Calories burned on Fitness Equipment?
How accurate are the counted calories burned on fitness machines such as the treadmill and elliptical? I know that a heart rate monitor would be more efficient in telling you how many calories you have burned while working out, but if I don't have one what are my options?

If possible, before you go to the gym go to a website like "buddyslim.com" that has a "Calories Burned" tracker and find the activity you are going to do (such as a rowing machine w/a calorie counter screen), enter the time and see how many calories it says you will burn.

*Note: It does have different levels that you will be doing the exercise (vigorous effort, light effort, etc).

Then, do the exercise for as long and with as much effort as you entered in the tracker and see how the number you get compares.

Also, you could reverse this order and do your exercise first if you don't know ahead of time what you might do.

(P.S. I saw on another question you wrote in Diet & Fitness that you are 20 years old - I am too! You should really consider joining buddyslim.com! It's so great - It's like Myspace for people on diets. They have all sorts of trackers (calories eaten, calories burned, weight) and you can even set minigoals, which make you feel a lot better about losing weight! Check it out!)