Calories burnt - believe activity log or the treadmill?

I ran for 70mins today (walk/run) - treadmill said 675cals burnt.  If I plug that into CC it comes out with more.

Personally I always put in the lowest burn or the highest food and that you know that worst case scenario is that you are underestimating and not going to be sadly disappointed at weigh in :)

I just got a heart rate monitor and it says I am burning LESS on the treadmill (more if I run outside) than it says...which is depressing, but helpful and motivating at the same time.

Both the treadmill and CC estimate the calories burned based on your weight and age - CC may take into account your activity level as well, I don't know.  Neither take into account your ease of the task. 

If running/walking is something you do frequently, you might not have burned that many calories.  If you are relatively new to the exercise, then it is possible. 

How winded and tired were you?  How fast did your heart go?  How depleted did you feel afterward?

The treadmill also takes into account the exact speeds you were going at - if I remember correctly, CC uses a range.  I would probably go with the treadmill's estimate.

Fitness equipment is grossly inaccurate.  We have found machines to be about 1/3 more than actual...for example if the machine says 200 calories you probably really burned about 140.

Best...use a heart rate monitor.  They are also great feedback to motivate you to work harder.

I go by the CC numbers simply because the machines don't know how much effort you're putting in. A lot of them measure your heart rate, but that doesn't figure into their calories burned number. My heart rate on the machines I use is always in the "cardio - high intensity' area so that is a consideration when I plug in my numbers here on CC.

I don't know about your treadmill, but mine doesn't ask my weight.  I was told by a physical therapist friend that unless a piece of exercise equipment asks for your weight, it is set for a person weighting in at around 150.  I weight in at approx 113 (sometimes a pound more or less, depending on the time of day, water weight, and time of month (doh)).  My treadmill tells me I burn 770 calories at the end of my run, and CC tells me I burn 350.  I am more prone to believe CC.  Sad, but true. 

Well I went out and got the Polar F7 HRM.  Strapped it on and went for a 3.2mile jog this morning on the treadmill. 

Treadmill:   404cals
HRM:        ;   385cals

I'm happy to report that it seems they are pretty even! 

(btw I have the reebok irun treadmill)