Do different exercises burn the same calories if maintaining same heartrate/timespan?

Can someone assist me in answering this question? I've looked up intensity and heartrate and everything, but I can't seem to find a definite answer.

Say a 14-year-old jogs on the spot for 30 minutes maintaining a 160 beats/min heart rate. This shouldn't be considered "moderate" aerobic exercise, correct? Because 160 is about 77% of a 14-year-old's maximum heart rate. Therefore, how does one calculate how many calories are being burned? Say, that same person keeps their heart rate at 160 on a stationary exercise bike for 30 minutes.

Is there a difference in calories burned? Any advice would be appreciated. :D

This is actually and interesting question and one that seems simple to answer but isn't.  Based on calorie burned charts, one would assume that different activities burn calories at different rates and one could assume that this is because of the different amounts of muscle mass engage by the different activities.  But if one beleives that heart rate monitors can determine the number of calories burned but can't know whether you are running, cycling, walking, etc.  then one would have to assume that there is a formula that can be used to convert the amount of time one spends at varying %s of max heart rate into calories burned.  But a search of the internet doesn't turn up one of these formulas.  In fact, it seems that the heart rate manufactures do not share their formulas with us or each other or anyone else for that matter. 

Also it is not correct to assume that two 14 year olds jogging for thirty minutes at a heart rate of 160 would burn the same number of calories.  And it is not correct to assume that they would both be working at 77% of their max heart rate.  Because there is no proven relationship between age and maximum heart rate or resting heart.  Resting heart rate is effected by fitness level but maximum heart rate is largely genetic.

So yes, there are fomulas for converting effort as measured by heart rate into calories burned but it is odd that those formulas are not available.  Maybe someone with better Google skills then mine can uncover one.

I'm really glad this came up.  I've been wondering about this as the machines at the gym calculate wildly different calorie levels.  The elliptical trainers will like me  to believe that I can burn 100 calories in about 7 minutes without barely breaking a sweat, while the cardio wave (the machine that simulates inline skating) doesn't calculate 100 caloires until I've sweated at a high heart rate for 15 minutes. 

I've been assuming that it's all a wild guess, and the fact that trhawley couldn't find any info seems to support my guess.  If it was so easy to calculate, then we would find it as easily as a BMI calculator, right?

you will normally burn more calories on a weight bearing exercise like running compared to riding a bike. the problem with machines is they have no idea what your body composition is, so the calories burn could be way off. The same goes for the heart rate monitors, that's why i never recommend getting them, you take your pulse the old fashion way and save some money.

The rule of thumb for me is keep your heart rate elevated you will burn calories, i prefer duration and intensity as measuring guide.

I think duration and intensity is an excellent way to measure calories burned but how are you converting that into a number?

A little more digging turns up information about METs or metabloic equivalents.  There are formulas for estimating calories burned based on duration and intensity where intensity is translated to a MET.  These appear to be quite subjective.

If i really is all about duration and intensity, then that suggests that the heart rate monitors might actually work.  Of course, they could be off; as bodyscience points out - they don't know your body's composition.  Then wouldn't they at least  be consistently off and give you relative burn rates for different activities?

Well, not to confuse things even more My HRM which is programmable to my height weight sex age and even gives my VO2 index will tell me I burn different amt of calories for basically the same exercise -- so one day doing weights I might burn 245 cals when the next time I do that routine I'll only burn 150 -- lots of things effect cal burns.  The temprature, your stress level, how much sleep you got the night before, even what you ate that day can effect cals burned. 

Basically cal burns aren't an exact science and shouldn't be taken as gospel,  I think the activity browser will give you a pretty good guestimate of cals burned for each activity but I'm gonna say the jogging is gonna burn more cals because you are working the large leg muscles and probably some arms too, where the bike is only legs and not weight bearing like someone else mentioned.