Spread out or all at once, is there a difference?

Greetings fellow calorie accountants.

My question really is a simple one. Is there any benefit / difference to doing exercise that amounts to the same calories burned in one "go" or spread outdifferent times during a day?

I try to get on the elliptial trainer for 30 mins / day which at my current age / weight / sex (25/289/M) tells me I burn 500ish calories. A (pretty hilly / vigorous) ride to work on my bike burns about 250 calories each way. I need to start working 12 hour days, so skimming the hour it takes to hit the gym daily and replacing it with the bike-ride would be of great benefit to me.

Am I getting the same benefit phsycially by doing two separate 250 cal stints vs. one 500 cal stint?

I can think of pretty sound reasons why and why not, so, I'm appealing to anyone on here who has any kind of factual basis on which to give me an insightful answer to the question, and why.

Thanks in advance!

PS. I was asked if riding my bike added time to my commute, and the answer is no; rush hour traffic means long waits at red-lights which I can now avoid :D

"What I've always read is that by splitting up your work-outs throughout the day, you will actually burn more calories during the course of the day because you are getting your heartrate and metabolism up 2 times instead of just once.
It makes sense and I appreciate the facts from the research..." " There was soem research done on this very topic from the Washington State website, which is currently under construction, but it concluded that, from the testing they had done, the two sessions produced better results than one session.The multiple sessions were kept fairly short though, 15-20 minutes I think." Check out this web site for more info (that is where the above came from) = http://training.fitness.com/current-trends/mu ltiple-short-workouts-vs-long-one-3736.html

Nice info, thanks.

:)

This is an interesting post seeing as I recently started to split up my work outs. I do about 30-40 minutes of cardio a day but instead of doing it all at once I split it up into 3 different sessions. This helps me out a lot because exercising boreds  me to death ( I think I get ADD when I work out :p) so doing 10 minutes sessions keeps me focus and allows me to actually have a nice work out by then end of the day!

I'm really glad you asked this; I was going to ask it myself.  I have started to break up my work-outs into 2 sessions - 3 miles in the AM and 2-3 in the PM and was wondering the same thing.  Thanks, all for the responses. - Wanda