Generally I do about 45 to 60 minutes of cardio a day, on the cybex hill-style eliptical to the point where the calories burned counter gets to around 900 or 1000, give or take. Occasionally I'll go way up to 1400 and sometimes just cut out at 800 or so. But 1000 is my average.
Rambling, sorry. My question is last night I didn't have as much time so I set the timer at 30 minutes, but boosted the level up a couple notches. It was a much harder workout than usual, and by the end I was drenched more than usual, even all of my shorts were thoroughly soaked. Soemthing that normally doesn't happen. I was frustrated to find out I had only burnd about 700 calories. Apparently judging by sweat is not at all accurate, I thought it might be.
Is the calorie counter just very unreliable, or am I not getting as much out of my shorter, but harder workouts such as these?

Thanks

Becks-

The calories are determined by distance, run a mile walk a mile - burn the same calories. The difference is time and the areobic benefit. Also, the calorie counters on many machines are not that accurate. I generally have people do 4-5 days of cardio and a max of 45 minutes, once they reach 45 minutes I increase intensity. I have found that too much cardio can catabolize muscle.

Is that really completely true? It's very hard to imagine that if you SLOWLY walk one mile, and then run one at a good clip, you will burn the exact same amount of calories. Although, as I write that, I guess it's POSSIBLE? I dunno, Maybe depending on the acitivy and duration it matters that way as well?
So my workout last night, much harder but a bit shorter, although I felt much more worked, essentially did less for me? Is that a bad thing to do? Or is it something I should do like once a week? I know the trainers said to do stuff like that occasionally to boost your HR, but I always do interval training for that. What would you say?

Thanks

It would also have the benefit of boosting your metabolic rate for a period of time after you stopped.