Your Exercise/Activity with the Highest Calorie Burn?

In an hour of running at 6mph (10 min miles) I can burn a net of about 720 (most of the other readings from HRMs and cardio machines are gross calories and are double counting BMR).

I have to respectfully disagree. Sure, if I put in 100% vs 50% on the same workout, yeah, it'll be obvious enough that I'll burn more when I put in 100%, BUT, let's say I put in 100% on the above-mentioned workout, versus 100% on some sort of strength training workout for the same amount of time. I will DEFINITELY not burn the same amount of calories. For both workouts I'd end up drenched in sweat, by I'd get in around 400 calories for the cardio one while 200 if I'm lucky for the strength training workout. Granted, strength training has its other benefits, but it certainly wouldn't be the most efficient activity for highest calorie burn.

I was under the assumption you're talking activities you can actually measure calorie burn. Which is cardio. And thats it.

That's fine, same concept applies...the difference may not be as drastic as between strength training and cardio (where cardio burns double for same amount of time), but there still could be a 100 - 200 calorie burn more when you go all out on, say, the cycling machine, versus all out on the treadmill.

Also, I'm guessing you're saying "measure" as in with HRM machines...cause that's true that HRM gadgets can only measure cardio. But other devices such as the FitBit and the BodyMedia Fit (BMF), which I own, can measure EVERYTHING

No, they cannot measure lifting. Or any activity for that matter accurately. It shows a gross misunderstanding of how the body works if you think this is true.

And lifting can burn as much, or more calories compared to cardio. If you know how to lift heavy. Most do not, and cannot so it's a moot point. but ask any lifter who is strong how much a pain in the *kitten* it is for them to gain weight...

High intensity Zumba
Les Mills BodyAttack
Les Mills BodyCombat

I'm in the 6 or 700s for an hour on a good day.

I use a HRM and have found that when I do Leslie Sansone's 5 Really Big Miles DVD I can burn about 530ish calories in about 51 minutes or so. That's with only doing 3 miles. I use 2lb hand weights for the first mile and that really boosts things. This is a huge burn to me because it's not so strenuous that I feel like I'm about to die during the workout.

Running uphill is better than just about anything else, but my feet can't handle it. I crank up the resistance on an elliptical trainer, and do HIIT, when I want to burn some calories as fast as possible.

I do indoor rock climbing at least once a week and according to map it's almost 600 in only 30m I think it might be a little high but I know it's a crazy good work out. Same with hiking ( I hike with a 30lb pack ,my two year old) and is a good outdoor workout

Taken straight up there are probably higher calorie burners per minute than cycling. BUT...

If you're aiming for time management and looking to max out your calorie burn per minute of time dedicated to exercising, cycling as transportation blows a lot of the more strenuous stuff out of the water.

Example: my ride to work. Driving on the interstate takes about seven miles and twelve minutes. Current riding route one way takes eight and a half miles and about forty two minutes, plus it burns about 450 calories at my current height and weight. There is also a shorter route about the same length as the driving route, which would take thirty five and burn 370. Getting to work is not optional so subtract twelve minutes from riding time. Doing this results in a burn of 370 for twenty three minutes on the shorter route and 450 for thirty on the longer route. Running would produce a similar burn rate to the shorter route at nearly eight miles an hour and the longer one at seven miles an hour. Without subtracting out the would-be drive time the calorie equivalent of the longer route for a similar timeframe would be done at five miles an hour.

Never mind that none of the mentioned running scenarios are realistic alternatives at my current fitness level.

Doing HIIT I get through about 800 calories in an hour

I burn roughly 600 in an hour hiit session.

How are you three able to do a HIIT workout for 1 WHOLE HOUR??! I'm usually dead by 30 minutes...I heard that HIIT workouts supposedly raises your calorie burn for the entire day despite not being significantly much during the workout. But when I check my BMF on it for my daily calorie burn, it never seems like that's the case

My thoughts exactly, I can barely get through 20 minutes and I am in good shape, usually I stick to 12-15 minutes. Otherwise it is just intervals, not high intensity intervals.