causes you to heel-strike (if there is such a thing as strike on these things) too far in front of the center of mass which only serves to teach you to over-stride when you go to run. We already know heel-striking is costly and injurious. I also think it drives the femur forward in the hip socket repetitively via the iliopsoas and we never get to triple extension (full extension of the hip, knee, and ankle = maximal force). Furthermore, instead of falling thru the ankles as with proper running form - you smash into them while grinding and pulling each step.
Essentially, the entire arc of movement occurs in front of the body. Many clients I've ended up seeing report hip pain with symptoms of impingement when on an elliptical - not a surprise after they sit all day driving their femurs forward then reinforce that for 40 minutes on the elliptical while watching television. *If you can watch television while exercising, please don't call it training*
2) You can't feel the ground. Proprioception (joint position in space) is seriously limited on these things. When we can't feel the ground, we adapt thru maladaptive co-contraction (like walking on ice) in the leg musculature reducing movement efficiency for when it matters most - like doing actual athletic or sport movements, even walking. The timing of muscular onset and activity is crucial to movement efficiency and performance but on an elliptical you're just grinding through muscles that stay on way too long. And if you can't feel the ground, you can't generate force which is necessary in all athletic movements.
Don't believe me? How do you feel as soon as you get off the elliptical? You're gait is jerky, almost ataxic, and it feels like you're still floating. The knees stay bent throughout the gait cycle and you're looking for a foam roll as soon as possible - it's a nightmare.
*And why have injured athletes use this, especially as a warm-up? We just end up spending the rest of the training session undoing all of these faulty mechanics incurred on the elliptical.
3) "Low Impact". Ellipticals are marketed as low-impact. However, all the aforementioned co-contraction around the joints causes a lot of compressive forces - especially to the knee. The running literature supports this too, showing increased joint forces when running in cushioned shoes (which are supposed to lower the impact) vs. barefoot - the exact opposite of "low impact". Besides, ground-reaction forces are necessary to build bone mass. Essentially, we're getting all the negative joint forces from improper muscle activity without the benefits of skeletal loading.
4) Broken midline position (over-extended or over-flexed). The set-up of the elliptical really makes it difficult to maintain neutral spine, instead causing you to look like either a bent-over tree or a broken pole-vaulter. Glutes are under-used and hamstrings are over-used on the elliptical altering lumbopelvic control and contributing to the chronic hamstring and/or back irritation I've seen in clients who love the elliptical. No wonder gait mechanics are jacked up.
From CrossFit Endurance coach Jeff Ford:
If the goal is inefficient movement patterns, tight ankles, and trashed hips and low back by all means keep plowing away. But if you are serious about performance - whether it's becoming a better athlete or more efficient human - avoid the elliptical. If you require "low impact" activities due to injury (which is way over-prescribed anyways), consider that faulty mechanics are causing this injury. Simply improving those mechanics and reducing volume is the way to go rather than reinforcing them even more by jumping on the heinous elliptical.