Is any particular one better for staying in shape, both cardiovascularly and as far as muscle/fat goes?

According to online calculators I've seen, running typically burns much more calories for the same amount of time

slight sidebar...cycling is easier on your joints.

Yes, running generally does burn more calores / hour than cycling. It also is rougher on the joints, but, that pounding is good for improving bone density! Both have benefits and drawbacks. I prefer cycling because I go faster and I find it less boring. I run for triathlon training.

Why not do both?

Well I pretty much do both right now, I was just wondering what the pros and cons were. I guess mixing in both is best?

If you were interested in becoming a better cyclist or runner, I would recommend doing that one almost exclusively. But, if you are interested in improving your overall fitness, I think a mix of the two is a very good cardio plan.

Then, you could enter a duathlon (run - bike -run).

Hmm I guess I'll just stick with both then.

I would rather run, but that is jsut me.

well, thanks lol...that doesn't help much, but enjoy your runs

I like to do both...I mean I've been biking for like my entire life and only started running about a year or a little more ago to help in my weight loss diet....but now I do enjoy it, and I enjoy both now

According to the readings on the bike at the gym, I burned 678 calories in just over an hour today could do that in just slightly more than half the time if I was running I think. Are the numbers really that different? Is there a good number to shoot for per session, or is that irrelevant?

Running doesn't burn twice the calories as biking. Running burns about 110 calories / mile so if you are running 8min miles, that will be about 800 miles / hour.

Comparing Cycling With Running

I like running more, if i bike its either straight down rocky trails or if there is no gas in my car haha

I don't care what anyone says....

There are only 2 types of runners: those who have blown-out their knees...and those who will blow-out their knees!

I prefer cycling. I sweat like a pig and I just couldn't carry enough water with me if I ran.

Hey SkiBikeSwim...what kind of a silly screen name is that? Me and StrokeSmackSpank think you're copying us....what's up with that?

well I run on an incline or do intervals on the treadmill and I burn between 900-1000 calories an hour according to it's readings. Even if you use a calculator for a 7min mile for 35 minutes, which is about what I can do, it says 517 calories burned
Bodybuilding.com - Calories Burned While Exercising.

if you look at the bicycling (stationary) one, it's between 250 and 390 calories for that same amount of time, depending on if the exercise was moderate or vigorous...so it's close to double according to this calculator....how do you know what "vigorous" is anyway....I biked 22.29 miles in 60 min, would that be considered moderate or vigorous? Can you determine this by the average rpms or what?

22.29 miles/hour on a road bike would be hauling @ss - definitely vigorous. On a stationary bike, it would not be as hard, but would still be vigorous I would think.

I don't trust the calorie burning estimators on the machines. Go with a web page estimator, like bodybuilding.com, and just do it.

Well I just showed you numbers from BB.com lol and I was told before that that running doesn't burn twice as many calories....However, clearly, it does (almost) according to bb.com

Should I aim for a certain number of cals burned per cardio session, or just focus on total time?