Will walking work just as well?

Walking a mile burns roughly the same calories as running a mile. (It just takes longer to do.) So walking 30 minutes won't replace 30 minutes on the elliptical -- but it's better than nothing.

Edited to say that sounds snarky when I read it back. Sorry! I've lost all my weight from logging, walking, and yoga. So walking definitely works!

Walking a mile burns roughly the same calories as running a mile.

No, it doesn't, it burns half as many calories.

Walking a mile burns roughly the same calories as running a mile.

No, it doesn't, it burns half as many calories.

This article from Runner's World, "Running v. Walking: How Many Calories Will You Burn?" (http://www.runnersworld.com/weight-loss/running-v-walking-how-many-calories-will-you-burn), concludes that the burn from running is about 50% higher than from walking: 158 calories vs 110 calories for the sample person cited. So walking burns about 2/3 as many calories -- not the same, and not half.

The Runner's World article cites these two papers as sources:
"Energy expenditure comparison between walking and running in average fitness individuals" (http://www.ncbi.nlm.nih.gov/pubmed/22446673, J Strength Cond Res. 2012 Apr;26(4):1039-44)

"Energy expenditure of walking and running: comparison with prediction equations" (http://www.ncbi.nlm.nih.gov/pubmed/15570150, Med Sci Sports Exerc. 2004 Dec;36(12):2128-34)

The "Energy expenditure comparison" article also says that "Walking and running are both acceptable activities that increase EE above rest and can be performed without the expense of a health club membership and meet adequate kilojoule expenditure according to American College of Sports Medicine guidelines."

walking is how the world stays slim

As a temporary option (or all the time!), walking is excellent. I've lost over 50 pounds using walking and hiking as my primary exercise. The most critical thing is to STAY ACTIVE, so you are on the right path by not telling yourself, "oh, no elliptical, and my hip hurts, so I'll just take time off". If you want the walking to be more effective, you might try some intervals - walk for a while at a normal exercise-walking (not strolling) pace, then walk as hard and as fast as you can for 60 seconds. Uphill is good. After a minute, slow back down to the previous pace for a few minutes. Repeat a few times. Doing this even once per week, with regular walks in between helped me overcome a plateau about 10 pounds ago.

Good luck! Enjoy your vacation and stay the course!

The most critical thing is to STAY ACTIVE, so you are on the right path by not telling yourself, "oh, no elliptical, and my hip hurts, so I'll just take time off".

This is what I was trying to say, but I'm not as eloquent as andysmom. (And I'm so, so sorry for having caused a derail.)

I lift weights, and at times I hike enough to burn 3,000+ calories. But walking at at least moderate pace is how I create a deficit to lose weight: hiking with a pack and weight lifting both make me so much hungrier I tend to eat back all the calories burnt and then some. Walking however, does not cause me to over eat. So yes, it works just as well, if not better for many.

I burn about 125 calories per mile if I run and about 80 per mile if I walk (this is with a HRM). walking is so much better than holding down the couch and doing nothing and it is also a great way to keep that healthy exercise habit going.