So it seems burning calories by jogging/running only depends on the distance covered, and not the speed. http://www.runnersworld.com/tools/calories-burned-calculator
Is this correct? Even if I ran the same distance in half the time I would only burn same amount of calories? It seems kinda overly simplistic.
It looks to me that the calculator is broken or missing information on input... when I tried to run it just now in my browser (Firefox v36.0 on Mac OS X 10.10.2) it wouldn't display a result at all. I suspect it's just broken, but don't know for sure.
Give this one a try and see if you get better results: http://www.mapmyrun.com/improve/calorie_calculator/
It appears to change the output based on the duration. In the test I ran, it changed by roughly 30% when I reduced the duration by half.
Nope, not in any sense, and not even if you were jogging in a vacuum, and could convert fat & carbohydrates anaerobically with 100% efficiency, to kinetic energy.
For a start you'll have Air resistance / drag, it's one of those Newtonian external forces, and it's effect is disproportionate (cube of your velocity), so the faster you move the more energy you need to expend to counter it. Sprinting 100m will consume more energy than walking it. Normal drag caused by the surface you're running on, and gravity due to the gradient you're running up / down are also external forces that will affect calories burnt.
Your body will also consume the: phosphocreatine, glycogen, and glucose available in your blood / mussels, before aerobically targeting your fatty acids (fat) reserves. So duration and your body composition will impact where your body decides to grab the required energy from, and as your body requires more Oxygen to convert fats to energy, you need to consider this. Once the phosphocreatine, glycogen, and glucose are depleted a VO2 (Volume Oxygen consumed) figure can be used to approximate calories / fat burned. Which highlights another body composition / fitness factor, the more laboured your breathing and the higher your heart rate the more calories you're burning. So fitness plays a role, or VO2max as it can be quantified.
Also worth a read:
I've noted this in another answer https://fitness.stackexchange.com/a/36045/26537 but the calculator is deceptively simple. The time does nothing. There is no speed component it's just:
calories burned = distance run (kilometres) x weight of runner (kilograms) x 1.036
Any calculations that do not take speed into effect are not worth much for higher speed running. I wlil try to find the study later: but in any case it was found that the primary contributor to calorie burning is exertion due to consumption of oxygen. This makes common and intuitive sense: you feel that you start working much harder at some point that is the limit of your current abilities to function. That speed might be an 8 minute mile for you but a ten minute mile for someone else. And that threshold changes over time.
Someone who finds doing an eight minute mile challengin but knocks themselves out (in the sense of high exertion) to complete a mile in say seven minutes is using quite a bit more energy than a younger version of me that could do a five minute mile but "leisurely" takes that same seven minutes instead.
