Which do you prefer?  Which do you consider more effective for a cardiac/aerobic workout?  What the advantages/disadvantages of each?

I currently have an elliptical machine, and I enjoy the low-impact workout - my knees are weak.  I'm just curious as to whether or not I should switch to running/jogging after they strengthen up...

the_reject

I like the nordic track type machines (I'm not sure if that is what you mean by elliptical). I hate running but I do this machine 5 days a week. I figure at least your arms are doing alittle more then when you are running.

Properly designed (suspended, cushioned) treadmills are an improvement over hard pavement. The absolute best running medium is the wet sand of a shoreline - provides plenty superb cushioning yet still plenty of traction for every step. Move over to the dry stuff if you want a calf burn.
[heavy]

Most effective is actualy running, but of course there is great shock to the knees and ankles.  Treadmill and elliptical would run a close second depending on how much you push yourself and how much you let the machine do.  Running a 6 minute mile on a treadmill is alot easier than running a 6 minute mile on a track.  Ellipticals are great because there is almost no shock on the joints.

Whether tredmill running or running on a track, make sure your sneakers are up to par.  I usually get a new pair ever 4 months.  Don't wait until you experience joint or back pains before you change your sneakers.

and like Ed has been advising, ALWAYS make sure your doctor has cleared you before starting any type of excersise program.

The only caution I would have about the low to no impact machines is that, while you get a decent cardio workout, it's the "impact" portion of walking/running that strengthens your bone density.  Maybe crosstrain with brisk walking on a treadmill and higher intensity cardio on the elliptical machines?

Also... for the love of Pete!... if you are going to walk at any fast pace DO NOT HOLD ONTO THE MACHINE unless you are elderly or extremely unstable.  It irks me to see people crank the incline up to 10% + and then hold on for dear life thinking they are getting some kind of super workout.  

I've found I get a better burn and better results if I slow down the rpm's and LUNGE for 20-30 minutes on a 10-15% incline.  If you think this is easy.... try it.  A guy who used to lift serious weights and run 6 minute miles started talking trash to me about it.  I set up the treadmill for him and he gave up after five minutes.  It is incredible for your gluts and upper thighs and your pulse rate gets jamming more than you would think.    

     I've got to agree with Miss Magnum on that latest post. I'm in year twelve as a C.S.C.S.(Certified Strength and Conditioning Specialist) and over these years I've found that one of the best things that you can do to make the treadmill work for you is to increase that elevation! Slow the speed down to 2.5 to 3.5 MPH and get that bad boy going uphill. The reduced speed makes it less ballistic and the increased elevation makes the exercise highly weight-bearing(not just flipping one foot in front of the other). I've got guys that smoke 10K's and you can just about wipe them out walking 3.0 MPH at  15 degrees for 30 minutes. Another machine that is pretty popular is the Climbing Systems by Staimaster(Formerly known as the stepmill and not to be confused with the stairmaster). It is the only piece of cardio equipment that has never seen anyone last longer than 30 minute on the highest intensity level.
       I think that I should conclude by saying that there is no best piece of cardiovascular machine out there because your heart will never know the difference between an eliptical/stairmaster/treadmill/rower-it is all relative to exercise intensity ie. metabolic equivalents(METS). Now, there will be a difference in the engagements of neuro-muscular units, but from a cardiovascular standpoint it all comes down to the intensity(and frequency and duration of the training, for that matter).

 Harp

When you mention Nordic Track, are you talking about the machines that simulate cross-country skiing?

I've tried those and found them very demanding.  Just staying balanced on the machine takes a bit of work.

The stairmaster is my favorite.  I feel like it gives me a better workout than the elliptical machines.  The elliptical machines are my second favorite though.  I really dislike running and therefore don't do the treadmill much.

Ed,

Could you identify the one your talking about from the Nordic Track web page?

[url]www.nordictrack.com/cgi-bin/ncommerce3/ExecMacro/category/nt/category_v4_home.d2w/report?cgmenbr=153&cgrfnbr=46525[/url]

Thanks in advance.

Another thing to consider is kind of fitness you are after.

If you are working out to lose weight, keep muscle tone, etc you can use a treadmill.

If you are training for a distance run, half-marathon or marathon, running the roads is the only way to go.  You can soften the impact somewhat by running on trails, dirt roads, and the shoulder when possible.

I don't believe you could get in race shape on a treadmill, or at least I never have been able to...

Hey, how about a 5K or 10K BRC race next year ??