Definition of organism for English Language Learners. : 1  an individual living thing. : 2  a system with many parts that depend on each other and work together.
Figuring out how many calories you burn when running is, on a simple level, a fairly straightforward calculation. Most experts (and lots of studies) suggest that a person of average weight burns about 100 calories in a mile of running.
The same person burns about 776 or 863 calories, respectively, while running for 60 minutes at 5.2 or 6 mph. Walking's Just Fine. If you can't sustain a jogging pace of 5 to 6 mph, don't feel as though you're taking a physical step backward by choosing walking.